text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1938 01

Link to Issue PDF
| WorldRadioHistory.com's scan of | Australasian Radio World - Vol. 02 No. 09 - January 1938 has been utilised to create the partial content for this page and can be downloaded at this link to further extend the content and enable further text correction of this issue: | ARW 1938 01

In general, only content which is required for other articles in this Wikibook has been entered here and text corrected. The material has been extensively used, inter alia, for compilation of biographical articles,  radio club articles and  station articles.

Front Cover
The Australasian Radio World

JANUARY 1, 1938; Vol. 2 - No. 9; Price, 1/-

Registered at the G.P.O., Sydney, for transmission by post as a periodical

Cover Photo: Photo of Valve Ageing Rack at Philips Factory, Camperdown, Sydney (See Page 8)

Highlighted Contents: More about the Battery Amateur Communications Superhet: Power-Pack and Amplifier Unit for the A.C. "Empire All-Wave Three": Latest List of World Shortwave Stations

P.02 - Editorial Notes
'''Editorial Notes. . .'''

Nil

P.02 - Contents Banner
The Australasian Radio World

Incorporating the

All-Wave All-World DX News

Managing Editor - A. Earl Read, B.Sc.

Vol. 2. - January, 1938 - No. 9.

P.02 - Contents
CONTENTS:

"Empire" Power Pack And Amplifier. . . . 3

1938 Contest For Best Amateur Telegraphist. . . . 8

Breaking Into The Amateur Game (12). . . . 10

Radio Ramblings. . . . 12

Radio Valves In The Making (1). . . . 14

Schedule Of PCJ Experimental Transmissions. . . . 16

Twenty-Five Years In Amateur Radio (9). . . . 18

World Shortwave Stations. . . . 19

Battery Amateur Communications Superhet. . . . 29

Eight-Valve T.R.F. Receiver Gives High Quality Output. . . . 36

National Field Day An Enjoyable Outing. . . . 38

What's New In Radio. . . . 41

All-Wave All-World DX News. . . . 43

Shortwave Review. . . . 44

DX News And Views. . . . 47

Australian Trained Radio Servicemen's Institute — Queensland Division. . . . 48

P.02 - Publication Notes
The "Australasian Radio World" is published monthly by Trade Publications Proprietary, Ltd. Editorial offices, 214 George Street, Sydney, N.S.W. Telephone BW6577. Cable address: "Repress," Sydney. Advertisers please note that copy should reach office of publication by 14th of month preceding that specified for insertion.

Subscription rates: 1/- per copy, 10/6 per year ( 12 issues) post free to Australia and New Zealand. Subscribers in New Zealand can remit by Postal Note or Money Order.

Printed by Bridge Printery Pty. Ltd., 214 George Street, Sydney, N.S.W., for the proprietors of the "Australasian Radio World," 214 George St., Sydney (Footnote P.48)

P.18 - Twenty-Five Years In Amateur Radio (9)
'''Twenty-Five Years In Amateur Radio. . . (9)'''

In this concluding instalment, the author discusses the relative merits of 5-metre aerial systems. He also gives details of further experiences in u.h.f. work, leading up to his establishment of a world DX record by putting 5-metre telephony signals into North Wales. By DON. B. KNOCK, Radio Editor, "The Bulletin."

BY the end of 1936, much progress had been made at VK2NO, with all kinds of directional aerial systems for 5-metre working, and at times some fearsome looking affairs sprouted around the shack, to the mystification of neighbouring residents.

From the original eight-wire beam with its "one-way traffic" limitations, arrays had passed through the stages of the twin radiator with reflector; twin dipole (end-fire) and Reinartz rotary, to the Bruce system.

There is little to choose between any of these types for local working (up to 100 miles) with the exception of the Bruce array. This system has already been described in "A.R.W." It has the highest gain of any in its simplest form of four half-waves in phase, and is bi-directional normally into the bargain. It is likely, however, to be a bit of a nuisance in windy weather unless one has adopted a very strong structural arrangement (which most hams don't do).

This system must be capable of 180-degree rotation with an accessible control, as the horizontal beam angle is around 15 degrees at 5 metres. Either side of that the signal falls off rapidly, both on transmission and reception. It is the best of the u.-s.-w. systems, in the writer's opinion, for those who want the best results.

The twin-dipole is very good. This is also for 180-degree rotation, but has a 45-degree angle and is end-fire. It is easily erected and rotated.

The simplest of all is the Reinartz rotary, being only 30 inches in diameter, but with a 45-degree angle in one direction. It must consequently be capable of 360 degrees rotation.

The system in use at the time of writing is a vertical W8JK "Flat-Top" beam. This has two full-waves out of phase with one-eighth wave spacing; is end-fire with about a 20-degree angle, and is a very convenient type for 180-degree rotation. This aerial is at present being tried out for possible overseas DX on 5 metres.

Atlantic Crossed On "Five" In 1926. The question of 5-metre DX has always been an interesting one to the writer, possibly because it is a tough nut to crack. The history of 5-metre communications shows that as far back as 1926, signals were sent across the Atlantic to Italy on 5 metres. There was never any two-way working in all instances of reported DX, and up to the present time such is still the case.

Late in 1936, the writer tackled the problem of advanced apparatus seriously, and a transmitter was designed using a 6L6 e.c. oscillator doubling from 10 to 5, driving a capacity-coupled RK25. This exciter unit was used to drive two Eimac 35T's in push-pull. The final stage would take a comfortable 150 watts input. Receivers were also tackled, and an eight-valve superhet with 5,000 k.c. i.f. channel was evolved.

The transmitter was tested out on various beam arrays, and for a considerable period the twin-dipole with 600-ohm line feed was employed, with a Reinartz rotary fed by twisted pair as a stand-by.

In the test days organised by W.I.A. (N.S.W. division) considerable success was obtained. The first surprise came when VK2DN, of Deniliquin, 360 miles distant, logged the i.c.w. test signals from VK2NO on schedule for a brief period, and this was followed by two-way contact during day and night with VK2ZC at Newcastle, 70 miles distant.

The biggest surprise of all came this year, when an ultra-shortwave observer in Pwllheli, North Wales, claimed to have heard telephony on 5 metres from VK2NO. Conjecture was rife, and doubts were freely expressed, but the hard facts turned up in the form of the log extracts of the signal, mailed from North Wales.

The interesting part of it is that VK2NO was at the time using the Reinartz rotary in communication with another Sydney station, and, furthermore, the signal had been heard but not identified on several occasions around that period by the North Welshman. This confirmation constitutes the world's record for transmission and reception on 5 metres, and now it is a matter of sticking at the job with earnest co-operation until two-way working is effected.

Regular Schedules With ON4AU. At the present time, schedules are being kept regularly with the well-known Belgian, ON4AU. He is using first-class equipment for c.w. transmission and reception on 56,080 k.c. ON4AU has 250 watts output with a beam array directed over the Great Circle route, and special W.E. u.-h.-f. valves are employed in the final transmitter stage. His receiver is a t.r.f. type using acorn valves.

In order to be fully up to the mark, the station at VK2NO has been re-modelled, and the transmitter now includes an extra buffer stage with two 801's in push-pull before the 35T's. The final has been re-designed for higher efficiency.

The most interesting part of the equipment is the new receiver for the combined job of straight c.w. and super-regenerative reception. Considerable work has been done with possible c.w. receivers previously, using standard valves, but the results had always been disappointing. Recently this new receiver was completed, and it uses a 956 acorn t.r.f. amplifier, 954 electron-coupled detector, EBC3 as interrupter when "supering" is wanted, and 41 audio.

A heterodyne oscillator has been incorporated, putting an old idea to modern use. This oscillator is at 20 metres, and the fourth harmonic is used to beat with the 954 detector, which can then be used in a non-oscillating but sensitive condition.

The method of operation is very simple. A c.w. signal is first tuned in with the detector oscillating (harmonics from c.c. stations on other bands are very useful for this), and then the beat oscillator is switched in and the detector regeneration backed of slightly. The result is a remarkably stable signal, with no loss of signal strength. The receiver handles on c.w. just as easily as if one were using it on 20 metres.

In use it has proved to be a revelation, and far superior to any receiver yet tried. Some idea of the efficiency can be gained when it is stated that c.w. harmonics of stations as far as 20 miles away can be heard at R7 on 5 metres when working on 20 and 10 metres. These results, however, appear to be obtainable only with valves such as the 956 and 954.

"Acorns" Well Worth While. "Acorns" are admittedly expensive, but despite their relatively high price, it is money well spent where it is a case of determination to get the best ultra-short-wave results. To spend money on the transmitter side and treat the receiver as an afterthought is less than half doing the job.

Apart from the primary interest to-day of ultra-short-wave experimentation, the writer does not completely neglect the ordinary routine of amateur communication, and may occasionally be found on 20-metre c.w. and 'phone, mostly in the early mornings, and very rarely on 40 metres.

