text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1944 08

P.03 - Contents Banner
The Australasian Radio World

Devoted entirely to Technical Radio

and incorporating

All-Wave All-World DX News

Vol. 9 - AUGUST, 1944 - No. 3

P.03 - Publication Notes
Proprietor - A. G. HULL

Manager - Dudley L. Walter

Secretary - Miss E. M. Vincent

Short-wave Editor - L. J. Keast

For all correspondence: City Office - 243 Elizabeth St., Sydney -  Phone MA2325

Office Hours - Week-days: 10 a.m. - 5 p.m., Saturdays: 10 a.m. - 12 noon

Editorial Office - 117 Reservoir Street, Sydney

Subscription Rates - 6 issues 5/3, 12 issues 10/6, 24 issues £1, Post free to any address

Service Departments - Back Numbers, 1/- ea., post free; Reply-by-mail Queries, 1/- each

Printed by Bridge Printery Pty. Ltd., 117 Reservoir Street, Sydney, N.S.W., for the proprietor of the "Australasian Radio World," 117 Reservoir St., Sydney (Footnote P.28)

P.03 - Contents
CONTENTS:

CONSTRUCTIONAL -

Home-Made Hi-Fi Pick-up. . . . 5

Wide Range Audio Frequency Oscillator. . . . 7

A Useful A.C. Bridge Circuit. . . . 13

V.T. Voltmeter for Audio Work. . . . 18

TECHNICAL -

The Accuracy of Ohmmeters. . . . 9

Screening by Metal Spray. . . . 11

Frequency-Controlling Crystals. . . . 17

Bass Booster for Amplifiers. . . . 19

SHORTWAVE REVIEW -

Notes From My Diary. . . . 20

New Stations. . . . 20

Shortwave Notes and Observations. . . . 21

Shortwave Schedules. . . . 24

THE SERVICE PAGES -

Answers. . . . 26

P.03 - Editorial Notes
Editorial

The war effort has called upon the radio industry to supply huge quantities of equipment. Radio receivers and transmitters are required for fitting to practically every tank, plane, and boat. Hundreds are required for the maintenance of communications between various groups of men in action. The demand is being met in a marvellous way, considering the problems of production, but sometimes it is found that schedules cannot be maintained. Almost universally the explanation is that sufficient manpower is not available. Quite unofficially, we happened to go into this problem with a well-known factory executive and immediately formed the opinion that the problem was not really so much a matter of shortage of hands as the inefficiency of those employed. This was due, primarily, to the fact that the executives of the organisation were themselves overloaded with work. In this particular case the production was three times what would have been a rush in peacetime, yet there were fewer executives on the job. Needless to add, these executives were not in fit shape to get the best out of the employees. No one seemed to have the time to spare to see to the proper up-grading of the more intelligent "unskilled" workers, yet we feel sure that such time would not have been wasted. In fact we suggested that an intensive schooling of a few of the better-type staff, in this case especially senior females, would eventually lead to improved quality as well as quantity of production by removing a severe bottle-neck in the testing department. At any time, the overworking of executives does not lead to efficiency in the long run. - A. G. HULL.


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1944 09

P.03 - Contents Banner
The Australasian Radio World

Devoted entirely to Technical Radio

and incorporating

All-Wave All-World DX News

Vol. 9. - SEPTEMBER, 1944 - No. 4

P.03 - Publication Notes
Proprietor - A. G. HULL

Manager - Dudley L. Walter

Secretary - Miss E. M. Vincent

Short-wave Editor - L. J. Keast

For all correspondence: City Office - 243 Elizabeth St., Sydney -  Phone MA2325

Office Hours - Week-days: 10 a.m. - 5 p.m., Saturdays: 10 a.m. - 12 noon

Editorial Office - 117 Reservoir Street, Sydney

Subscription Rates - 6 issues 5/3, 12 issues 10/6, 24 issues £1, Post free to any address

Service Departments - Back Numbers, 1/- ea., post free; Reply-by-mail Queries, 1/- each

Printed by Bridge Printery Pty. Ltd., 117 Reservoir Street, Sydney, N.S.W., for the proprietor of the "Australasian Radio World," 117 Reservoir St., Sydney (Footnote P.28)

P.03 - Contents
CONTENTS:

CONSTRUCTIONAL -

The "Ferrier" Super Crystal Receiver. . . . 10

A Non-Microphonic Volume-Expander Circuit. . . . 13

Simple and Effective Valve Tester. . . . 15

TECHNICAL -

N.Z. Radiomen to go to Britain. . . . 5

The Design of Direct-Coupled Amplifiers. . . . 6

Eclipse Staff Holds Amplifier Contest. . . . 11

A Buzzer Makes an Handy Multivibrator. . . . 12

Radio Frequency for Industrial Heating. . . . 16

SHORTWAVE REVIEW -

Notes From My Diary. . . . 23

New Stations. . . . 23

Shortwave Notes and Observations. . . . 24

THE SERVICE PAGES -

Answers. . . . 26

P.03 - Editorial Notes
Editorial

Right in the midst of a lot of discussion about amplifiers there has been dropped a regular "block buster", full details of which we hope to reveal in next month's issue. Following closely on the heels of statements about "amplifiers beyond reproach", and "perfect direct-coupled amplifiers", a completely new and revolutionary circuit has come to hand. This circuit is so unconventional as to appear absurd, but is actually a definite step in the right direction and full of the most amazing possibilities. In a nutshell, it has been found that output impedance problems are solved if the output of a valve is taken by placing a load on the cathode circuit, instead of plate circuit. Tremendous loss of gain is incurred, but in these modern times this is of little importance, compared to the improved fidelity possible. As an example, an output valve required about twenty volts of signal input for ordinary use, but under the new operating conditions will require a signal input of 150 volts. One application of the scheme is for inter-stage coupling, using a cheap audio transformer, which then gives performance comparable with that of a super-duper high-fidelity one. Practical work with the new circuit has proved highly interesting and results are right up to expectations. Working with an audio transformer which cost 6/6 we have been able to get quality reproduction of a high standard, at the same time obtaining the advantage of low resistance in the grid circuit. This is highly desirable, but hard to achieve with resistance-capacity coupled amplifiers. - A. G. HULL.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1944 10

P.03 - Contents Banner
The Australasian Radio World

Devoted entirely to Technical Radio

and incorporating

All-Wave All-World DX News

Vol. 9 - OCTOBER, 1944 - No. 5

P.03 - Publication Notes
Proprietor - A. G. HULL

Manager - Dudley L. Walter

Secretary - Miss E. M. Vincent

Short-wave Editor - L. J. Keast

For all correspondence: City Office - 243 Elizabeth St., Sydney -  Phone MA2325

Office Hours - Week-days: 10 a.m. - 5 p.m., Saturdays: 10 a.m. - 12 noon

Editorial Office - 117 Reservoir Street, Sydney

Subscription Rates - 6 issues 5/3, 12 issues 10/6, 24 issues £1, Post free to any address

Service Departments - Back Numbers, 1/- ea., post free; Reply-by-mail Queries, 1/- each

Printed by Bridge Printery Pty. Ltd., 117 Reservoir Street, Sydney, N.S.W., for the proprietor of the "Australasian Radio World," 117 Reservoir St., Sydney (Footnote P.28)

P.03 - Contents
CONTENTS:

CONSTRUCTIONAL -

Something Fresh in Amplifiers. . . . 5

"Novochord" is Electronic Piano. . . . 7

Pick-Up Principles and Practice. . . . 13

Cathode-Follower Amplifier Design. . . . 16

Inductance and Capacity Meter. . . . 17

TECHNICAL -

Cathode Follower Output Stage. . . . 11

Iconoscope - The Electron "Gun". . . . 21

SHORTWAVE REVIEW -

Notes of My Diary. . . . 23

Shortwave Notes and Observations. . . . 24

New Stations. . . . 24

THE SERVICE PAGES -

Answers. . . . 26

P.03 - Editorial Notes
Editorial

Frequency modulation is headline news in the papers these days, following on statements which have emanated from Canberra. Following the usual routine, these statements have in due course been denied, and counter-statements have been issued. But where there is smoke you usually find fire, and so people gain the impression that there must be something to this frequency modulation business. The talk about frequency modulation has caught many radio engineers "on the hop", and we have been inundated for the back numbers in which the subject was dealt with, but these are no longer available. We have not had time to get a full story ready for this issue, but we plan to cover the whole subject in detail in next month's issue, including the possibilities which the scheme may open up. We do not under-estimate these possibilities, but at the same time we feel sure that they will take a considerable time to reach fruition and there is not quite as much need for a rush as some of our readers seem to feel. First the war has to be completely cleaned up, then the plans have to be laid, and we cannot imagine that frequency modulation will be a completely established service until at least a couple of years after the cessation of hostilities. In the meantime, radio technicians will have ample time to become thoroughly acquainted with the new technique.


text:
User:Beingiroyal

Vishwa p gudda founder of Being Royal since 2003 known as 2003

title: User:Beingiroyal


text:
Irish/Question Formation

Just as in English, most questions in Irish are formed using special words and constructions. article gives a comprehensive overview of Irish question formation, question words, and other grammatical and syntactical topics related to asking questions in Irish.