In July this year, a considerable amount of 40-metre communication was obtained with the Mackay Aerial Survey Expedition in Central Australia, and this, being something different to the usual kind of communication normally to be had on 40 in these times, was an interesting interlude.

In conclusion, the writer would say that, despite the utility of modern radio-telephone communication, the telegraphy side is still as important as ever it was, and urges the amateur in general to strive to keep his hand in on the key. The reasons for such advice would take too much space, but they are numerous and indisputable.

Radio "Grandest Of Hobbies." After 25 years of experience in different forms with this yet infant science of radio communication, the writer considers that it is the grandest of hobbies for old and young, that if only the world at large could be made to realise it, amateur radio is a powerful weapon for world peace by intimate contact between fellow men; and that, progressive as radio is, it still has a long way to go. There is no end to its possibilities. (Conclusion).

Photo of 2NO 5 metre transmitter
The five-metre transmitter used by VK2NO. It put telephony signals into North Wales, and telegraphy across the Tasman to New Zealand, It has four stages, consisting of a 6L6 electron-coupled oscillator from 10 to 5 metres, capacity-coupled to an RK25. This exciter is linked to a buffer stage with two 801's in push-pull, and this in turn is linked to the final, using two Eimac 35T's in push-pull, with 150 watts input.


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1938 02

Link to Issue PDF
| WorldRadioHistory.com's scan of | Australasian Radio World - Vol. 02 No. 10 - February 1938 has been utilised to create the partial content for this page and can be downloaded at this link to further extend the content and enable further text correction of this issue: | ARW 1938 02

In general, only content which is required for other articles in this Wikibook has been entered here and text corrected. The material has been extensively used, inter alia, for compilation of biographical articles,  radio club articles and  station articles.

Front Cover
The Australasian Radio World

February 1, 1938; Vol. 2 - No. 10; Price, 1/-

Registered at the G.P.O., Sydney, for transmission by post as a periodical

Cover Photo: Photo of Miss Jean Batten, noted NZ air-woman, being televised in BBC studios (see story on page 8)

Highlighted Contents: "1938 Fidelity Dual-Wave Six": More About the "Empire All-Wave Three": VK2NO Advanced U.H.F. Receiver: Result of Third Shortwave DX Contest: Latest World Shortwave News.

P.02 - Editorial Notes
'''Editorial Notes. . .'''

Nil

P.02 - Contents Banner
THE AUSTRALASIAN RADIO WORLD.

Incorporating the

ALL-WAVE ALL-WORLD DX NEWS.

Managing Editor:

A. EARL READ, B.Sc.

Vol. 2. - FEBRUARY 1, 1938 - No. 10.

P.02 - Contents
CONTENTS:

The Fidelity Dual-Wave Six. . . . 3

New Ever Ready Factory Opened By Prime Minister. . . . 8

Radio Ramblings. . . . 10

More About The A.C. Empire All-Wave Three. . . . 14

Aden Amateur Station On The Air. . . . 16

Five Metres In S. Australia. . . . 18

VK2NO Advanced U.H.F. Receiver. . . . 19

Radio Valves In The Making (2). . . . 24

Radio Step By Step (14). . . . 27

Lavishly-Equipped Radio Service Workshop. . . . 29

What's New In Radio. . . . 32

Breaking- Into The Amateur Game (13). . . . 35

The All-Wave All-World DX News. . . . 37

Shortwave Review. . . . 38

Third S.W. DX Contest. . . . 41

Round Table QSO Smashes Previous Record. . . . 42

Around The Shacks (6). . . . 43

1937 Eventful Year For Shortwave Dxers. . . . 44

DX News And Views. . . . 47

P.02 - Publication Notes
The "Australasian Radio World" is published monthly by Trade Publications Proprietary, Ltd. Editorial offices, 214 George Street, Sydney, N.S.W. Telephone BW6577. Cable address: "Repress," Sydney. Advertisers please note that copy should reach office of publication by 14th of month preceding that specified for insertion.

Subscription rates: 1/- per copy, 10/6 per year ( 12 issues) post free to Australia and New Zealand. Subscribers in New Zealand can remit by Postal Note or Money Order.

Printed by Bridge Printery Pty. Ltd., 214 George Street, Sydney, N.S.W., for the proprietors of the "Australasian Radio World," 214 George St., Sydney (Footnote P.48)

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


text: Irish/Vocabulary/Bedroom

title: Irish/Vocabulary/Bedroom


text:
User:Cenana

cisco ise can improve network safety. If you follow the Cisco ISE design best practices, then you can defend your business against incoming network threats and enhance your security capabilities.

As such, you must deploy ISE correctly. To do this, you’ll need to follow a detailed Cisco ISE deployment guide.

The first step is ensuring that you have the right skills to deal with an installation like this. You have to understand what needs to be set up, where everything goes, and so on. If you don’t possess these skills, then you must find someone who does.

title: User:Cenana


text:
Planet Earth/1g. Coriolis Effect: How Earth’s Spin Affects Motion Across its Surface

Earth’s Inertia
As a spinning spheroid, Earth is constantly in motion, however one of the reasons you do not notice this spinning motion is because the Earth’s spin lacks any acceleration, and has a set speed or velocity. To offer an example that might be more familiar, imagine that Earth is a long train traveling at a constant speed down a very smooth track. The people on the train do not feel the motion. In fact, the passengers may be unaware of the motion of the train when the windows are closed and they do not have any reference to their motion from the surrounding passing landscape. If you were to drop a ball on the train it will fall straight downward from your perspective, and give the illusion that the train is not moving. This is because the train is traveling at a constant velocity, and hence has zero acceleration. If the train were to slow down, or speed up, the acceleration would change from zero, and the passengers would suddenly feel the motion of the train. If the train speeds up, and exhibits a positive acceleration, the passengers would feel a force pushing them backward. If the train slows down, and exhibits a negative acceleration, the passengers would feel a force pushing them forward. A ball dropped during these times would move in relationship to the slowing or increasing speed of the train. When the train is moving with constant velocity and zero acceleration we refer to this motion as inertia. An object with inertia has zero acceleration and a constant velocity or speed. Although the Earth’s spinning is slowing very very slightly, its acceleration is close to zero, and is in a state of inertia. As passengers on its surface we do not feel this motion because Earth’s spin is not speeding up or slowing down.

Differences in Velocity due to Earth’s Spheroid Shape
The Earth is spherical in shape, represented by a globe. Because of this shape, free moving objects that move across the Earth’s surface long distances will experience differences in their velocity due to Earth’s curvature. Objects starting near the equator and moving toward the pole will have a faster starting velocity, because they are starting at the widest part of the Earth, and slow down as they move toward the poles. Likewise, objects starting near the poles and move toward the equator will increase their velocity, as they move toward the widest part of the Earth’s spin. These actions result in accelerations that are not zero, but positive and negative. As a consequence, the path of free moving objects across large distances of the spinning surface of Earth curve. This effect on the object’s path is called the Coriolis Effect. Understanding the Coriolis effect is important to understand the motion of storms, hurricanes, ocean surface currents, as well as airplane flight paths, weather balloons, rockets and even long-distance rifle shooting. Anything that moves across different latitudes of the Earth will be subjected to the Coriolis effect.

Tossing a Ball on a Merry-go-round
The best way to understand the Coriolis effect is to imagine a merry-go-round, which represents a single hemisphere of a spinning Earth. The merry-go-round has two people, Sally who is sitting on the edge of the spinning merry-go-round (representing a position on the Equator of the Earth), and George who is sitting at the center of the merry-go-round (representing a position on the North Pole of the Earth). George at the North Pole has a ball. He rolls the ball to Sally at the Equator. Because Sally has a faster velocity as she is sitting on the edge of the merry-go-round, by the time that the ball arrives at Sally’s position she will have moved left, and the ball rolled straight would miss her location. The ball’s path is straight from perspective above the merry-go-round, but from the perspective of George it appears that the ball’s path is moving toward the right of Sally. The key to understand this effect, is that the velocity of the ball increases as it moves from George to Sally, hence its acceleration is positive, while both George and Sally have zero acceleration. If we were to map the path of the rolled ball from the perspective of the merry-go-round, the path of the ball will curve clock-wise. Since the Earth is like a giant merry-go-round, we tend to view this change to the path of free moving objects as a Coriolis force. This force can be seen in the path of any free moving object that is moving across different latitudes. The coriolis force adheres to three rules.

The Rules of Earth’s Coriolis Force

 * 1) The Coriolis force is proportional to the velocity of the object relative to the Earth; if there is no relative velocity, there is no Coriolis force.
 * 2) The Coriolis force increases with increasing latitude; it is at a maximum at the North and South Poles, but with opposite signs, and is zero at the equator in respect to the mapped surface of the Earth, but does exert some upward force at the equator.
 * 3) The Coriolis force always acts at right angles to the direction of motion, in the Northern Hemisphere it acts to the right of the starting observation point, and in the Southern Hemisphere to the left of the starting observation point. This results in Clockwise motion in the Northern Hemisphere and Counter-Clockwise motion in the Southern Hemisphere.