The Interrogative Copula
Text

Is and Ta
Text

Question Words
Text

Answering Questions
Text

title: Irish/Question Formation


text:
Talk:Using Wikibooks/How To Edit A Wikibook

Moving Pages Question
I don't see a "move" tab on pages (I do on Wikipedia, but not here). Is this something that won't show up until I have Reviewer rights? The book I'd like to work on (Irish) needs significant reorganization as a first step. Chapka (discuss • contribs) 08:42, 9 June 2020 (UTC)
 * You need to be autoconfirmed here. Please ensure you properly understand the book structure here before you move anything - it is different to Wikipedia. QuiteUnusual (discuss • contribs) 08:51, 9 June 2020 (UTC)

The "Adding Pages" Section
Hi, just wanted to point out that the Adding Pages section of this page doesn't actually explain how to add pages. Heads up! Qucchia (discuss • contribs) 13:46, 29 August 2021 (UTC)


text:
Irish/Shared/Vocabulary List

 Vocabulary gallery

title: Irish/Shared/Vocabulary List


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1944 11

P.03 - Contents Banner
The Australasian Radio World

Devoted entirely to Technical Radio

and incorporating

All-Wave All-World DX News

Vol. 9 - NOVEMBER, 1944 - No. 6

P.03 - Publication Notes
Proprietor - A. G. HULL

Manager - Dudley L. Walter

Secretary - Miss E. M. Vincent

Short-wave Editor - L. J. Keast

For all correspondence: City Office - 243 Elizabeth St., Sydney -  Phone MA2325

Office Hours - Week-days: 10 a.m. - 5 p.m., Saturdays: 10 a.m. - 12 noon

Editorial Office - 117 Reservoir Street, Sydney

Subscription Rates - 6 issues 5/3, 12 issues 10/6, 24 issues £1, Post free to any address

Service Departments - Back Numbers, 1/- ea., post free; Reply-by-mail Queries, 1/- each

Printed by Bridge Printery Pty. Ltd., 117 Reservoir Street, Sydney, N.S.W., for the proprietor of the "Australasian Radio World," 117 Reservoir St., Sydney (Footnote P.36)

P.03 - Contents
CONTENTS:

CONSTRUCTIONAL -

Repairing and Adjusting Vibrators. . . . 22

A Receiver Without Gang. . . . 23

Alignment by Wobbler. . . . 9

Pick-up Principles and Practice. . . . 11

TECHNICAL -

Mutton Good at Amplifiers. . . . 5

Possibilities of Frequency Modulation. . . . 7

Curves - Straight or Bent. . . . 13

Valves in Theory and Practice. . . . 16

Research Into Phase-Changers. . . . 21

The Future for Recordings. . . . 24

SHORTWAVE REVIEW -

Notes from My Diary. . . . 27

New Stations. . . . 27

Shortwave Notes and Observations. . . . 28

Loggings. . . . 31

THE SERVICE PAGES -

Answers. . . . 33

P.03 - Editorial Notes
Editorial

To some outsiders it is difficult to understand the inspiration which motivates the radio enthusiast. Business acquaintances are amazed at the circulation of "Australasian Radio World." They cannot see why it sells so well at a time when radio parts are difficult to obtain, set construction is controlled and, generally, conditions are adverse for the experimenter. At the moment our sales are more than double the figure they were in 1939, and our subscribers number four times as many. What is the reason? You know the reason as well as I do. Radio is interesting. Reading about circuit developments is instructive and enjoyable. With simple equipment and a few "junk" parts it is possible to carry out practical experimenting which has excitement, even thrills for the keen radioman. Routine repairs of broken-down sets is not hum-drum work. In most cases it calls for the skill of the fictional detective, tracking down the trouble by careful analysis of clues which point the way. Sometimes the puzzle is quite baffling and the alert radioman pursues a most enjoyable hunt to locate the culprit component. Considering the practical angles only, the hard-headed realists have long pointed out that you can buy a radio set almost as cheaply as you can build one. But have you ever known anyone to derive so much enjoyment from a factory-built set as he gets from one built with his own hands, adjusted to suit his own taste and inside which he can visualize each component "doing its stuff" as the signal passes from aerial to speaker? The more we think of it, the greater is our faith in the future of the technical radio enthusiast.


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1944 12

P.03 - Contents Banner
The Australasian Radio World

Devoted entirely to Technical Radio

and incorporating

All-Wave All-World DX News

Vol. 9. - DECEMBER, 1944 - No. 7.

P.03 - Publication Notes
Proprietor - A. G. HULL

Manager - Dudley L. Walter

Secretary - Miss E. M. Vincent

Short-wave Editor - L. J. Keast

For all correspondence: City Office - 243 Elizabeth St., Sydney -  Phone MA2325

Office Hours - Week-days: 10 a.m. - 5 p.m., Saturdays: 10 a.m. - 12 noon

Editorial Office - 117 Reservoir Street, Sydney

Subscription Rates - 6 issues 5/3, 12 issues 10/6, 24 issues £1, Post free to any address

Service Departments - Back Numbers, 1/- ea., post free; Reply-by-mail Queries, 1/- each

Printed by Bridge Printery Pty. Ltd., 117 Reservoir Street, Sydney, N.S.W., for the proprietor of the "Australasian Radio World," Elizabeth St., Sydney (Footnote P.36)

P.03 - Contents
CONTENTS:

CONSTRUCTIONAL -

Contest Was Keen. . . . 5

Pick-up Principles. . . . 13

Victorian Championship. . . . 17

TECHNICAL -

Aesthetics of Reproduction. . . . 19

Music While You Work. . . . 26

SHORTWAVE REVIEW -

Shortwave Notes and Observations. . . . 29

Notes From My Diary. . . . 31

New Stations. . . . 33

THE SERVICE PAGES -

Answers. . . . 34

P.03 - Editorial Notes
Editorial

Those of our readers who are enthusiasts on the subject of quality reproduction must be a little bewildered at the moment. We had hardly finished publishing an amplifier circuit "to end all amplifier circuits" when along came the cathode-follower scare. To add to the confusion, then came the results of the Victorian Amplifier Championship, indicating that beam power valves, even with inverse feedback, do not give the practical results which can be calculated for them by theory. Even direct-coupled enthusiasts were disappointed. In fact, it might be said that the Victorian contest puts us all back about fifteen years in our theories. To cap it all, along comes the latest issue of the famous Wireless World from London, with an article by well-known quality exponent H. A. Hartley, who now confesses that high fidelity reproduction is not desirable. The article is so complete in its coverage and so full of interest in every way that we feel bound to reprint it for the benefit of our many readers who are unable to obtain a copy of the English publication. At the same time we feel that some sort of explanation is needed to clarify our policy in these matters. Some letters have been received from irate readers who claim that we seem to be deliberately misleading them by publishing contradictory stories in quick succession. Briefly, our policy at the moment is to present all these theories as they come to hand. We leave it to you to use your own discrimination as to what you decide to follow.


text:
User talk:Chapka

Welcome
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We sent you an e-mail
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MediaWiki message delivery (discuss • contribs) 18:48, 25 September 2020 (UTC)

title: User talk:Chapka


text:
Irish/Reference/Numbers

Counting and using numbers in Irish is more complex than in some other languages. This page explains the different number systems used in Modern Irish and how to use them.

Types of Numbers
Many languages, including English, use different numbering systems for different purposes. English has two: one used for cardinal numbers (one, two three) and one for ordinal numbers (first, second, third).

Irish has not two, but four different numbering systems. They are:

 * Cardinal numbers (maoluimhreacha)
 * Cardinal numbers in Irish are used only when the number is not modifying another noun; for example, when counting.

 * Impersonal numbers (uimhreacha néamhphearsanta)
 * Used as adjectives when the number is modifying something other than people

 * Personal numbers (uimhreacha pearsanta)
 * Used as an adjective when the number is modifying a noun representing a person or people

 * Ordinal numbers (orduimhreacha)
 * Used for indicating order or position, just as in English

Because the impersonal numbers (uimhreacha néamphearsanta) are usually the same as the cardinal numbers (maoluimhreacha), but without the numeral particle "a", these two systems are often lumped together as "cardinal numbers" when they are taught.

Using Numbers
Unlike most Irish adjectives, when a number is used as an adjective in Irish it precedes the noun it modifies.

The Number One
The number one is a special case in Irish.

title: Irish/Reference/Numbers


text:
Planet Earth/5d. Surface Ocean Circulation

An Ill Fated Expedition to the North Pole
Encased in ice, the American ship Jeannette was being crushed, its wooden hull cracking and breaking under the intense cold grip of the frozen ocean. For the past month, the ship had been entrapped in the arctic ice. The crew scrambled as they off-loaded boats onto the flat white barren landscape. They dragged the boats with them, as they watched with horror the splintered remains of the ship sink between the icy canvasses of the frozen Arctic ocean. The expedition was headed toward the North Pole, led by their captain George W. De Long, a United States Navy officer who was on a quest to find passage to the open northern polar sea. His ship sinking beneath the ice, left his crew isolated upon the frozen ocean. De Long took out his captain log book, and listed the location of the sinking ship, 77.25°N, 155°W, before ordering the men to drag the boats and whatever provisions they had remaining across the vast expanse of ice. Once they reached open water, they set their boats into the non-frozen waters and rowed southward. Chief Engineer George Melville, a stoic figure with a long prophetic beard, led one group of survivors. Melville had worked his way up in the Navy, helping to establish the United States Naval Academy, was a veteran of such dangerous Arctic explorations. In 1873, he volunteered to help rescue the survivors of the ill-fated Polaris expedition, an attempt to reach the North Pole. Now trapped in a similar situation George Melville watched as the various boats were tossed on the open water and soon became separated in the night. It was the last time he would see Captain De Long, alive. His small crew on the boat would survive after landing on the shores of the Lena Delta on the northern coast of Siberia. For the next year, Melville searched for De Long, and finally discovered his body, and those of 11 crew men. He also found the captain’s log book that recorded their furthermost approach to the North Pole. Melville wrote of the ill-fated expedition, and the search for the Captain in a book published in 1884. That same year, 1884, the wreckage of their ship was discovered off the coast of Greenland. The ship despite sinking in the ice north of Siberia, had somehow traveled across the Arctic ocean carried by the polar ocean currents to Southern Greenland, thousands of miles away. The long voyage of this wreckage, sparked an idea for another attempt to reach the North Pole by the Norwegian explorer Fridtjof Nansen to purposely sail a steamship into the ice, and let the ice carry the vessel as close as possible to the North Pole. Once the trapped ship reached the furthermost distance north in the ice, a dog sled team could disembark from the ice encased ship, and travel the remaining miles over frozen sea ice to reach the northernmost point on Planet Earth. It was a daring plan, that required knowledge of the motion of ocean currents and sea ice in the high arctic. The steamship Fram sailed from Norway following the coast of northern Siberia, then looped back heading northward until it encountered the ice. For three years the ship was carried on its northward then westward journey trapped and encased in ice, when it reached its most northern point on March 14 1895, Fridtjof Nansen and Hjalmar Johansen disembarked from the ice trapped ship, and headed even further north by dog sled. Nansen would record a northern latitude of 86°13.6′ North on his sextant, before turning back, unable to reach the north pole at 90° N. Over the next year the two men traveled southward over the sea ice, and miraculously both men would survive the journey. The ice trapped steamship and its crew was released from the ice and was able to sail back successfully to Norway. No crew member died with the attempt, and despite not reaching the North Pole, the expedition was viewed as an amazing success. A marine zoologist by training, Nansen returned home and dedicated himself to studying the ocean.