These paths are difficult to empirically predict, as they appear to curve in respect to the surface of the Earth. One example where the Coriolis force comes into your daily life is when you travel by airplane crossing different latitudes. Because the Earth is moving below the airplane as it flies, the path relative to the Earth will curve, resulting in the airplane having to adjust its flight path to account for the motion of the Earth below. The Coriolis force also affects the atmosphere and ocean waters because these gasses and liquids are able to move in respect to the solid spinning Earth.

How to calculate the coriolis effect for a moving object across Earth’s surface. The red line is an object on earth traveling from point P at the velocity $$V_t$$ (V_total). For the coriolis effect only the horizontal speed $$V_h$$ (V_horizontal) is of importance. To get $$V_h$$ from $$V_t$$ one can say:

 * $$v_t \cdot \sin \theta = v_h$$

The coriolis force is then calculated by taking:

 * $$coriolis force = 2mv_t \cdot \omega \cdot \sin \theta$$

where $$\omega$$ is velocity of the Earth’s spin at the Equator, and m is the mass of the object.

A Common Misconception Regarding Flushing Toilets in Each Hemisphere
A common misconception is that because of the Coriolis effect there were differences in the direction of the swirl of draining water from sinks, toilets and basins depending on the hemisphere. This misconception arose from a famous experiment that was conducted over a hundred years ago, where water was drained from a very large wooden barrel. After the water was allowed to sit and settle for a week (so that there was no influence of any agitation in the water). A tiny plug at the base on the barrel was pulled, and the water slowly drained out of the barrel. Because of the large size of the barrel, the water moved with different velocities across the breath of the barrel. Water on the equator side of the barrel move slightly further than the water on the pole side of the barrel resulting in a path toward the right in the Northern Hemisphere, resulting in a counter-clockwise direction of the draining water.

Since this famous experiment, popular accounts of the Coriolis effect have focused on this phenomenon, despite the fact that most drains are influenced more by the shape of the basin and flow of water. Rarely do they reflect the original experimental conditions of a large basin or barrel, and water that is perfectly settled in the basin. Recently the experiment has been replicated with small child swimming pools, (see https://www.youtube.com/watch?v=mXaad0rsV38) about several feet across. Even at this small size, it was found that the water drained counter-clock-wise in the Northern Hemisphere, and clock-wise in the Southern Hemisphere. Note that the effect will be more pronounced the closer the experiment is conducted near the poles.

Why the Swirl is in the Opposite Direction to the Movement?
Why does the water swirl through the drain opposite to the direction of movement of the water? The motion of the water is relative to the drain plug, since the path from the equatorial side will be moving faster than at the center drain plug, the path will curve right in the Northern Hemisphere, resulting in a path that overshoots the center drain plug on the right side, from this point near the drain plug, the water will be pulled by gravity to flow through the drain toward the water’s left side resulting in a counter-clock-wise direction as it drains. In the Southern Hemisphere it will be in the opposite direction. Satellites that track hurricanes and typhoons demonstrate that storms will curve to the right in the Northern Hemisphere and left in the Southern Hemisphere, but the clouds and winds will swirl in the opposite direction into the eye of the storm in a counter-clock-wise direction in the Northern Hemisphere and clock-wise direction in the Southern Hemisphere—similar to experiments with large barrels and child-size swimming pools. However, the storm’s overall path will be in a clock-wise direction in the Northern Hemisphere and counter-clock-wise direction in the Southern Hemisphere. This is why hurricanes hit the eastern coast and Gulf of Mexico in North America. Including the states of Florida, Louisiana, Texas, the Carolinas, Georgia and Virginia, and rarely if ever the western coast, such as California and the Baja California Peninsula of Mexico.

The Trajectory of Moving Objects on Earth’s Surface
If the trajectory of the free moving object does not cross different latitudes the path will be straight, since velocity in relationship to the Earth’s surface will remain the same, and acceleration will be zero. Coriolis effect behaves in three dimensions and the higher the altitude the more velocity will be exerted on the object. This is because the object’s position higher in the sky will result in a longer orbit around the Earth, and quicker velocity. Thus, changes in velocity can occur at any latitude if the free moving object changes altitude, and at the equator this force is vertical, leading to a peculiar net flow upward of air around the equator of the Earth, which is called the Intertropical Convergence Zone.


text: Category:Book:End-user Computer Security/Book part/Book preliminaries


text: Category:Book:End-user Computer Security/Book part


text: Category:Book:End-user Computer Security


text: Category:Book:End-user Computer Security/Book part/Book preliminaries/Book introduction


text: Category:Book:Planet Earth

title: Category:Book:Planet Earth


text:
User:Lelandken/sandbox

Hello!

title: User:Lelandken/sandbox


text:
User talk:Lelandken/sandbox

HiLelandken (discuss • contribs) 18:42, 26 May 2020 (UTC)

title: User talk:Lelandken/sandbox


text:
User talk:Lelandken

hi

title: User talk:Lelandken


text:
User:Arundquist77

Andy Rundquist is a physics professor at Hamline University in St. Paul Minnesota. He also teaches in the Computational Data Science program.

title: User:Arundquist77


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1940 01

P.02 - Editorial Notes
'''Editorial Notes. . .'''

Nil

P.02 - Contents Banner
The Australasian Radio World

Incorporating the

All-Wave All-World DX News

Managing Editor - A. Earl Read, B.Sc.

Vol. 4. - JANUARY, 1940 - No. 8.

P.02 - Contents
CONTENTS:

The Daventry Dual-Waver. . . . 3

The Story Of R.C.S. Radio (2). . . . 6

Five-Band Communications Superhet. . . . 8

Service Equipment (3). . . . 10

Vulcan Pre-Selector Unit. . . . 13

Choosing A Microphone. . . . 15

"Radio World" All-Wave Oscillator. . . . 17

Waverley Radio Club Notes. . . . 25

What's New In Radio. . . . 26

New Headquarters For Marconi School. . . . 28

"Communications Eight" A Fine Performer. . . . 30

Shortwave Review. . . . 31

Broadcast Band DX Notes. . . . 37

P.02 - Publication Notes
The "Australasian Radio World" is published monthly by Read Publications. Editorial offices, 117 Reservoir Street, Sydney, N.S.W. Telephone FL2842. Cable address: "Repress," Sydney. Advertisers please note that copy should reach office of publication by 14th of month preceding that specified for insertion.

Subscription rates: 1/- per copy, 10/6 per year (12 issues) post free to Australia and New Zealand.

Printed by Bridge Printery, 117 Reservoir Street, Sydney, N.S.W., for the proprietors of the "Australasian Radio World," 117 Reservoir St., Sydney (Footnote P.40)

P.31 - Shortwave Review
Shortwave Review CONDUCTED BY ALAN H. GRAHAM. Summer Conditions: Night Reception IBest * Many New Stations Reported * Latest News of Projected Stations and Schedule Changes * Amateur Bands and UHF Notes * Full List of the Month's Loggings. Random Jottings. Review Of C<>nditions. With the close of the year, summer conditions become more and more evident, with a definite falling off in morning reception; with conditions during the forenoon and early after- noon very poor; with an ever-increasing noise-level making things difficult on the lower frequencies; and, finally, with evening reception splendid. From about 8.30 p.m. conditions on all bands between 13 and ·31 metres are really excellent. Signals on 13 and 16 metres are worth some attention, their clarity being a con- vincing proof that it is po~sible to find real entertainment on the shortwave bands. New Stations Listed. Included in the list of the month's loggings readers will find many new stations. Located in every quarter of the globe, many of these new stations are of outstanding interest to keen dx-ers. Fears expressed in some quarters that the outbreak of war would result in drastic curtailment of shortwave transmissions are now shown to have been quite groundless. As a matter of fact, the tendency is definitely in the other direction. Each month readers of these columns will have noted details of projected transmitters, and many of these will take the air early this year. With the development of shortwave broadcasting as a means of spreading -propaganda, few countries can afford to remain silent, and governments throughout the world are hastening to ensure that their views will be aired to the world at large. An interesting development in this direction is the inauguration of an Australian short- wave service, full details of which are given elsewhere in these columns. Overcrowding On The Shor twave Channels. This considerable increase in the number of shortwave transmitters now on the air, whilst providing SWL's with much interesting DX, also has very obvious drawbacks. For some time past listeners have been concerned at the overcrowding on some of the shortwave broadcast bands. At the present time, the 30-31 metre band is most adversely affected, as there are many more stations operating on these frequencies than can be comfortably accommodated. Moreover, there has been a veritable stampede to acquire frequencies on the newly-announced .J.1-metre broadcast band, on which over 30 station:; have already made reservations, despite the fact that the band only covers lOOkc. At present the higher frequency bands are not crowded, but ., definite tendency by many European and American stations to utilise aliocations on 13, 16 .and 19 metres will soon alter that. Amateurs Still Interest. Despite the number of amateur stations compulsorily off the air be

cause of the war, interesting 20-metre DX is still reported by many readers who are mainly concerned with ama- teur band loggings. A full list of countries in which amateur transmitt~rs a~e still permitted to operate is given m the Amateur Review section.