How Ocean Currents Move Across Earth
Fridtjof Nansen remained puzzled how ocean currents move across Earth. He was particularly interested in how icebergs and stranded ships are carried by the ocean. During the expedition, Nansen utilized the Transpolar drift an ocean current that flows from the coast of Siberia westward toward Greenland, driven by a large circular current called the Beaufort Gyre, that encircles the North Pole. In oceanography, a gyre is a large circulating ocean surface current. The Beaufort Gyre spins clockwise around the North Pole, while Earth spins in a counterclockwise direction around the polar axis. Nansen reasoned that the reason the surface of the ocean spins in the opposite direction to the Earth is that unlike the solid earth, the liquid ocean (and the atmospheric gas above) are only loosely attached to the surface of the Earth, the inertia of the Earth’s rotation and drag, causes the liquid to trail or lag behind the motion of the solid Earth. When Nansen’s ship was trapped in the sea ice, the Earth rotated around below the ship, while the liquid ocean, carrying the frozen sea ice and trapped ship appeared to resisted this motion, and hence the coast of Greenland was brought toward the ship, as the solid Earth rotated below it. However, Nansen realized that this was not true, since the ocean and solid earth travel around the axis at nearly the same constant velocity and same inertia. The ice and ocean currents should rotate in-sync with the rotating Earth. During the expedition, Nansen noticed that ice drifted at an angle between 20° to 40° to the right of the prevailing wind direction, he suspected that the ocean currents were influenced by prevailing wind directions instead. Nansen contacted Professor Vilhelm Bjerknes at the University of Uppsala, who was studying fluid dynamics. Bjerknes thought the ocean currents were largely controlled by the Coriolis force arising from the motion of the Earth, but suggested that his brightest student, Vagn Walfrid Ekman undertake the study for his doctoral research. Ekman was the opposite of the rugged Arctic explorer Nansen. Ekman was studious with thick eye glasses and a petite gentle frame. He was more comfortable with mathematic equations and played the piano and sung in a local choir.

Fluid dynamic experiments carried out with rotating bowls of water at a constant velocity showed that spinning the bowl (with zero acceleration), there was a stabilizing effect when drops of colored dye were added to the water from above. This is because the point or location the dye was added to a spinning bowl of water had the same speed and same inertia as the spinning bowl beneath it. In fact, the color from the dye was observed to form a narrow column, and not rotate in relation to the spinning bowl beneath. This seemed to suggest that the Arctic exploring feat of Nansen was an impossibility. However, if dye was added to the spinning bowl of water from the side, the dye would quickly spiral due to the Coriolis effect, as the dye was moving across different radii, and hence its velocity was changing due to this horizontal motion.

Ekman suspected that in the open ocean there were various forces working to change the velocity or speed of the ocean water that would destabilize the water and result in its motion. Ekman defined two boundaries, known as Ekman Layers, the first of which is the ocean floor. The ocean floor is not flat, but has a complex topography, this boundary is the most rigid as it is under the most pressure from water above. The second Ekman Layer is the ocean’s surface. Here the ocean is affected by blowing wind, and is under the least amount of pressure. The prevailing wind would be governed by geostrophic flow, that is affected by a balance between atmospheric pressure gradients, and the Coriolis force; these geostrophic winds tend to travel parallel to an air pressure gradient. Wind would only affect the uppermost portion of the ocean, maybe only to depths of 10 meters. This pressure gradient between the two Ekman Layers of the ocean results in changes in velocity between each layer, resulting a shearing of the liquid ocean, as the upper part is influenced by the wind direction and the lower part is influenced by the rotating Earth. Using mathematical formulas, Ekman demonstrated that this motion would result in a spin or spiral motion within the ocean, known as the Ekman Spiral.

At the surface of the ocean, the direction of horizontal motion would be greatest, because of the influence of geostrophic winds on the ocean surface. The geostrophic winds would drive the ocean water below them to flow perpendicular to the Coriolis direction, however, since the water is not influenced by the air pressure gradient, they will be more affected by the Coriolis direction resulting in a current that is at an angle between 20° to 40° to the right (in the Northern Hemisphere) of the prevailing wind direction. The Ekman Spiral, and the mathematics that Ekman developed allowed a profound understanding of the motion of ocean currents. The Ekman Spiral has several important implications. First is that surface, or near surface ocean waters move the quickest, while deep ocean waters are much less mobile, and are more permanently fixed to the ocean floor. Oceanographers describe the motion of ocean water circulation across the Earth into two very different patterns. Those of surface ocean circulation are much more mobile, with surface ocean water circulating across the planet very quickly (a few months to several years), while deep ocean circulation is much slower, with long term patterns of deep-water circulation lasting hundreds or thousands of years. The Ekman Spiral also demonstrated how Nansen’s daring expedition was able to be successful, since the ship was trapped in sea ice at the surface, it was affected by the prevailing geostrophic easterly winds that blow across the Transpolar drift, in addition to the Coriolis Effect spinning the Beaufort Gyre in a clock-wise direction. This resulted in surface ocean waters and sea ice to travel at an 20° to 40° angle to the prevailing wind direction, and resulted in Nansen’s near successful attempt at reaching the north pole.

Upwelling and Downwelling
Ekman’s spiral is useful in understanding how ocean water can move vertically through the water column, especially within ocean water near coastlines along the continental margins. This upwelling and downwelling occurs when wind directions drive ocean currents either toward or away from the coastline. If the prevailing wind is blowing and results in surface ocean currents that move from the ocean toward the land and these surface ocean currents are perpendicular to the coastline, the surface ocean waters will result in a downwelling of ocean waters, as the ocean water is pushed deeper when it reaches the coast. However, when the prevailing wind is blowing from land out across the ocean and the surface ocean current is perpendicular to the coastline in the opposite direction, upwelling occurs, as the surface ocean water will be pushed away from coastline, bringing up deeper ocean water to the surface. Often however, the prevailing surface ocean currents are not simply perpendicular to the coastline, resulting in a flow of water called a Longshore Current. Longshore currents depend on a prevailing oblique wind direction that transports water and sediments, like beach sand along the coast parallel to the shoreline. When longshore currents converge in opposite directions, or there is a break in the waves, a Rip Current will form that moves surface ocean water away from the shore and out to sea. Rip currents are dangerous to swimmers, since the strong currents will carry unsuspecting swimmers away from the shore. It is important to note that the upwelling and downwelling of ocean water resulting from Ekman’s research is relatively shallow across the entire ocean, and occurs mostly along the shallow coastlines of islands and continents. The deepest ocean waters in the Abyssal Zone require a different mechanism to raise or lower these deep ocean waters to the surface, which will be discussed later. However, the discoveries and mathematical models of Ekman are important in understanding surface ocean circulation around the world.

Surface Ocean Circulation
Surface ocean circulation in the Northern Hemisphere will spin toward the right in a clockwise direction, while in the Southern Hemisphere surface ocean currents will spin toward the left in a counter-clockwise direction. One of the most well-known surface ocean currents is the Gulf Stream, which extends from the West Indies, through the Caribbean, north along the eastern Coast of the United States and Canada, and brings warm equatorial ocean waters to the British Isles and Europe. The Gulf Stream is part of the larger North Atlantic Gyre, which rotates in a large clock-wise direction in the Northern Atlantic Ocean. The Gulf Stream brings warm ocean waters to the shores of Western Europe, resulting in a warmer climate for these regions. The Canary Current, which travels southward from Spain off the coast of Africa, results in colder surface ocean waters traveling toward the equator, where currents meet the North Equatorial Current completing the full circuit of the North Atlantic Gyre. In the Southern Atlantic Ocean, the surface ocean current rotates in a counter-clockwise direction. Traveling west along the southern equatorial current, then south along the coast of Brazil, east crossing the South Atlantic, and then north along the coast of the Namibian Coast, in a counter-clockwise circuit, as the Southern Atlantic Gyre. The center of both the Northern and Southern Atlantic Gyre, surface ocean currents remain fairly stagnant. Early sailors refer to the center of the Northern Atlantic Gyre as the Sargasso Sea, named because of the abundance of brown seaweed of the genus Sargassum floating in the fairly stagnant ocean waters. Today these regions of the North and South Atlantic Ocean are known by a much more ominous name, the garbage patch. Plastics and other garbage dumped into the oceans accumulate in these regions of the ocean, where they form large floating masses of microplastic polyethylene and polypropylene which make up common household items which have been dumped and carried out into the oceans. Between the Northern and Southern Atlantic Gyre is a region that sailors historically referred to as the doldrums, which is found along the equatorial latitudes of the Atlantic Ocean. Here surface ocean waters are not as strongly affected by the Coriolis force, because the ocean water is carried in the same direction as the rotation of the Earth. This results in what is known as the Equatorial Counter-Current. The equatorial counter-current carries surface ocean waters from the west to the east, in the opposite direction as the easterly trade winds that carry sailors from the east toward the west near the equator. The equatorial counter-current is a result of the Intertropical Convergence Zone (ITCZ) winds which form a low-pressure converging zone as atmospheric air rises due to the increase in heat from the sun in these warm waters.

Sailing ships avoid these regions, as they can significantly slow the progression of sailing ships dependent on surface ocean currents and prevailing winds. Sailors traveling from Europe to North America follow the easterly trade winds north of this zone, while returning sailors traveling back to Europe following the westerly trade winds of the Gulf Stream, crossing the Northern Atlantic Ocean more north than their voyage to North America. This resulted in early trade routes across the Atlantic following the coast from the West Indies north toward New York, resulting in goods being transported from the south to the north along the Eastern ports of North America. While the Caribbean Islands were some of the first places European and African traders arrived at in the North Hemisphere after traversing the Atlantic Ocean. Ships today are less influenced by surface ocean currents and prevailing winds with engines that drive propellers under the ships. However, surface ocean currents do determine the flow of lost cargo from ships, and are useful for rescuing stranded sailors who are at the mercy of the ocean and its currents.

The Pacific Ocean mirrors the surface ocean currents of the Atlantic, but is at a much larger scale. Similarly, there are two large gyre. In the North Pacific, the North Pacific Gyre is a flow of surface ocean currents that follows a clock-wise direction. With warm equatorial waters moving northward along the Asian coasts, into Korea and Japan, the Kuroshio Current. This current, like the Gulf Stream is a warm current moving northward, the current passes over the North Pacific, before flowing toward the south along the Western Pacific Coast of North America, where it is known as the Californian current. This motion of warm equatorial water across the North Pacific results in a similar warming along the northern coastline of North America. It also moves floating debris from the coast of Japan to the Pacific Northwest coasts of Canada and the United States. Although because the Pacific Ocean is larger than the Atlantic Ocean, the ocean water has cooled slightly. Nevertheless, this Pacific Northwest surface ocean water is warmer than would normally be expected at such high latitudes. For example, the average annual temperature in Vancouver, Canada at latitude 49.30° North is 11.0 °C, while Halifax, Canada (along the North Atlantic Coast) at latitude 44.65° North is just 6.5 °C, despite its more comparatively southern latitude. These warm surface ocean currents may have left much of the North Pacific Coast of North America ice free during past Ice Ages, when large ice sheets covered the interior of Canada. The now cooling waters move southward along the Pacific Coast of the United States resulting in cooler, more temperate climates for Southern California, than would be expected given the more southern latitude of cities like Los Angeles. Surface Ocean Currents have a profound effect on local climates.

The South Pacific Gyre spins in the opposite direction as to the north, in a counter-clockwise direction. This results in warm equatorial ocean surface currents to flow into South Australia and off the coast of New Zealand, bringing warm water to these regions. The East Australian current, like the Kuroshio and Gulf Stream warms these regions, including the Great Barrier Reef southward into Sydney Harbor. The surface ocean circulation then transverses the South Pacific, but cools as it is pushed along the Antarctic Circumpolar current, the Peru current brings cold waters along the western coast of South America, clear up toward the Galápagos Islands. Despite the equatorial latitude, the waters off the Galápagos Islands are relatively cool compared to other equatorial ocean waters due to this cooler Peru current. Penguins occupy the rocky shore line of the islands, at their most northward range. Just like in the Atlantic Ocean, a large Equatorial Counter Current flows toward the east within the ITCZ, producing doldrums in the Pacific as well.

The Indian Ocean, unlike the Atlantic and Pacific Oceans is mostly south of the equator, and hence only has one large surface ocean gyre that rotates in the counter-clockwise direction. There is an Equatorial Counter-Current that flows toward the east off the southern coast of India, as a result of the ITCZ. This zone shifts northward over the Indian Subcontinent annually, producing the Indian Monsoonal rains each year. East Africa and Madagascar enjoy warmer tropical ocean currents similar to the Gulf Stream, Kuroshio, and East Australian Currents, making these regions also susceptible to typhoons and hurricanes. The last surface ocean current is by far one of the most important: the Antarctic Circumpolar Current, also known as the West Wind Drift, which encircles the coast of Antarctica. Most of the currents we have discussed are a product of the rotation of the Earth, as well as the arrangement of the continents, which block the motion of the ocean toward the east, resulting in the many gyre discussed above. The Antarctic Circumpolar Current flows toward the east, and because there is no major landmass in its path, continues this flow in perpetuity, always encircling the coast of Antarctic. These ocean waters remain cold, bitterly so compared to other ocean currents, because surface ocean currents do not loop toward warmer equatorial regions of the planet. The advent of the Antarctic Circumpolar Current occurred at the beginning of the Oligocene Epoch, 33.9 million years ago, when the Drake Passage that separates South America and Antarctic opened, allowing ocean currents to flow between the two continents, and preventing cold Antarctic ocean waters to be conducted northward. Instead, from this point onward, the Antarctic Circumpolar Current significantly cooled Antarctica, resulting in massive ice sheets to form on the continent, and making it the inhospitably cold place that it is today. The Antarctic Circumpolar Current had a global effect on the planet, resulting in cold global temperatures that led to the beginning of the Great Ice Ages. Millions of years prior to this event, a no longer existing Global Equatorial Current existed, which passed between North and South America, and extending through the ancient seaway known as the Tethys that separated Africa and Europe and covered the Middle East. This current at the equator, resulting in some of the warmest global climates for Earth during the Eocene Epoch around 50 million years ago. Surface ocean currents have a major effect on regional and global climate, because they are a way, through convection, to bring warm and cold ocean water to different parts of the Earth’s surface.


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Planet Earth/5e. Deep Ocean Circulation

Density, Salinity and Temperature of the Ocean
Density is a measure of the substance’s mass per unit volume, or how compacted or dense a substance is. Specific density is a measure of whether a substance will float or sink relative to pure water, which has a specific density of 1. Liquids with a specific density less than 1 will float, while liquids with a specific density of more than 1 will sink in a glass of pure water. Ocean water, because it contains a mixture of salts and dissolved particles averages a specific density between 1.020 to 1.029. Density in ocean water is measured using a hydrometer, which is a glass tube with a standard weight attached to a scale that indicates how far the weight sinks in the fluid. If you were to mix ocean water and freshwater, the two would likely mix, making it difficult to determine whether one floats above another. The greater density difference between fluids, the more likely you can get them to stack on top of each other, by floating the less dense fluid on top of the denser fluid. However, if you try to stack the denser fluid on top of a less dense fluid, the two fluids simply mix. A column of fluids of different densities is said to be stratified, strata means layers, so a stratified ocean is an ocean that is divided into unique layers based on differences in densities.

The density of water is not only related to how much salt is dissolved in the water, but also the water’s temperature. The colder the water, the denser it becomes, although between 4° C to 0° C near the freezing point water becomes less dense as it freezes to ice. The gradient between density and salinity of ocean water is called the halocline. In a vertical profile of the ocean, salinity increases with depth, because salty water is denser and will sink. The gradient between density and temperature of ocean water is called the thermocline. In a vertical profile of the ocean, temperature decreases with depth, as colder water (above 4°C) is denser and will sink. The densest ocean water is both cold and salty, while the least dense ocean water is both hot and fresh. The gradient of density with depth is referred to as the pycnocline. Pycnos in ancient Greek means dense. The pycnocline is a graph showing density with depth of ocean water. If the ocean is stratified into layers of different densities, the graph will show a slope with steps at each layer of increasing density. However, if the ocean is well mixed, the pycnocline will be a straight line vertical of equal density with depth. In the previous sections, surface ocean currents and upwelling and downwelling are influenced by geostrophic winds, and surface processes that result in shallow movement of the ocean waters. However, Ekman’s research also showed that deep ocean water, deeper than 100 meters will remain less mobile, and will not be influenced by these forces that work only on the surface of the ocean. Deep ocean water moves very slowly, so slowly that oceanographers debate what the rate of movement of this deep ocean water truly is as it moves around the Earth.

Deep ocean water circulation of the planet is a slow and gentle process that involves most of the total volume of the oceans, and is a consequence of dynamic changes in ocean water density with depth. Such changes in density result in a mixing of surface and deep ocean waters.

Stratified Water
How do oceans or for that matter any large body of water on Earth become stratified into different layers of density?

Imagine a large lake, which serves as a reservoir of water with inflowing rivers of fresh salt-free water. The flux of incoming freshwater into the lake from the surrounding rivers decreases in the late summer, but increases in the late winter and early spring from run off or the rainy seasons. During the summer the hot sun heats the top layers of the lake resulting in evaporation, and the underlying layers of water become saltier, but remain warm. Over time such a lake will become stratified into different layers of density. In the summer, the surface water will become salty, but warmer, allowing it to float over the denser water below, however, as the fall temperatures drop, the salty water will increase in density. During the spring an influx of less dense freshwater from the rivers will float over this salty and colder water already in the lake. This adds a new layer of less dense freshwater, and stacks the water on top. Over time, the lake will become heavily stratified into cold/salty dense layers remaining deep in the lake, while warm/fresh less dense water remain at the top with each input of freshwater. What process can cause the two layers to mix? If during the winter months the lake is covered in ice, the top layer of water will become both cold and salty. The salt originates from the fact that as ice forms on the top of the lake, the ice will contain no salts, leaving the layers just below the ice slightly saltier, and very cold. Ice coverage on the lake will cause this salty/cold dense water to lay on top of warm/fresh less dense water, which will ultimately cause the water at the surface to sink, and the deep water to rise. An ice-covered body of water contains a better mixture of waters compared to ice-free bodies of water. As a result, bodies of water in cold regions of Earth are less stratified than waters in warm tropical regions. Another thing that can happen to the lake is if the deep water is somehow warmed. This can occur when a volcano or magma heats the bottom waters. When these dense deep waters are heated, they become less dense and rise, this is likely what happened in the Lake Nyos disaster in Cameroon Africa, when deep waters bubbled up releasing massive amounts of carbon dioxide gas killing many people.

Measurements of the pycnocline in various lakes around the world demonstrate that colder lakes covered in ice during the winter are better mixed than warmer lakes, which remain ice free. The same processes of mixing deep waters with surface waters can be applied to the entire ocean, which is more complex since the Worlds Ocean is more interconnected and spans the entire Earth’s surface. Oceanographers have mapped out differences in annual temperatures and salinity to help to understand this complex process. Annual surface temperatures measured across the entire ocean show that the warmest waters are found along the equator, with the coldest waters found near the poles. However, surface salinity measured across the entire ocean shows that the saltiest surface waters are found within the large ocean gyres, such as the North Atlantic and South Atlantic gyres, which are some of the saltiest regions of the open ocean. This is because these regions of the ocean are more stagnant, as well as being in drier regions that receive less rainfall. The ITCZ around the equator contributes massive amounts of freshwater from rain, and limits evaporation along the equator. Large confided bodies of ocean water surrounded by land, like the Mediterranean and Red Seas, are some of the most saline regions of the ocean. Some of the least salty regions of the ocean are found near where there is a large input into the ocean of freshwater from rivers, particularly in Southeastern Asia. Regions near the poles also get input of freshwater from melt waters. Sea ice which expands during the winter months in polar regions of the Arctic and Antarctic Oceans is important for the mixing of surface and deep ocean waters. If these waters are already salty from evaporation, mixing can be enhanced. In the North Atlantic the salty surface ocean waters trapped in the North Atlantic gyre are pushed northward toward Greenland with the Gulf Stream currents. If these salty warmer waters are subsequently cooled and covered in sea ice, these waters will sink, resulting in a mixing of surface and deep waters in the North Atlantic Ocean. This drives what is called the Thermohaline circulation of deep ocean waters.