News (?) Broadcasts. Since the first n ovelty of the war has worn off, and the full weight of the censorship regulations have been felt, the majority of the n ews broadcasts lack interest. At times they are merely boring, consisting chiefly of futile and inevitably incorrect speculation, endless repetition of the same items, and fantastic propaganda. Even the American sessions lack spice. Details of news broadcasts and weekly war talks from Daventry are worth noting. Full news bulletins are given at the following times (the transmitters shown are beamed towards Australia) :-At 2 a.m. (GSJ, GSF, GSG);

&t 3.30 a.m. (GSD); at 7.45 a.m. (GSD); at 10.30 a.m. (GSC); at 4.15 p.m. (GSD, GSB); at 7 p.m. (GSD); at 9.30 p.m. (GSJ, GSF, GSG) and at ll.15 p.m. (GSJ, GSF, GSG). Interesting programmes heard regularly from Daventry include "London Log," with the well-known B.B.C. personality, Howard Marshall, at 5.30 p.m. on Saturdays and at 1.1·5 and 8.45 a.m. on Sundays; "Back- ·ground to the News" on Tuesdays and Fridays at 1.15 and 10.15 a .m. and 4.45 p.m.; "In England Now," on Wednesdays and Saturdays, at 1.15 and 8.45 a.m. and 6.15 p.m.; "Matters of Moment," on Thursdays, at 1.15 a.m. and 2.30 and 7.30 p.m. Official Observers. A word of very heartfelt praise to · the Official Observers who contribute so much to the success of this short- wave section of the "Radio World." We regret to record the resignation of two of our West Australian Ob- servers, Messrs. George La Roche nnd Cyril Anderson. Our best wishes to both, especially to 0.M. .Cyril, who is now serving with the 2nd A.I.F. Readers Repor>ts Requested. Readers are requested to write the Shortwave Editor on any matters con- cerning these columns. Reports of reception conditions are especially appreciated; all such reports will be acknowledged. Enquiries on any matters relating to shortwave reception will be answered oy mail. Addres~ all letters to Alan H. Graham, 258 Lower Plenty Rd., Rosanna, N22, Victoria. Schedules Andorra. Another new country for the keen dx-er. Reports from overseas indicate that "Radio Andorra" has been testing on .the 2·5-metre band. Exact frequency is a bit obscure, being given variously as 11850kc. and 11835 kc. For those readers whose geography is a little rusty, we might mention that Andorra is in the East- ern Pyrenees, being a small, semiindependent State of 190 square miles, which pays a small tribute to France and Spain as joint suzerairn;. 'I'he chief industry is smuggling. Hi. Australia. The new Australian station in Perth, VL W, has been reported testing on both 48 and 25 metres. VL W is one of the stations to be used In the Australian shortwave service, which will have come on the air by the time these notes appear in print, the opening date being December 22. Full schedule for these transmissions are:- For Europe, through VLQ, 9615kc.,
 * Latest Station Changes And

31.2m.: In German, Dutch, French and English. From 5 to 7 p.m. For Southern Europe, through VLQ2, 11870kc., 25.25m. In Turkish, Italian, Spanish, English and Arabic. From 5.30 to 6.30 p.m. For North America, through VLQ. In English. From 7 to 8 a.m. For North America and the Pacific, through VLQ. In English. From 7.·30 to 8.30 a .m. For India, through VLQ. In English. From 11.15 to 11.45 p.m. For South America, through VLQ. In English and Spanish. From 9.30 to 10 p.m. For Africa, through VLW3, 11830 kc., 25.36m. In Engl.ish and Afrikaans. From 3.30 to 4.30 p.m. For the East, through VLR, 958CJ kc., 31.32m. In English and Dutch. From midnight to 12.30 a.m. Through VLR3, 11880kc., 25.23m. In Engfo,h. From 9.30 to 10 a.m. Algeria. Plans for a powerful shortwave transmitter are now being considered. It is hoped to cstar.t transmissions a~ the end of this year. Belgian Congo, The new 250-watt .3tatio!l at Leor,ddville operates under the call, OQ· 2AA, on either 9525 or .l5170k.?., :n.49 or 19.77m. However, its present schedule, 10.25 a.m. till noon, make~ n :ception in this country rather improbable for the present, ar, !e:ist. China. No appearance of the "Shortwave P.eview" seems complete these days without news of additional Chine~e sr.ations. The latest transmitter i~; reported as being on 7970kc., 38.3m. Located in Shanghai, the call of this station, already reported in New Zealand, is thought to be XHHB. Some details re XPSA recently re- ceived may be of interest. Located at Kweiyang, XPSA operates on 7010kc., 42.2m. (official frequency is given as 6.970kc., but that is definitely wrong). Power is lOkw.; and the station ir;; on the air from 6-9 a.m., and from 8.30 p.m.-1.·30 a.m. News in English is ·broadcast at 11.30 p.m. Reports are greatly appreciated. Cuba. Further information regarding the new station at Santa Clara, COHI, indicates that it will also transmit 011 the 25-metre band, on approx. 11800 kc. (Radex). Latest alterations in frequencies of Cuban stations are as follow:-COCE, on 12230kc., 24.53m.; COCX, on 117.53 kc., 25.52m.; COCA, on 9700kc., 30.93 m.; and COBC, on 9350kc., 32.08m. France. The new lOOkw. stations are gradually coming on the air. At present

two of these are operating on 9680kc., 30.99m., and 11843kc., 25.35m. No calls have yet been assigned, the stations merely being in the experimental stage as yet. Latest official schedules from Paris show a change in call-sign for the 11885kc., 25.23m., transmitter; it now operates with the calls TPB-11 and TPB-12 (not TPA-3 and TPB-7, as before). French lndo-China. Apart from "Radio Saigon.'' there has been considerable activity by . other stations in F.J..C. "Radio Vol· onte," in Saigon, is reported as operating regularly on 7100kc., 42.25m., commencing a recorded programme at 11.30 p.m. with the "Marseillaise." In addition, "Radio Boy-Landry" is transmitting on three frequencies, namely, 6215kc., 967.Gkc., and 11685 kc., or 48.27m., 31.0lm. and 25.68m. Hawaii!. It is reported that the '·Voice of Hawaii" programmes are being re- layed through KHB, Kahuku, on 17120kc., 17.5m., from 10-10.30 a.m. on Sundays (QSA-5). Eire. The latest available schedule for the Irish station at Athlone is:-On 17840kc., 16.82m.: Daily 3.30-5 a.m.; odd days of the month, 7.30-11.30 a.m.; even days of the month, 7.30- 8.30 a.m. On 9595kc., 31.27m.: Eve;-, days of the month, 9.30-11.30 a .m. and 12.30-1 p.m. Luxembourg. "Radio Luxembourg," recently heard on 25 metres, have been testing on 6090kc., 9527.5kc., 11782 .. 5kc. and 15330kc. ( 49.26m., 31.49m., 25.46 m. and 19.56m.). Whether these ex- perimental transmissions are still being carried on is obscure, as "Radio Luxembourg" has not been reported in this country for some weeks now. QRA for reports is Wireless Publicity Ltd., Electra House, Victoria Embankment, London, WC2. (Tune-In). Mauritius. VQSJM, Port Louis, is reported from several sources as broadcasting irregularly on 7190kc., 41.7m. (Radex, Tune-In). Paraguay, ZP-8, Asuncion, to operate Ol• 11850kc., 25.32m., with a power of 500 watts, is a new station (Universalite). Switzerland. The Swiss transmitters of the League of Nations are again on the air. HBO, HBL and HBP are all operating for North America around 10 a.m., whilst HBF, 18450kc., 16.2m., transmits a programme for the Orient on Saturdays from 4.45 to 6.45 p.m. Syria.