Thermohaline Ocean Circulation of Deep Ocean Waters
The Thermohaline circulation is a broad deep water circulation of the entirety of the world’s ocean, although the precise process of this motion is highly debated among oceanographers. The North Atlantic serves as the region of sinking cold salty water, resulting from salty water in the Atlantic pushed northward, and subjected to coverage of sea ice, especially during the winter months in the Northern Hemisphere. This sinking cold salty ocean water churns the ocean over in the North Atlantic and helps to drive the Gulf Stream, pulling more warm salty waters northward to cool and subsequently sink. The North Atlantic is the least stratified region in the worlds ocean, resulting in well-mixed waters that are enriched in oxygen. Ice core from Greenland records a period of time 12,000 years ago, when the Thermohaline circulation may have been altered dramatically. This period of time is called the Younger Dryas event, because sediments in lakes record the return of pollen of the cold-adapted Dryas arctic flower, which prefers colder climates. The flower grew across much of Northern Europe and Greenland during the last Ice Age up to about 14,000 years ago, when the flower disappeared from these regions as the climate warmed. However, the flower’s pollen returns in the sediments of lakes around 12,000 years ago, signaling a return of cold climates for several hundred years, before again disappearing from these regions. This episode of colder climates in the North Atlantic is hypothesized to be a result of the thermohaline circulation being altered by an influx of freshwater from land. The idea holds that massive amounts of freshwater flooded into the North Atlantic, particularly from the Labrador Sea and Straits of Lawrence, which drained the great ice sheets that covered the Great Lakes and much of Canada. This influx of freshwater resulted in the North Atlantic Ocean becoming more stratified, and resulted in weakening Gulf Stream, with less warm ocean water reaching Northern Europe. This resulted in colder climates to prevail, until the melt of the great ice sheets ended, at which time the Thermohaline circulation resumed, resulting in warmer climates in Northern Europe again. The thermohaline circulation is often depicted as a ribbon of flow that involves the entire world’s ocean, but oceanographers debate how this circulation pattern works in reality on a global scale. Recent research suggests that the deep ocean waters that encircle Antarctica are pulled up as a result of this churning in the North Atlantic. These Southern Ocean waters are warmest during December/January and rise with the warming temperatures, pulled by the North Atlantic which is at its coldest and saltiest levels during these months. In July/August, the North Atlantic Ocean returns to its warmest levels, while the ocean waters around Antarctica are at their coldest and covered by sea ice. Polynyas form in the sea ice around Antarctica, which are regions of thin ice mix with open water which are thinner than expected for the given temperature, because these regions frequently contain saltier water. This results in the cold/salty water to sink deeper around the coast of Antarctica in July/August. Like a teeter-totter, deep ocean water circulating around Antarctica rises and falls each year with the seasons. These Antarctic Bottom Waters are well mixed, and enriched in oxygen and nitrogen. Sea ice is of vital importance in the mixing of the World’s Oceans, and life has adapted to the annual rise and fall of deep ocean waters in these polar regions. When deeper ocean waters rise in these polar regions, they bring up nitrogen which benefits phytoplankton growing in the upper photic zone. Large blooms of phytoplankton occur during the summer months, which attract krill and fish that feed on the phytoplankton. These schools of fish and krill prosper in the oxygen enriched cold waters, and feed migrating baleen whales, which feed on the krill using baleen to filter them out of the water. The largest animal on Planet Earth, the blue whale (Balaenoptera musculus) evolved to exploit the deep ocean circulation patterns that have resulted from large portions of the ocean being covered in sea ice.

Deep Ocean Water Mixing Without Sea Ice
There have been periods of time that Earth’s ocean remained ice free, particularly during periods of enriched carbon dioxide in the atmosphere. Deep ocean water mixing without sea ice formation is possible, and occurs when salty water from warm seas that are confined and subjected to enhanced evaporation enter colder open ocean waters. An example of where this happens is near the Straits of Gibraltar where the salty warm waters of the Mediterranean enter into the colder Atlantic Ocean. Heat diffuses faster than salt, and the relatively faster transfer of heat compared to salt results in the salty water cooling more quickly than the salt can disperse, and hence becomes unstable near the surface of the ocean. This salty/cold water is denser and sinks, forming “salt fingers,” which are a mix of deep and surface waters churning the waters vertically. These regions are enriched in nitrogen, phosphorus, as well as being fairly well oxygenated ocean waters. During Earth’s long history, such regions where responsible for biologically rich ocean life, despite periods of time when the oceans remained ice free year-round. One example of this is found in the rocks of Eastern Utah. During the Pennsylvanian and Permian Periods about 270 million years ago, a land-restricted sea existed in present day Moab, which was extremely salty, but opened out into the larger open ocean to the northwest. The influx of salty water from this sea resulted in a well-mixed ocean despite the much warmer climate of the time. Fossils are found abundantly in marine rocks of this age, as well as thick deposits of phosphorus mined for agricultural fertilizers.

The Danger of Highly Stratified Oceans
If the Earth’s oceans remain ice-free year-round, and there is no influx of salty surface waters from land-restricted seas, like the Mediterranean Sea, then the oceans can quickly become highly stratified. A highly stratified ocean means that deep and surface ocean waters never mix, and oxygen levels become highly restricted to only the surface of the ocean. Such periods of time happened on Earth, particularly during the Mesozoic Era, when dinosaurs roamed a much warmer Earth. These oceans are prone to anoxia, the absence of oxygen, which results in “dead zones” where fish and other animals that need oxygen for respiration perish. An example of ocean water that is susceptible to anoxia is the Gulf of Mexico. During the heat of the late summer, the surface waters in the Gulf of Mexico evaporate resulting in salty surface waters, which sink as winter begins, but remains ice-free. The spring brings large amounts of freshwater from the Mississippi River, which floats on top of the denser ocean water, resulting in a highly stratified ocean. Deep ocean waters in the Gulf of Mexico often lack oxygen because they cannot mix with the surface ocean water (and oxygen atmosphere), and these deep anoxic waters remained locked deep in the basin of the Gulf of Mexico, with the annual influx of spring freshwater and evaporation in late summer warm temperatures.

Catastrophic Mixing of Deep and Surface Ocean Waters
In 1961, James P. Kennett raced across the mountainous landscape of the South Island of New Zealand on a motorcycle on a mission. He was searching for rocks. Ever since he was a child growing up in Wellington, New Zealand, Kennett was collecting rocks, shells and fossils from the beaches and mountains of New Zealand. At 18 he went off to college, having learned all he could about the field of geology from books, but since the subject was not offered at his local school he was eager to learn more at the university. Once enrolled in college classes, he begun working in the geology laboratory at the age of 18. Unlike a biology or chemistry lab, a geology lab is a messy dirty place, where rocks are sliced and cut on saws; boxes of heavy rocks collect dust in cases and drawers; lab coats and beakers are replaced with rock grinders, hammers and chisels. Kennett became interested in tiny marine fossils known as foraminifera, which are studied from either sliced or grounding up rocks. Foraminifera are single celled organisms that live on the ocean floor by feeding on organic detritus that sinks down from the photic zone. They form their protective outer skeleton or shell (test) from calcium carbonate. As common fossils, these tiny fossils accumulate thick deposits on the ocean floor that form marine limestones. Limestones such as those used to build the Pyramids in Giza are actually filled with fossils of these single celled animals. Each rock sample could yield thousands of these tiny fossils, and reveal important clues about the ocean in the past, such as temperature, salinity, acidity, and water depth over long periods of time. As Kennett zoomed down the winding roads of New Zealand, he was on a quest to collect marine deposited rocks that bracket the time of the major climate transition that led to the formation of the great ice sheets in Antarctica. With its close proximity to Antarctica, New Zealand was a good place to study this changing climate, and its effects on the ocean in the ancient marine rocks that now eroded out of the mountains. Kennett was young, and not yet even a graduate student, yet his experiences in the lab made him see the world completely differently. He was eager for his own research, and spent his days hunting new rocks from new periods of time documenting the expansion of the Antarctic sea ice during the late Miocene Epoch. His enthusiasm got the attention of his mentors and instructors and was invited to join the crew of the Victoria University of Wellington Antarctic Expedition in 1962–1963. The expedition was to map the frozen Transantarctic Mountain range south of the Ross Sea and collect rock samples. For Kennett the expedition changed his life, but he continued to document how changes in the ocean over millions of years resulted in an inhospitable cold climate for Antarctic that he experienced firsthand. In 1966 Kennett and his wife moved to the United States, as a pioneer of a new field of research, paleoceanography, a word he coined for the study of ancient oceans. Kennett was excited over the new research coming from sediment cores that were being drilled offshore. These rock cores contained detailed records of tiny fossil foraminifera spanning millions of years, which unlocked the ancient record of the ocean at each location. In the 1970s, Kennett began working with Sir Nicholas Shackleton, the great-nephew of the Antarctic Explorer Ernest Shackleton. Both were focused on a better understanding of the development of the Antarctic Circumpolar Current and how it had resulted in the freezing of the Antarctic Continent, over the last 40 million years. Like Kennett, Shackleton also studied ocean floor sediments, measuring oxygen isotopes of the tiny foraminifera to infer ancient ocean floor temperatures from the past, using a scientific method developed by Harold Urey in the 1940s. Getting samples drilled off the shore of Antarctica was a challenge affair, but unlike the individual rock samples collected while traveling around New Zealand on motorcycle, a drilled core reveals a more complete record of the sediments laid down over millions of years on the ocean floor. In the 1980s, both men became involved in the JOIDES Resolution drilling program, funded by the United States National Science Foundation, which also funds Antarctic exploration for the United States Government. The drilling program successfully drilled through millions of years of worth of sediment on the ocean floor, retrieving cores that would unlock a 90-million-year long history of ocean floor sedimentation off the coast of Antarctica.