It is understood that a new station at Damascus is now transmitting on 12295kc., 24.4m. U.S.S.R. A feature of the past few weeks has been the number of new Russian stations heard. No calls are available for these stations, but full details of frequencies and times of tranmission are given in the list of the month's loggings. Yugo-Sl'avia. Full details of the Belgrade stations are now available. YUB (this is understood to be new call for station previously listed as YUA) on 6100kc., 49.18m.; YUC, on 9505kc., 31.57m.; YUE, on ll 735kc., 25.57m.; and YUF-YUG, on 15240kc., 19.6.Sm. (Universalite). Ultra-High-Frequency Notes. Conditions Disappoint. The promise of some good U.H.F. reception during December was not fulfilled. After a good period at the end -of November, the unsettled weather in our locality :·esulted in almost a complete "black-out" during December. The police bunds were most affected, and, at the time of writing, no signals have been heard on 8 and 9 metres for the past fortnight. Conditions on 10 and 11 metres are very little better. Police Bands. Towards the end of November con- ditions were quite good, and one or two additional loggings were made. Police stations definitely identified this year are:- WPDS, St. Paul, 33800kc., 8.9 m. KQCI, Glendale, 33800kc., 8.9 m. KQBH, Kansas City, Kansas, 3-3100 kc., 9.06m. KQAN, Fort Worth, 33100kc., 9.06m. WRBH, Cleveland, 33100kc., 9.06m. KQAO, Long Beach, 33100kc., 9.06m. KQ-, National City, 33100kc., 9.06m. KQBV, Los Angeles, approx. 9.4m. WQIE, Newark, 30700kc., 9.7m. KQBR, Alameda, 30700kc., 9.7m. WQKB, Evansville, 30700kc., 9.7m. 11-M'etre Band Loggings. Only WSXNU remains a regular on 11 metres, and signals from this station are now very poor. The other stations listed below were heard in the last week of November. W4XA, 26150kc., ll.47m., Nashville: Only very occasionally now; usually with foo.tball descriptions on Sunday mornings. WSXNU, 25950kc., ll.56m., Cincinnati: Very good at end of November;

heard reguiariy still, but signais weak and hard to copy. W9XA, 26100kc., ll.49m., Kansas City: Frequency altered again from 26000kc. Seldom heard. W9XH, 26050kc., 1L51m., South Bend: Heard once at end of November; closes 9.30 a.m. W9XJL, 26100kc., ll.49m., Superior: Heard, with bad QRM from W9XA, late in November. Signals weak. W9XPD, 25900kc., ll.58m., St. Louis: Very weak, but heard at times just above WSXNU. 9-Metre Band Notes. No sign yet of the 31600kc. broad- cast stations. Even if this band does open up, it will probably be of little value, as the latest information available shows oyer 30 American stations licensed to use this frequency. The harmonic of KGEI on 9.78m. has been heard very well indeed in New Zealand, though it seldom ex- ceeded R4 in our locality. Amateur Bands * Review. The following list -of countries in w~ich amateur stations are still permitted to transmit is as accurate as is possible under the circumstances. Incidentally, readers will have noted that Cuban amateurs are no longer on the air. The war is not the reason for this ban imposed by the Dire:- tor -of Radio.

Countries in Which Amateurs Stiil Operate: South America: Colombia, Chile, Brazil, Bolivia, Argentina, Ecuador, Peru, Paraguay, Uruguay, Venezuela. Central America: Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, Canal Zone. West Indies: Puerto Rica, Domini- can Republic, Haiti. Europe: Belgium, Holland, Portugal, Spain. Africa: Belgian Congo, Tangier International Zone. Oceania: Hawaii, Philippines, Dutch East Indies, American islands. Asia: Japan, China. North America: United States, Mexico, Alaska

Calls * Heard. (Reports for 20 metres from Messrs. Bantow, Hastings, Cushen; Taylor and Chapman. For 10 metres, from Mr. Taylor and the S.W. Ed.) 10 Metres. South America: CE3AC (Chile). Oceania: KA- lER, lGX, lME, lLZ, (Philippines); K6- BAZ, GQF, MVV, OJI, PIT, PLZ, QLB, QRD, QXU, QXY, ROJ, RRM, PIR (iHawaii). United States: W- lCND, lBBX, lHDQ, lLMB, 2LIR, 2FXB, 2CJ A, 2CQX, 2AIH, 2KAX, 3BBA, 3GNA, 3A WX, 3GRO, 4FUM, 4MV, 4EDD, 5IJM, 6FFN, 6FZD, 6IEF, 6IMI,

6KYL, 6MIW, 6NWG, 6P Ai, 6PMJ, 6QHE, 6QPH, 6DUC, 6RCT, 60XV, 6QUZ, 6CDO, 6HGN, 6AWV, 6QMJ, 6NKF, 60AK, 6FVM, 6RRU, 7FVO, 7GFK, 7GMV, 7GUI, 7HCD, 7HCS, SSOE, 9BRZ, 9JUI, 9KDA, 9RGT, 9ZIX, 9DLC, 9EW, 9ZN A, 9LMX, 9YZK, 9ARK, · 9NWN, 9CXV. 20 Metres. South America. Venezuela: YV5AK. Ecuador: HClFG. Argentina: LU4DM. Peru: OA- 4L, 4C, 4AI, 4R. Chile: CE- lAR, lAO, 3EW, 3CZ, 3CG, 3AC, 3BK, 3CE, 3AG, 4AC. Brazil:. PY- 2AR, 2SN. Central America. Costa Rica: TI2RC. Africa. Tangier International Zone: EKlAF. Belgian Congo: OQ5AB. Pacific. Guam: KB6- OCL, ILT. Canton Is.: KF6- JEG. Baker Is.: K6- LEJ, NYD, OJI, OQE, MVA, QHU, CGK, MZQ, ILW, OCM, BNR. The East. China: XU- lA, lB, 5W, 6PL, 7HV, SAM, SRB, SZA, SRJ, SRP, SMY, OA. Japan: J- 2CS, 2NG, 2KN, 2NQ, 2XA, 7CB. D.E.I.: PK- lDM, lMF, lOG, 2LZ, 3GD, 3MP, 3RP, 4KS. Philippines: KA- lFG, lCS, lCM, lCW, lAC, lAG, lAP, lJP, lGC, lGX, lDL, lAF, lLZ, lGS, lME, lKF, lOZ, lJG, lBB, lBH, lER, lGE, ISM, 3BW, 3KK, 3RA, 4RF, 4LH, 7EF, 7FV, 7RF. Reports Acknowledged. * Mr. W. M. Chapman (Kensington, N.S.W.): Many thanks for very comprehensive report. Yes, that refer- ence in the last issue to South African amateurs remaining on the air after November 1 was wrong. The new Russian stations are certainly difficult to follow. Will see what can be done about those mystery stations you mention. Mr. A. · T. Cushen (lnvercargill, N.Z.): Report to hand. Will look forward to some real DX loggings from you in the new year when you instal that new receiver. Mr. W. E. Bantow (Edithvale, Vic.): Pleased to receive such an interesting report. Would be pleased if you will check up on station on 6110kc., listed as VUC, Calcutta, as we believe this transmitter is not in use at present. Mr. 0. G. Washfold (Camberwell, Vic.): Your report was most certainly Page 34 of some use, and we hope to hear from you regularly. M.r. !D. J. Hastings (Brisbane, Ql'd.): Despite that QRM you seem to have little difficulty in logging some very fine DX on 2-0 metres. OQ5AB, PY2AR and PY2SN are certainly real catches. Mr. J. C. Taylor (Hurstville, N.S.W.): Many thanks for list of 10 and 20 metre loggings. Your Sunday morning sessions on 10 are getting .results, CE2AC being a fine logging. Mr. J. Ferrier (Coleraine, Vie.): Many thanks for photo. of shack. U.H.F. conditions have certainly been most disappointing. Mr. H. I. Johns (Nelson, N.Z.): Thanks for yet another fine report. Conditions in N.Z. seem a good deal better than they are in our locality, especially on 49 metres in the afternoon. The Month's * Loggings. In future, stations not listed in this section in the previous issue will be indicated by an asteri;;k (*). South America. Peru. This stat.ion is hearcl occasionally opening at 11 p.m., but, more often than not, it is inaudible on account of Q.RM. OAX5C, 9·350kc., 31.95m., lea: Now heard only on Sundays; better signal in N.Z. OAX4J, 9340kc., 32.12m., Lima: Heard fairly regularly still; early mornings around 7 a.m., and on Sunday afternoons till closing at 4 p.m. OAX4Z, 6.077kc., 49.3'/m., Lima: Heard in the late afternoons in N.Z.; also believed to have been testing around 9 p.m. Ecuador. HCJB, 12460kc., 24.08m., Quito: This well-known station has had a fresh lease of life and is again putting in a very fine signal around 10 p.m. (Chapman). heard in N.Z., closing after 3 p.m. Colombian Republic. "HJFK, 9740kc., 30.8111., Pereira: New South American station heard with good signal from 10 p.m. As is usual with these stations, the first half-hour's transmission is mainly news in Spanish. Chile. CB-960, 9600kc., 31.25m., Santiago: Heard quite well from 10 p.m. nightly. Brazil. been heard here lately, it is reported from N.Z., opening at 7 a.m. with a fair signal. Argentine. Aires: Still heard weakly on some mornings; best when it opens earlier at 7 a.m. on Saturdays. Uruguay. CXA-8, 9640kc., 31.12111., Colonia: Only Uruguayan station reported this month. ;Heard weakly on Sundaysboth afternoon and evenmg. Central America And West Indies. Guatemala. TGW A, 15170kc., 19.78m., Guatemala City: Now being heard at good strength in the early mornings-best around 7 a.m. on Mondays (Washfold). TGW A, 9685kc., 30.96m., Guatemala City: Best during special DX programmes on Sunday afternoons. Also on weekdays, closing between 2.30 and 3 n.m. (Washfold, Johns). noise-level. City: Another Sunday afternoon station; best around 5.15 p.m. Costa Rica. TIPG, 96I.5kc., 31.21m., San Jose: Still very strong from 10 p.m. TIL8, 6.165kc., 48.66m., San Jose : Also opens at 10 p.m., but not nearly as good as a few weeks ago. Panama. HP5A, 11700kc., 25.64m., Panama City: Still very erratic, nut sometimes at good strength after 10 p.m. (Chapman). HP5J, 9590kc., 31.28m., Panama City: Fair signal from 10 p.m. City: Good old regular, opening with waltz. Cuba. (Once again we would remind you that the following frequencies were correct at time of writing, hut will probably be out of date by the time they appear in print). sometimes in the early morning. COCM, 9850kc., 30.46m., Habana: Heard irregularly from l1 p.m. COCH, 9437kc., 31.Sm., Habana: Weakly at nights,. but spoilt by morse QRM. COBC, 9·350kc., 32.08m., Habana: As is mentioned elsewhere, this station has changed its frequency. Back to old channel from 99S.5kc. Opens with fair signal at 9.55 p.m. COBZ, 9030kc., 33.32m., Habana: Irregular; a weak signal on occasions around 11 p.m. OOCQ, 8850kc., 33.9m., Habana: Perhaps the best of the Cubans at present; from around 9.50 p.m. .
 * OAX4T, 9556kc., 3.i..38m., Lima:
 * HC2('W, 9135kc., 32.84m., Guayaquil: This unusual station is being
 * PRA-8, 6015kc., 49.87m., Pernambuco: Although this station has not
 * LRA-1, 9690kc., 3o.96m., Buenos
 * TGWB, 6486kc., 46.25m., Guatemala Gitv: Now harder to log on Sunday afte.rnoons on account of high
 * TG-2, 6195kc., 48.4m., Guatemala
 * HP5K, 6005kc., 49.96111., Panama
 * COGF, 11800kc., 25.42m., Matanzas: Heard weakly from 11 p.111. and