The team was driven as much in seeking to understand the record of the more recent glaciation of Antarctica, as they were in finding the deep layer in the ocean core, that represented the moment when large dinosaurs became extinct. As an expert in foraminifera, Kennett and his colleague Lowell Stott, discovered a point in the recovered sediment core, where the foraminifera underwent a dramatic change. The large healthy foraminifera suddenly disappear in the core, replaced by a reddish mud, nearly absent of foraminifera. This layer also did not correspond with the extinction event that killed off the dinosaurs, but millions of years later at the end of the Paleocene Epoch. Isotopes of oxygen from the sediment indicated that the ocean floor became very warm at this point in time. Kennett and Stott wrote a quick paper describing this catastrophic warming of the deep ocean waters around 56 million years ago near Antarctica in 1991, but soon other scientists observed the same features in rocks and core from around the world. In Luxor, Egypt, from the same limestone rocks that were used to build the pyramids, geologists observed the same extinction event in rocks dated to 56 million years old and in Northern Wyoming geologists described a global warming event recorded in the Bighorn Basin of the same time affecting the mammals and plants. Something happened 56 million years to dramatically warm the deep ocean waters. The event was named the PETM (Paleocene-Eocene Thermal Maximum). In the 30 years since the publication by Kennett and Stott, oceanographers have come to the dramatic realization that there can be periods of time when there is catastrophic mixing of deep and surface ocean waters.

The theory goes like this; 56 million years ago, the Arctic Ocean was only narrowly connected to the North Atlantic. The climate was much warmer today, so warm that the Arctic Ocean remained ice free throughout the year, despite the winter months being dark with the short days due to the high latitude at the North Pole. Rivers would drain into the Arctic Ocean during the spring, bringing freshwater. Since the climate was relatively cold, given its geography, evaporation was minimal. The yearly cycle of freshwater would stack on the colder saltier water each year, resulting in a highly stratified body of water. An example of this type of highly stratified body of water today is the Black Sea, but this was on a much larger scale. Each year the North Pole would pass through long summer days, with plenty of sunlight for photosynthesizing phytoplankton, then very short winter days, with little to no sunlight. Each year these blooms of algae and other photosynthesizing organisms would accumulate on the stratified deep ocean seafloor in the Arctic Ocean. Scavenging bacteria would convert this organic matter into methane, which would be trapped on the cold sea floor. This was a ticking bomb.

Around 56 million years ago, a massive set of underwater volcanic eruptions exploded on the ocean floor around present day Iceland and north into the Arctic Ocean. Warming deep ocean water caused these waters to rise, as warm water is less dense. Methane also undergoes sublimation at warmer temperatures. Sublimation is the transition of a substance directly from a solid to a gas phase. This methane gas bubbled up from the deep ocean floor of the Arctic Ocean, releasing massive amounts of methane into the atmosphere, a strong greenhouse gas. Very quickly the atmosphere became enriched in carbon dioxide as the methane reacted to the oxygen in the atmosphere. Suddenly the global climate became hotter and hotter, and the oceans warmed further. This run-away global warming event began to turn the global ocean acidic, killing off most of the tiny carbonate-shelled animals Kennett has spent his life studying.

Such inversions of the ocean, where the deep ocean waters rise up to the surface, appears to have resulted in widespread anoxia (dead zones), methane release, and major extinctions of marine life due to acidic ocean waters. Such deep-water inversion events can be a consequence of run-away global warming, and the destabilization of the vast amounts of solid methane stored on the ocean floor, and often triggered by massive volcanic events. The heating of deep ocean water, results in the water rising to the surface, which can profoundly affect Earth over short spans of time. The current thermohaline circulation of the World’s Ocean keeps this from happening today (by moving surface ocean water downward in the North Atlantic), but many oceanographers worry about recent anthropogenic global warming, which could result in another inversion of the ocean, with deep ocean water rising to the surface. Comparable to the short horror story, The Call of Cthulhu by Lovecraft, the deep ocean is a frightful mysterious place, that in a sense, could destroy the world if it so wished.

title: Planet Earth/5e. Deep Ocean Circulation


text:
Talk:QEMU/QEMU Hello World: Installing QEMU and getting it up and running

Updating dead links.
Some links are dead, it would be nice if someone updated them. Sistemx (discuss • contribs) 16:53, 9 June 2020 (UTC)


text:
User:Rdhill734455/sandbox

About This Guide
This is the Eric 6 User's Guide. Its goal is help users learn about Eric 6, an integrated development environment (IDE) for Python. It contains detailed information about Eric’s main features, tools and benefits and demonstrates them through some typical use-cases.

The guide will probably be most useful to those with some Python experience who are new, occasional or basic users of Eric. Although it may turn into it, the guide is not currently intended to be comprehensive documentation of Eric’s every feature; rather, it focuses on the most popular, useful and powerful ones. It supplements the information available in the Technical Report prepared by Pietro Moras.

The Eric 6 User’s Guide is under development. It is being built by a group of grateful Eric users. You can help by joining in. There are several ways to do that. You can join WikiBooks as a writer/editor and contribute your own content.

Organization

 * 1) Getting Started
 * 2) * Installation
 * 3) * Upgrading
 * 4) * Quick Start
 * 5) * UI Tour
 * 6) Eric as a Quick-And-Dirty Editor/Debugger
 * 7) GUI Development
 * 8) Settings
 * 9) Tools

Main Page

WikiBooks Help:Contents

Eric 6 User's Guide/Eric As a Quick-And-Dirty Python Editor

Scenario
You want to import some data into a database. To do so, you need to manipulate some of the text for consistency, turning text like this:
 * Province/State,Country/Region,Last Update,Confirmed,Deaths,Recovered
 * Anhui,Mainland China,1/22/2020 17:00,1,,
 * Beijing,Mainland China,1/22/2020 17:00,14,,

and this:

 * Province/State,Country/Region,Last Update,Confirmed,Deaths,Recovered,Latitude,Longitude
 * Hubei,Mainland China,2020-03-03T11:43:02,67217,2835,36208,30.9756,112.2707
 * ,South Korea,2020-03-03T09:43:02,5186,28,30,36.0000,128.0000
 * ,Italy,2020-03-03T20:03:06,2502,79,160,43.0000,12.0000
 * ,Iran,2020-03-03T14:23:03,2336,77,291,32.0000,53.0000
 * Guangdong,Mainland China,2020-03-03T10:23:10,1350,7,1101,23.3417,113.4244

and this:

 * FIPS,Admin2,Province_State,Country_Region,Last_Update,Lat,Long_,Confirmed,Deaths,Recovered,Active,Combined_Key
 * 45001,Abbeville,South Carolina,US,2020-04-10 22:54:07,34.22333378,-82.46170658,7,0,0,0,"Abbeville, South Carolina, US"
 * 22001,Acadia,Louisiana,US,2020-04-10 22:54:07,30.295064899999996,-92.41419698,94,4,0,0,"Acadia, Louisiana, US"
 * 51001,Accomack,Virginia,US,2020-04-10 22:54:07,37.76707161,-75.63234615,12,0,0,0,"Accomack, Virginia, US"

into this:
 * Rpt_Date,Confirmed,Deaths,Recovered,Combined_Key
 * "2020-05-18",35,0,0,"Abbeville, South Carolina, US"
 * "2020-05-18",198,12,0,"Acadia, Louisiana, US"
 * "2020-05-18",688,9,0,"Accomack, Virginia, US"
 * "2020-05-18",773,22,0,"Ada, Idaho, US"
 * "2020-05-18",5,0,0,"Adair, Iowa, US"

A perfect project for Python and Eric. This will be a console-only application – no need for classes or a fancy GUI just to clean up some text files.

Background
Suppose you have an interest in Covid-19 data and find the publicly available representations of that data to be too narrow and limiting. You see that news organizations are crediting the Center for Systems Science and Engineering at Johns Hopkins University (JHU CSSE) as the data source. It turns out that JHU makes the data it collects publicly accessible on github: github.com/CSSEGISandData/COVID-19

Suppose further that you have access to a realtional database manaagement system (RDBMS) like MariaDB or Firebird and can work with it using a GUI tool like DBeaver.

Transform Plan
I probably should review the structure of Blender Noob to Pro re flat or deep structure.The recommendation is flat.

So that would be just the main chapter titles

title: User:Rdhill734455/sandbox


text:
User talk:Gorozigg64

Welcome
Welcome to Wikibooks, Gorozigg64!

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--Pi zero (discuss • contribs) 17:19, 9 June 2020 (UTC)

title: User talk:Gorozigg64


text:
User talk:Davidche123

Welcome, Davidche123!

If you have any questions, you can ask in the assistance reading room or possibly contact me personally. —Justin ( koavf ) ❤T☮C☺M☯ 19:36, 9 June 2020 (UTC)

title: User talk:Davidche123


text:
Irish/Unit 1/Lesson 1

Gaeilge | The Irish Language
Irish (Gaeilge) is the traditional language of the island of Ireland, where some version of Irish has been spoken for at least 1,500 years.

Decline and Revival
The Norman and later English invasions of Ireland made first French and then English the language of government, law, and commerce, and by the mid-19th century, English had crowded out Irish in much of the country. This was in part intentional, with English-run government schools teaching only English.

In the late nineteenth century, prominent Irish patriots and nationalists started the Gaelic Revival movement. The Revival encouraged an Irish identity in all aspects of society, but one major focus was the Irish language.

Ulster, Connacht, and Munster
At the time of the Revival, Irish was still spoken as a living, daily language in parts of three of the four provinces of Ireland: Ulster in the north, Connacht in the west, and Munster in the south. These Gaeltachtaí, or Irish-speaking areas, were often isolated, leading to differences in grammar and pronunciation.

Most languages have some regional variation, but language learners usually learn one standardized dialect and accent; English has Received Pronunciation and Chinese has Pǔtōnghuà or Standard Chinese. Irish is unusual in this respect. While there is an official standard of written Irish used in official government documents, it is a compromise between the major dialects, and not a language anyone actually speaks. It is also purely written, and speakers from different parts of Ireland will pronounce some words of "standard" Irish differently. Instead, all three major dialects of Irish have equal stature in Irish culture.

This makes many students of Irish nervous about which dialect of Irish they should learn, and makes the authors of textbooks like this one nervous about which they should teach. But all of us should relax. The dialects are mutually intelligible and many Irish people, especially those who studied Irish at school rather than growing up in a Gaeltacht, speak a mixed dialect.