Dominican Republic. City: Heard just below HCJB, but not nearly as loud as that station. Scheduled to open at 9.40 p.m. North America. Mexico. Sunday afternoons. (Chapman). XEWW, 9503kc., 31.57m., Mexico City: Very reliable station. Heard daily till around 4 p.m. with fairly strong signal. Reported at good strength in N.Z.; Sundays, till closing at 4.30 p.m. (Johns). United Stat.es. WCBX, 21570kc., 13.9lm., New York: Fairly strong signal on some nights around midnight. (Chapman). WPIT, 21540kc., 13.93m., Pittsburgh: Heard occasionally at night around 10 p.m., though GSJ and GST tend to blot it out. WNBI, 17780kc., 16.87m., Bound Brook: Very nice signal in the early morning, best between 7 and 8 a.m. Also heard during forenoon, but hard to follow because of bad fading. (Bantow, Johns). Brook: Not heard in our locality but reported from Sydney with weak signal from 11 p.m. (.Chapman). WGEA, 15330kc., 19.56m., Schenectady: Good early morning station, with steady signal till 8 a.m. (Chap- man, Bantow). KGEI, 153·30kc., 19.56m., San Francisco: Very weak now and erratic; around noon. Heard on some mornings around 7 a.m.; used alternatively with WRUW, 15130kc. WCBX, 15270kc., 19.65m., New York: Still another early morning American station, closing M 6.30 a.m. Erratic, but signals very strong on some mornings. WPIT· 15210kc., 19.72m., Pitts- burgh: Fairly strong signal around midnight. "'WRUW, 15130kc., 19.83m., Boston: Nice strong signal on some mornings, with same progr:1mme as WRUL on 25 metres. Closes at 8 a.m. (Chapman). KKZ, 13690kc., 21.91m., Bolinas: Used for special relays to Hawaii on Sunday afternoons. KKQ, 11950kc., 25.lm.,Bolinas: Also
 * COJK, 8685kc., 34.54m., Camaguey: Heard once or twice of late, opening just before 10 p.m.
 * HllN, 12486kc., 24.03m., Trujillo
 * XEWW, 15160kc., 19.79m., Mexico City: Heard with a fair signal on
 * XEBT, 6000kc., 50m., Mexico City:
 * WRCA, 17780kc., 16.87m., Bound
 * WCAB, 15270kc., 19.65m., Philadelphia: Another early morning station, heard best around 8 a.m. (Chapman).
 * WRUL, 15250kc., 19.67m., Boston:

used for special relays on Sundays, and sometimes on week days around 3 p.m. (Chapman). WPIT, 11870kc., 25.?6m., burgh: Regular mormng around 7 a.m., with good (Bantow). P1UFstation signal WCBX, 11830kc., 23.36m., New York: Very strong signal from 7-9 a.m.; news in severni languages. WRUL, 11790kc., 23.43m., Boston:

Good signal till closiPg at 8 a.m. (Chapman). WRUW, 11730kc., 25 58rn., Boston: Used on some :nr,rning-,;; opening with a fairly strong signal :it 8.30 a.rn. (.Cushen). WRCA, 9670kc., l 0 3m, Hound Brook: Heard w!th weak signal in the afternoons, closing· a.; 4 p.m. (Chapman). WCAB, ;:)590ke, 31.2>\m., Phikdelphia: Fair signal t1!l closing '~ .5 p.m.; news just before signing off. (Chapman, Washfold). WBOS, 9570kc., 31.35m., Boston: Strong afternoon station; closes at 5 p.m. WGEA, 9550kc., 3l.41m., Schenectady: Barely audible in the mornings from 8.15 a.m. WGEO, 95·30kc., 31.48m., Schenec

tady: Opens at 6 a.m. with strong signal. (Chapman, Bantow, Johns). KGEI, 9530kc., 31.48m., San Francisco: Heard from 4 p.m.; and also from 10 p.m. when QRM from JZI is bad. (Chapman). from 3-4 p.m. Sundays in N .Z. Very weak in our locality. (Johns). WCBX, 6120kc., 49m., New York: Weakish signal till 5 p.m. WLWO, 6060kc., 49.5m., Cincinnati: Heard fairly well on some afternoons; best on Sundays when on till .5.30 p.m. Also at night around 10 p.m. •:19.65m., Miami Beach: Reported from N.Z. with strong signal on Sundays at 3.30 p.m. (Johns). Reported from N.Z. on special test with TG-2, Guatemala. (Cushen). AFRICA. Kenya Colony. VQ7LO, 6083kc., 49.31m., Nairobi: Consistent early morning station; heard best towards close after 5 a.m. (.Chapman). Ethiopia. 12AA, 9650kc., 31.09m., Ababa: Good signal around call was previously IABA. Canary Is. Addis 2 a.m EAJ-43, 10360kc., 28.96m., Teneriffe : Hard to log now; at times just audible around 6 a.m. Algeria. TPZ-3, 8960kc., 33.48m., Algiers: Quite a good signal until closing at 7 a.m. Mozambique. strength from N.Z.; from 8 p.m. on Sundays, with religious service. (Johns). Madagascar. m., Tananarive : Quite good on 1-2 a.m. transmission, opening, of course, with the "Marseillaise." Tananarive : Same time and same programme as the 9695kc., transmitter. South Africa. Have found this station difficult to log after midnight. *ZRL, 96.06kc., ·31.23m., Klipheuval: Also heard only once or twice, around 2 a.m. Fairly good signal from 3 a.m.; closes at 7 a.m. on week-days. Heights: Just fair till closing at 6.30 a.m.
 * WPIT,__ 6140kc., 48.86m., Pittsburgh: Reported with excellent signal
 * WBKM (ex-W4XB), 6040kc.,
 * WRUL, 6040kc., 49.65m., Boston:
 * CR7BH, 11718kc., 25 6m., Lourenco Marques: Reported at good
 * Radio Tananarive, 9695kc., 30.95
 * Radio Tananarive, 6060kc., 49.5m.,
 * ZRO, 9752kc., 30.77m., Durban:
 * ZRK, 6097kc., 49.2m., Klipheuval:
 * ZRH, 6007kc., 49.94m., Roberts