Which dialect you want to focus on will depend on your reasons for wanting to learn the Irish language, and especially who you want to speak to. We will note in the text when there are major differences between the three major dialects: Ulster, Connacht, and Munster. The most notable differences have to do with pronunciation. To get an idea of the difference between dialects, follow this link to teanglann.ie, a site which provides audio examples for many Irish words in all three major dialects:

Teanglann.ie: "Gaeilge" (Irish)

The vocabulary lists in this textbook will contain links to this site where available. For more information on Irish dialects, please see our reference page on Irish dialects.

The Irish Alphabet: Deceptively Familiar
Languages like Chinese, Arabic, Hebrew or Georgian challenge the learner with an entirely new and unfamiliar alphabet. Irish uses the familiar Latin alphabet used in English, but it brings its own challenges by assigning some familiar letters unfamiliar sounds.

The Letters
There are two important differences between the English and Irish versions of the Latin alphabet.

First, there are eight consonants in the English alphabet that rarely appear in Irish. They are:

These letters were not traditionally part of the Irish language, but many of them have found a place in modern Irish, especially for writing foreign names or loanwords. Some, like "v", are fairly common, while others, like "y", are much rarer, and "k" is all but unknown.

The second difference is that Irish has ten vowels:

As you can see, each of the five standard English vowels has a long variant, which is Irish is indicated by a mark called a síneadh fada.

A vowel with or without a síneadh fada, or fada for short, is considered a different letter in Irish, and adding or removing a fada can completely change the meaning of a word. For example, the Irish word briste is an adjective meaning "broken." The Irish word bríste is a noun, meaning "trousers".

Be careful! Some language learning platforms, including Duolingo, do not mark an answer with a wrong or misplaced fada as incorrect. Don't let that lull you into thinking that the fada is unimportant. Be sure to study the exercises and lessons until you get the fadas correct, just as you would with any other letter.

If you wish, you can learn more about the Irish alphabet on the [Irish/Alphabet | Alphabet] page in the Grammar section. For now, all you need to know is how to generate fadas on any device you plan to use to study Irish. Here is an external link that might be helpful:

Bitesize Irish: Our Fada

Pronouncing the Letters
There is a well-known Irish language author and podcaster named Darach Ó Séaghdha. If you guessed how he pronounced his last name based on English spelling, you'd be unlikely to hit on the correct pronunciation, which sounds something like O'Shea to an English ear. To an English speaker, some Irish words seem to have long strings of silent letters, while "v" sounds sometimes pop up unexpectedly in the middle of a cluster of "m"s, "h"s, and "d"s.

The good news is that Irish pronunciation is not as hard as it looks at first glance. It's more regular and predictable than English, and those letters and clusters that are pronounced very differently from English are easy to recognize once you know what to look for.

Rather than present you with a list to memorize, the goal of Unit One will be to introduce you to a few letters and sounds at a time. Let's start with the words that will make up your first Irish language sentence.

Verb-Subject-Object
In English, most simple sentences follow the word order Subject - Verb - Object:

Jane (subject) reads (verb) a book (object)

Irish instead uses a 'Verb - Subject - Object, or VSO, word order for most sentences:

Reads (verb) Jane (subject) a book (object)

Many Irish sentences follow this basic structure. Now let's learn the words we need to say this sentence in Irish.

The Verb "Léigh"
The Irish verb léigh, meaning "read" or "to read", has two or three sounds, depending on the dialect. The first two are straightforward:

The final two letters, gh, are pronounced differently depending on the dialect:

So in Connacht, we end up with something like the English "lay"; in Ulster, "lay-ee", and Munster "lay-g". This is a good example of dialectical variation, and hopefully you can see from this example that whichever dialect you end up speaking, most Irish speakers will have no problem understanding each other.

"Léigh" is the root form of the verb, which is the form listed in most dictionaries. To use it in a sentence, we need a different form; in this case, the present tense third person singular, Léann.

This is pronounced in two syllables, with the accent on the first. The first, stressed syllable is pronounced like the Connacht version of "léigh," and the second syllable like the syllable "-an" in "woman." Just as in English, many Irish vowels in unstressed syllables are pronounced with a neutral schwa sound.

The Noun "Leabhar"
Next, we need the word for book, which in Irish is leabhar.

This is where we see our first warning sign. Any time you see a letter "h" following another consonant, you should leave your English language expectations at the door. In modern Irish writing, the h often indicates a change in pronunciation, in a process we'll talk about more in the next few lessons. For now, just know that the "bh" in "leabhar" makes what English speakers think of as a "w" sound.

The end result roughly rhymes with the English word "power." (Ulster pronunciation is more compressed and may sound more like "lore" or "lure" to the English ear). Be sure to follow the pronunciation links in the sidebar above to listen to the pronunciation in all three dialects.

The Name "Niamh"
Our English example sentence was "Jane reads a book." But Jane isn't a very Irish name, is it?

The Irish name Niamh comes from an old Irish word meaning "bright" or "glorious". It's the name of a figure from old Irish mythology, the queen of Tír na nÓg, the land of eternal youth, and the lover of Oisín, son of the mythical Irish hero Fionn mac Cumhaill.

Today it's a popular girl's name in Ireland, and is sometimes seen in anglicized forms in other countries.

The pronunciation is straightforward, until we come to the last few letters, where we see another warning "h".

This name is sometimes anglicized to "Neve," and it roughly rhymes with the English "sleeve".

Putting It Together
Now we have all the words we need to make our first sentence. Remembering our V-S-O word order, we have:

Léann (he or she reads) Niamh (the subject, Niamh) leabhar (a book).

Irish does not require an equivalent of the English "a"--"leabhar" can mean "a book" or just "book" depending on the context. We'll explore this more in a later lesson.

Exercises
When learning a language from a book, it can be tempting to neglect proper pronunciation. Every time you read a sentence or drill a flash card, you are drilling a pronunciation into your mind as well--and if it's the wrong one, it will take a lot of extra work to correct it.

If you're using this textbook for self-study, rather than working with a native or fluent speaker who can give you regular feedback on pronunciation, it is critical to get your pronunciation right the first time. That is why the exercises in Unit One will focus on pronunciation.

Exercise 1
Follow the links below to teanglann.ie and listen to how each word is pronounced in the three major dialects of Irish. Try to pronounce each word out loud both before and after you listen to the example. When you reach the end of the list, go back to the beginning. Repeat until you get it right every time. You don't have to be perfect, but you should not be pronouncing any words in inappropriate "English" ways--for example, pronouncing leabhar as if it had an English "b" or "h" in the middle.

Exercise 2
What is the Irish for each English word or phrase? Click to reveal the answer.

title: Irish/Unit 1/Lesson 1


text:
Arithmetic/Number Operations/Multiplication

Multiplication is one of the four basic operations of arithmetic. The operation is usually shown by the times symbol (*). This is the act of taking a number and adding it to itself a certain number of times. Think of multiplication as a shorthand way of performing repeated addition. For example, the following equation:
 * $$5 * 4 = 20$$

This means, "Multiplying five by four gives twenty," or put more simply, "five times four equals twenty." In this example, 5 and 4 are the factors, and 20 is the product, the result of the multiplication.

Commutativity
When multiplying two numbers together, it doesn't matter what order the numbers are placed in, since the outcome will be the same. That is to say for any two numbers $$x$$ and $$y$$, $$ x * y = y * x $$ For example, the two equations end up with the same result.
 * $$ 3 * 7 = 21 $$
 * $$ 7 * 3 = 21 $$

Associativity
When multiplying multiple numbers together, the order in which you multiply the numbers doesn't matter, since the outcome will be the same. For any three numbers $$x, y$$ and $$z$$, $$(x * y) * z = x * (y * z)$$ For example, the two equations will end up with the same result.
 * $$(2 * 3) * 4 = 6 * 4 = 24$$
 * $$2 * (3 * 4) = 2 * 12 = 24$$

The Multiplicative Identity
The number 1 is known as the multiplicative identity. This means if you multiply any number with one, you end up with that original number. For example:
 * $$4 * 1 = 4$$
 * $$6.24 * 1 = 6.24$$


text: Category:Book:Mirad Version 2

title: Category:Book:Mirad Version 2


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1945 02

P.03 - Contents Banner
THE AUSTRALASIAN RADIO WORLD

Devoted entirely to Technical Radio

and incorporating

ALL-WAVE ALL-WORLD DX NEWS

VOL. 9. - FEBRUARY, 1945. - No. 9.

P.03 - Publication Notes
PROPRIETOR — A. G. HULL

Manager - DUDLEY L. WALTER

Secretary - Miss E. M. VINCENT

Short-wave Editor — L. J. KEAST

For all Correspondence: City Office — 243 Elizabeth St., Sydney, Phone: MA2325

Office Hours — Weekdays: 10 a.m.-5 p.m. Saturdays: 10 a.m.-12 noon

Editorial Office — 117 Reservoir Street, Sydney

Victorian Advertising Representative — W. J. LEWIS, 379 Collins St., Melbourne, 'Phone MU4725

Subscription Rates: 6 issues - 5/3; 12 issues - 10/6; 24 issues - £1; Post free to any address.

Service Departments — Back Numbers, 1 /- ea. post free; Reply-by-mail Queries, 1/- each

Printed by Bridge Printery Pty. Ltd., 117 Reservoir Street, Sydney, N.S.W., for the proprietor of the "Australasian Radio World," Elizabeth St., Sydney (Footnote P.36)

P.03 - Contents
CONTENTS

CONSTRUCTIONAL —

An Alternating Design. . . . 5

Make Your Own Selenium Cell. . . . 17

TECHNICAL —

Square Wave Testing. . . . 11

Aesthetics of Reproduction. . . . 14

Filing Your Resistances. . . . 15

A Short Course in Radio Fundamentals. . . . 20

Voltage Doubling. . . . 25

The Miller Effect. . . . 27

SHORTWAVE REVIEW —

Notes From My Diary. . . . 30

New Stations. . . . 31

Loggings. . . . 32

THE SERVICE PAGES —

Answers. . . . 34

P.03 - Editorial
EDITORIAL.

Great interest will be aroused by the announcement in this issue that John Straede is to organise an amplifier contest of his own. Mr. Straede must fully appreciate the problems associated with such an undertaking, but is not deterred. He is buzzing around in his little car in search of advice about the many difficulties which may arise, hoping to nip them in the bud. In order to avoid disputes about the judging it is intended to have the decision reached by the audience as well as by competent judges who are not connected with the radio trade or with prize donors. Six major factors are to be taken into consideration in the judging: (1) volume; (2) freedom from distortion; (3) fidelity; (4) portability and flexibility; (5) accessibility and reliability; (6) cost of building. It is hoped to run a linearity curve for each amplifier submitted, also a frequency response curve, and to measure power output at actual grid current point. Every amplifier enthusiast will agree that the objects aimed at by Mr. Straede are indeed worthy, but many will have doubts about the ability of any single human being to handle the detail work involved in conducting such a contest with a representative entry of from fifty to a hundred amplifiers. To Mr. Straede we extend our best wishes for success to his ambitious proposal, but we hope that he will not be unhappy if, in spite of all precautions, the contest fails to settle the many debatable points about amplifier design and performance.


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1945 03

P.03 - Contents Banner
THE AUSTRALASIAN RADIO WORLD

Devoted entirely to Technical Radio

and incorporating

ALL-WAVE ALL-WORLD DX NEWS

VOL. 9. - MARCH, 1945. - No. 10.

P.03 - Publication Notes
PROPRIETOR — A. G. HULL

Manager - DUDLEY L. WALTER

Secretary - Miss E. M. VINCENT

Short-wave Editor — L. J. KEAST

For all Correspondence: City Office — 243 Elizabeth St., Sydney, Phone: MA2325

Office Hours — Weekdays: 10 a.m.-5 p.m. Saturdays: 10 a.m.-12 noon

Editorial Office — 117 Reservoir Street, Sydney

Victorian Advertising Representative — W. J. LEWIS, 379 Collins St., Melbourne, 'Phone MU4725

Subscription Rates: 6 issues - 5/3; 12 issues - 10/6; 24 issues - £1; Post free to any address.

Service Departments — Back Numbers, 1 /- ea. post free; Reply-by-mail Queries, 1/- each

Printed by Bridge Printery Pty. Ltd., 117 Reservoir Street, Sydney, N.S.W., for the proprietor of the "Australasian Radio World," Elizabeth St., Sydney (Footnote P.36)

P.03 - Contents
CONTENTS

CONSTRUCTIONAL —

A Circuit of D.C. Power. . . . 5

Reflex for Results. . . . 11

A Handy Tester Design. . . . 13

TECHNICAL —

Practical Aspects of High Fidelity. . . . 6

A Short Course in Radio Fundamentals — Part 2. . . . 14

The Amplifier Competition. . . . 18

Cathode Ray Tubes. . . . 19

Moving Coil Meters. . . . 25

Post-War Receiver Features. . . . 29

SHORTWAVE REVIEW —

Notes From My Diary. . . . 30

New Stations. . . . 31

Loggings. . . . 32

The Service Pages —

The Service Pages. . . . 34

P.03 - Editorial
EDITORIAL.

The future of the radio enthusiast who wants to experiment with transmitting appears to be assured. Those who want to own and operate their own transmitters should receive every encouragement and there is every evidence that this will become official policy in the immediate future. There is even a possibility that "hams" will be back on the air before the war is completely cleaned up. Restrictions will be unavoidable, of course. Considerable control will be necessary to prevent the ether being cluttered up, but it must be gratifying to hams to know that their war effort has been fully appreciated. Modern warfare is a matter of the finest of technicalities and it has now been revealed that one of the biggest factors in the winning of the Battle of Britain was the successful application of radiolocation technique, or radar, as we now call it for short. Just how many "hams" were directly connected with the development and application of radar is not known, but it is a pretty safe bet to say that probably 90 per cent gained a lot of their practical knowledge from radio experimenting. Now, with the return of peace, the logic of encouragement is clearly evident. Recently, several committees in the United States have been considering proposals for the allocation of post-war frequencies. It is noteworthy that not one committee has suggested any curtailment of the amateur bands and the only point in doubt concerns just how many additional bands should be handed over to the "ham." One suggestion is to add a "ham" band at around 15 metres and this would appear to be a most excellent one for DX work. A. G. HULL.


text:
User:MertGor

About Me

 * Systems Programming ( Assembly(nasm,gas),C/C++ ...)

title: User:MertGor


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1945 04

P.03 - Contents Banner
THE AUSTRALASIAN RADIO WORLD

Devoted entirely to Technical Radio

and incorporating

ALL-WAVE ALL-WORLD DX NEWS

VOL. 9. - APRIL, 1945 - No. 11

P.03 - Publication Notes
PROPRIETOR — A. G. HULL

Manager - DUDLEY L. WALTER

Secretary - Miss E. M. VINCENT

Short-wave Editor — L. J. KEAST

For all Correspondence: City Office — 243 Elizabeth St., Sydney, Phone: MA2325

Office Hours — Weekdays: 10 a.m.-5 p.m. Saturdays: 10 a.m.-12 noon

Editorial Office — 117 Reservoir Street, Sydney

Victorian Advertising Representative — W. J. LEWIS, 379 Collins St., Melbourne, 'Phone MU4725

Subscription Rates: 6 issues - 5/3; 12 issues - 10/6; 24 issues - £1; Post free to any address.

Service Departments — Back Numbers, 1 /- ea. post free; Reply-by-mail Queries, 1/- each

Printed by Bridge Printery Pty. Ltd., 117 Reservoir Street, Sydney, N.S.W., for the proprietor of the "Australasian Radio World," Elizabeth St., Sydney (Footnote P.36)

P.03 - Contents
CONTENTS

CONSTRUCTIONAL —

Balanced Linear V.T.V.M. .. . . 5

TECHNICAL —

Continental Design. . . . 11

Contrast Without Distortion. . . . 15

Aegis Components Do War Job. . . . 17

A Short Course In Radio Fundamentals - Part 3. . . . 18

Technical Review from U.S.A. .. . . 25

Production of Audio Frequencies. .. . . . . .. .. . 27

SHORTWAVE REVIEW —

Notes From My Diary. . . . 30

New Stations. . . . 31

Loggings. . . . 32

The Service Pages —

The Service Pages. . . . 34

P.03 - Editorial
EDITORIAL.

Several readers have written to let me know how much they appreciate the varied style of the articles now being presented in Australasian Radio World. From near and far come contributions, some of them possibly lacking in the niceties of journalism, but all from the hearts of enthusiastic radio men just like you and me. It takes an exception to prove the rule, and so I also find that some people are not in agreement with views expressed by contributors, and so they abuse me for not exercising greater editorial supervision. I can imagine that I am going to get into really hot water for publishing Mr. Stevens' article in this issue. Paul Stevens claims that Australian radio engineers have slavishly followed American design, thereby doing the wrong thing. Personally I do not think that Mr. Stevens has presented both sides of the case, nor do I think that his arguments are all entirely sound, yet I feel that the article is well worth publishing exactly as submitted. Some of my thin-skinned friends are going to be hurt by the inferences; others may be shocked by the audacity of anyone daring to suggest that our set designers are not infallible. My courage comes from the thought that in these days of so much talk about freedoms, that my readers should have the right to freely criticise, so long as their criticism is within the bounds of reason. Those who do not agree with views expressed will be gladly afforded space to state their claims and present their cases.


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1945 05

P.03 - Contents Banner
THE AUSTRALASIAN RADIO WORLD

Devoted entirely to Technical Radio

and incorporating

ALL-WAVE ALL-WORLD DX NEWS

VOL. 9 - MAY, 1945 - No. 12

P.03 - Publication Notes
PROPRIETOR — A. G. HULL

Manager - DUDLEY L. WALTER

Secretary - Miss E. M. VINCENT

Short-wave Editor — L. J. KEAST

For all Correspondence: City Office — 243 Elizabeth St., Sydney, Phone: MA2325

Office Hours — Weekdays: 10 a.m.-5 p.m. Saturdays: 10 a.m.-12 noon

Editorial Office — 117 Reservoir Street, Sydney

Victorian Advertising Representative — W. J. LEWIS, 20 Queen St., Melbourne, C1 'Phone MU5154

Subscription Rates: 6 issues - 5/3; 12 issues - 10/6; 24 issues - £1; Post free to any address.

Service Departments — Back Numbers, 1 /- ea. post free; Reply-by-mail Queries, 1/- each

Printed by Bridge Printery Pty. Ltd., 117 Reservoir Street, Sydney, N.S.W., for the proprietor of the "Australasian Radio World," Elizabeth St., Sydney (Footnote P.28)

P.03 - Contents
CONTENTS

CONSTRUCTIONAL —

An Improved Reflex Circuit. . . . 7

One-valve Test Oscillator. . . . 9

A Sound Design for an Audio Oscillator. . . . 13

TECHNICAL —

Tolerance in Set Design. . . . 5

A High-Fidelity Hint. . . . 11

Building the A.I.F. Broadcaster. . . . 12

A Short Course in Radio Fundamentals — Part 4. . . . 16

New Dutch Valves. . . . 22

SHORTWAVE REVIEW —

Notes From My Diary. . . . 23

New Stations. . . . 24

Loggings and Changes. . . . 25

THE SERVICE PAGES —

The Service Pages. . . . 26

P.03 - Editorial
EDITORIAL.

Now that censorship is being relaxed it is possible to tell some of the facts about the part which radio played in winning the war in Europe. It is now freely admitted that the British supremacy in radiolocation was of tremendous help. In the Battle of Britain we were using radiolocation so effectively that every time a German bomber arrived over England there was a team of Spitfires and Hurricanes waiting for it and a few thousand feet above it. The Germans gained the impression that England had unlimited numbers of fighter aircraft, whereas it was the work of the British radio engineers which told the R.A.F. just where and when to expect the German bombers. It has also been revealed that the Navy pays due tribute to radiolocation. It has been stated in English papers that the success of the Allied naval gunnery was due to the use of radar aiming and distance finding. The scientific application of radio knowledge is given full credit for victory in the Battle of Matapan. Directly and indirectly the radio enthusiast and the keen amateur transmitter have been responsible for the Allied supremacy in radar and communications. It is therefore only right and logical to expect the authorities to give every possible encouragement for the further development of radio as a scientific hobby. So far there is every indication that this is so, but it is the duty of everyone interested to get behind the Wireless Institute of Australia, as the recognised mouthpiece of amateur radio, and make sure that the subject is kept clearly before the minds of those officials who have been appointed to control the ether. — A. G. HULL.