' *ZNB, .5900kc., 50.85m., Mafeking, British Bechuanaland: May be heard daily except Mondays, 4-5.30 a.m. OCEANIA. New Caledonia. FK8AA, 6122kc., 49m., Noumea: Still heard at good strength in the late afternoons. AUSTRALIA. YLR-3, 11880kc., 25.z:>m., Lyndhurst: Used in - the mornings and afternoons. (Washfold). New station heard testing at good strength; to be used in new overseas service. (Washfold). VLR, 9580kc., 31.32m., Lyndhurst: Replaces VLR-3 for night session. (Washfold, Johns). Tests heard on this frequency. (Washfold). THE EAST. Philippine Is. New frequency for KZRH; heard at good strength; scheduled from 7 p.m.- 1 a.m. (Bantow, Washfold). KZRM, 9570kc., 31.35m., Manila: Good night station; very reliable and excellent signal. (Chapman, Washfold, Bantow). KZIB, 9500kc., 31.58m., Manila: Also a good signal from 8 p.m.; widely reported at good strength. (Washfold, Bantow, Chapman). I\ZRM/KZEG,/KZRF, 6140kc., 48.86m., Manila: Still heard well; this transmitter uses all of the calls mentioned. (Chapman, Bantow, Washfold). KZRH, 6110kc., 49.lm., Manila: Also heard at night. (Chapman). KZIB,.. 6040kc., 49.6.7m., Manila: Not as loud as other P.L stations on this band. (Chapman). Mafaya. ZHP, 9690kc., 30.96m., Singapore: One of the most reliable signals to be heard; best between 10 and 11 p.m. (Bantow, Chapman, Washfold). . · ZHJ, 6080kc., 49.3m., Penang: Hard to hear now; but from N.Z. it is re- ported at good strength. Announces in English from 9.-30-11.30 p.m.; power increased to lkw. (Johns). India. VUD-3, 15290kc., 19.62m., Delhi: Heard on occasions after mid-day and in late afternoon. (Bantow). VUD-18, 4960kc., 60.48m., Delhi: Very good indeed at present. from 10.30 p.m.; maintains strength till close at 3.30 a.m. (Bantow, Chapman). VUD18, 4960kc., 60.48m., Delhi: Note new call. News at 10.30 (Chapman). VUM-2, 4920kc., 60.98m., Madras: Just fair .. (Chapman). VUB-2, 4880kc., 61.48m., Bombay: Jm;t audible. (Chapman). VUC-2, 4840kc., 61.98m., Calcutta: Fairly strong. (Chapman). Page 36 Burma. XYZ, 6007kc., 49.94m., Rangoon: Not very strong now, best in the early a.m. (Chapman). French Indo-China. Radio Saigon, .. 11780kc., 25.47m., Saigon: Exceptionally strong signal from 9 p.m. Replaces the 49m. transmi.tter as regular evening station. Power increase to 12kw. re- ported. (.Chapman, Bantow, Washfold, Johns). m., Saigon: Testing on new frequency. Heard nightly till after midnight. Saigon: Reported weakly in N.Z. from 11.30 p.m., opening with the "Marseillaise." Radio Saigon,.. 6.116kc., 49.05m., Saigon: Believed .to have gone off the air on December 10; replaced by 25- metre station. (Bantow, Johns). Hong Kong. ZBW-3, 9525kc., 31.49m., Hong Kong: Regular strong signal at night. (Chapman, Bantow, Washfold). China. XGOX, 15190kc., 19.75m., Chungking ( ? ) : Excellent signal at night. XGOY, 11900kc., 25.21m., Chunking (?) : Very reliable station; heard early morning and at night. (Cushen, Chapman, Bantow, Washfold). XMHA, 11850kc., 2.5 .32m., Shanghai: Quite good at night. XGOK, 11820kc., 25.38m., Canton: Fairly regular at night. XP.SA, 7000kc., · 42.Sm., Kweiyang: Good signal nightly. (Bantow). XO.TD, 6880kc., 43.6m., Hankow: Still some doubt as to call, but majori.ty of overseas sources favour XO.TD and not XJOD. Call doubtful; heard in N.Z. Mnm~hukuo. MTCY, 11775kc., 25.48m., Hsinking: Good morning session from 7 a.m. (.Chapman). MTCY, 6125kc., 48.98m., Hsinking: Used at night. (Bantow). Thailand. HSSPJ, 9510kc., 31.55m., Bangkok: Not on the air every night, but always good signal when logged. heard weakly on occasions. Taiwan. · JIE-2, 9695kc., 30.95m., Tyureki: Same programme as JFO, relaying JF AK. Hard to hear. JFO, 9635kc., -31.13m., Taihoku: Never very loud, but usually audible at night. · · .TIE, 7295kc., 41.13m., Tyureki: Fair signal around midnight. (Chapman). Japan. JZK· 15160kc., 19.79m., Tokyo: Good strong signal; best at night. (Chapman). JZI, 11800kc., 25.42m., Tokyo: Best from 10 p.m. at night. (Chapm<:c Johns). JVW-3, 11720kc., 25.6m., Tokyo: Fair from 8 p.m. (Chapman, Bantow, Washfold). JLG-3, 11705kc., 25.63m., Tokyo: Also heard at night. JZI, 953.5kc., 31.47m., Tokyo: At night from 10 p.m.; but makes a good job of interfering with KGEI. JVW, 7258kc., 41.3,1m., Tokyo: This new station is still heard well fron: 6-7 a .m. (Chapman). !Dutch East lndi'es. YDC, 15150kc., 19.Sm., Bandoeng: This station puts on a really entertaining programme at night. (Chapman, Cushen, W ashfold). PLP, llOOOkc., 27.27m., Bandoeng: Relays YDC; fair. (Chapman, Washfold). PMN, 10260kc., 29.24m., Bandoeng: As PLP; fair. (Washfold). YDB, 9550kc., 3l.41m., Bandoeng: Quite good at midnight. YDX, 7220kc., 41.55m., Medan: Strong, native programme. PMH, 6720kc., 44.64m., Bandoeng: Very loud, native programme. (Chapman). YDD, 6.045kc., 49.63m., Bandoeng: Fair some nights. EUROPE. Sweden. SBP, 11705kc., 2.5.63m., Motala: Heard some mornings; and reported from N.Z. as heard at 8 p.m. on Sundays. (Johns). SBT, 15155kc., 19.79m., Motala: Reported with good signal around 7 a.m. in South Australia. Yugo-Sfavia. New frequency for Belgrade; reported from N.S.W. and Qld. in early morning. YUC, 9505kc. ,3L56m., Belgrade: Not as loud as formerly in early mornings. (Chapman). Turkey. TAP, 9465kc., 31.7m., Ankara: Heard well every morning; also now on the air from 10 p.m. on weekcrn'ls. (Bantow). Portugal. CSW-6, 11040kc., 27.17m., Lisbon: Good signal till 6 a.m. or 7 a.m. (Chapman). · CSW-7, 9740kc., 30.0Sm., Lisbon: Seems to be opening at either 6 or 7 a.m., with nice, clear signal. Belgium. ORK, 10330kc., 29.04m., Ruysselede: Regular signal in early morning till 6 a.m. (Chapman). Holland. PCJ-2, 15220kc., 19.71m,, Huizen: Best in special session for Australasia, Tuesdays, 6 p.m. · PC.J, 9.590kc., ·3l.28m., Huizen: Fair ~ignal at 6 a .JY.. (.Chapman). ·PHI-2, 17770kc., 16.88m., Hu1zen: Fair signal some nights. Spain. . EAQ, 9860kc., 30.43m., Madrid: Only weak in early morning. The Australasian Radio World, January 1, 1940.
 * VLW, 11830kc., 25.36m., Perth:
 * VLW, 6130kc., 48.94m., Perth:
 * KZRH, 9660kc., 31.06m., Manila:
 * Radio Boy-Landry, 9680kc., 30.99
 * RadiO Volonte, 7100kc., 42.25m.,
 * XHHB, 7970kc., 88.5m., Shanghai:
 * HS6PJ, 19020kc., 1·5.77m., Bangkok: Used on Mondays from 11 p.m.;
 * YUG, 15240kc., 19.68m., Belgrade:

Norway. LKV, 15170kc., 19.78m., Osio: Still heard. from about 2 a.m.; weakens a good deal by 6 a.m. (Chapman). Switzerland. ¥HBO, 1l402kc., 26.32111., Geneva: Th~s League station is again on the air; heard one Sunday at 7 p.m. (Chapman). Vatican City. City: May be heard at times just before midnight. U.S.S.R. · .*New station, call and location un- known, on 9680kc., 30.97m. Scheduled from midnight-6.20 a.m.; very loud on opening. (Chapman). Used irregularly; very loud. (Chapman). 52.4m. .Heard nightly at good strength. at midnight. Also logged: RV-96, on 19.47, 19.75, 31.51 and 49.75m.; RAN, RNE and RKI, 19.95m. France.
 * HVJ, 15120kc., 19.84m., Vatican
 * New station on 11640kc .. 25.77m.
 * New station on approx. 5710kc.,
 * RKI, 7520kc., 39.89m., Moscow: Not used regularly; heard sometimes
 * Paris · Mondial. 11843kc., 25.35m.,
 * Paris: New lOOkw. station; strong

signal in early morning. (Bantow). Paris Mondial, 9680kc., 30.99m., Paris: Much weaker now in afternoons. (Bantow). Now heard again in late afternoons. Also logged: TPA-2, TPB-3, TPB-6, TPA-4, TPB-11 (41.21 and 25.23m.) and TPB-12. Italy. New station, heard testing at 1 a.m.; very strong. Also a new station, testing around midnight. Also logged: 2R0-3, 2R0-4, 2R0-9, 2R0-6, 2R0-8, 2R0-12, IRF, IQY, IQA. England. The best stations on the Daventry transmissions are set out below:- Transmission 1: Early, GSD; after 6 p.m., GSF and GSD. Transmission 2: Before midnight, GSJ; after midnight, GSF. Transmission 4a: GS.O. Transmission 4b: GSB and GSD. Transmission 5: Signals from all ~tations poor. ,,rans mission 6: Very poor
 * TYA-2, 9040kc., 33.19m., Paris:
 * 2R0-15, 11760kc., 25.5m., Rome:
 * 2R0-5, 15170kc., 19.78m., Rome:

Letter~Box Sectiort. Joseph A. Bull, Caron, W.A.: Thank you for interesting letter and kind offer of assistance. Have written you re latter matter. H. Whyte-Meach, Sydney, N.S.W.: Pleased to hear your views on con- test. Am writing you further re matters mentioned. Tom Cowls, Timaru, N.Z.: Received your cheery note. Am forwarding information required. Eric W. Watson, Christchurch N.Z.: Pleased to get your views o~ club management. Sorry I could not ~ssist with publicity. Will write you m near future. R. A. KeUy, .. Wellington, .. N.Z.: Thank you for notes. Have sent you information by separate letter. M. E. Tribe, Inglewood, N.Z.: Sorry to hear about your set. Write again. G. E, Notley, Moonah, Tas.: That is the sort of letter I want. Send me a monthly list of loggings. Merv. A. Branks, Invercargill', N.Z.: Merv. is B.C. Editor of the N.Z. "DXtra." Thanks for letter, Merv. Not€d source of QRM. Especially bad at nights, they tell me. Hi! Hi! Ray Simpson, Concord, N.S.W.: Can't agree B.C. DX is difficult. Write again. N.Z. DX 9lub: We are much indebted to this club for its kind offer of assistance from time to time and all members of this cluub are eligible to compete .f ?r the Pacific Trophy. Persons reqmrmg further information should write to Merv. A. Brank>; 5 Dublin Street, Invercargill, N.Z. ' Owing to the poor reception from Asia at the moment, it is proposed to publish a European list in three parts. Anyone desiring information should write to me C/- 188 Chapel Street, Prahran, Victoria. Return postage is unnecessary. ,. Here is Part I. of the European 11st:- 536kc., lOkw., Bolzano,. litaI•y: Identifies with whistle or song of a nightingale. 536kc., 50kw., Wilno, Poland: Signal was call of cuckoo and, if relaying from Warsaw, they superimposed the letter "W" over the programme being relayed. Signal now, if still on air, would probably be same as German stations. 546kc., 120kw., Budapest, Hungary: Interval during programmes; a phase of nine notes in two-part harmony, four notes repeated, followed by
 * Inter-Club Notes.
 * Best Stations Of The Month.

initial notes, thus: G sharp, BABG sharp, BABG sharp. Call, "Hallo. Itt Radio Budapest," followed by "Hallo! Hier Budapest" and "Voici le poste radiophonique, Budapest, Hongrie." 556kc., lOOkw., Beromunster, Switzerland: Interval signal: Cl·ock ticking. Male announcer. "Hallo, hier Schweizerischer Landessender, Beromunster." Relays to other Swiss stations. 565kc., lOOkw., Athlone, Eire: Dual announcements in Gaelic and English. Identification signal not known. 565kc., 3kw., Catania, Italy: See Bolzano, 536kc. 565kc., lOkw., Klaipeda, Lithunia: Not known to make English announcements. Identification signal unknown. 565kc., 3kw., Palermo, litaly: See Bolzano, 536kc. 574kc., lOOkw., Stuttgart, Germany: Uses a metronome (ticking 200 times per minute) during intervals in programme. Signs with "Heil Hitler." 583kc., 20kw., Alpes-Grenoble, France: Announces only in French. ldentification signal unknown. 583kc., 50kw., Madona, Latvia: No information available. Should be loggable in Australia. 592kc., lOOkw., Vienna, Germany: Same as Stuttgart, 574kc. 60lkc., 15kw., Athens, Greece: No particulars available. 601kc., lOkw., Sunsdvall, Sweden: See Stockholm, 704kc. 610kc., 20kw., Florence, Italy: See Bolzano, 536kc. 620kc., 15kw., Brussells, Belgium: All announcements in French. Gall "Ice, Bruxelles, emissions d'essais," repeated between sessions and most items. 625kc., lOkw., Kourbyshev, U.S.S.R.: Does not feature English ses~io11. Closes with "Internationale." 629kc., 20kw., Christiansand, Norway: No information available. 629kc., 20kw., Lisbon, Portugal: English sessions unlikely. 629kc., 20kw ., Trondelag, Nor way: No information available. 638kc., 120kw., Prague, Germany: Announcer mys, "Halo! Radio Praha Vygila" in Czech, German, French and English. 648kc., lOkw., Petrozavodsk, U.S.S.R.: See 625kc. 658kc., lOOkw., Cologne, Germany: See Stuttgart, 574kc. 668kc., 70kw., North Regional, Gt. Britain. 677kc., lOOkw., Sottens, Switzerland: Male and female announcers. "Allo ! Allo ! lei Radio Suisse Roman de Sottens". ("Geneve," "Lausanne"). Page 38. 686kc., 20kw., Belgrade, Yugo8lavia: Announces in German and in Italian, as well as in Croat. G95kc., 120kw., Paris, France: Identification signal unknown but announces frequently as "Radio Mondiale." 704kc., 55kw .. , Stockholm, Sweden: Call, "Stockholm Rundradio," or "Stockholm Motala," if Motala i3 relaying. Call is repeated. Relays to r.everal stations throughout Sweden. 713l;:c., 120kw., Rome, Italy: Signal, belis of Rome and whistle of birds. Announcer says, "Radio Roma," or "Radio Roma-Napoli." 722kc., lkw., Frederikstad, N orwa·y : No information available. 722kc., 17kw., Hilversum 2, Hol- 722kc., lOkw., Kharkov, U.S.S.R.: See 625kc. 73lkc., 3kw., Madrid, Spain: No information available. 73lkc., 5kw., Seville, Spain; No information available. 7 40kc., lOOkw., Munich, Germany: See 574kc. H9kc., lOOkw., Marseilles, France: No information available. 7-19kc., lkw., Pori, Finland: See Hel!"inki, 895kc. 758kc., 120kw., Katowice, Poland: Very doubtful if still on air. 767kc., 60kw., Burghead, Great Britain. 776kc., 250kw . ., Sortavala, Finland: See 895kc. 776kc., lOkw., Italino, U.S.S.R.: See 625kc. 776kc., 120kw., Toulouse, France. 785kc, 120kw., Leipzig, Germany: See 574kc. 795kc., 7.5kw., Barcel'ona, Spain: No information available. 79·3kc., 50kw., LwG•W, Poland: Probably off air now. 80,Jkc., 5kw., Penmon, Anglese;;, Great Britain. 804kc., 70kw., Welsh Regional, Great Britain. 814kc., 50kw., Milan, Italy: See Bolzano, 536kc. 823kc., 12kw., Bucharest, Roumania: Uses metronome (160 beats per minL1te ). 832kc., 35kw . ., Kiev 2, U.S.S.R.: See 625kc. 832kc., 400w., Rueil-Malmaison, France. 832kc., lOkw., Stavanger, Norway: H::>.s been verified by Australian dx-ers. 841kc., lOOkw;, Berlin, Germany, See 574kc. 850kc., lkw;, Porsgrund, Norway, 850kc., -, Saragossa, Spain.· 850kc., lOOkw., Sofia, Bulgaria.; 850kc., 3kw., Valencia, Spain. 859kc., lOkw., Simferopol, US.S,R.: See 625kc. 859kc., lOOkw., Strasbourg, France. 868kc., 50kw., Poznan, Poland: Probably off air now. 877kc., 70kw., London Regional, Great Britain. 886kc., 15kw., Graz, Germany: See · Stuttgart, 574kc. 886kc., 15kw., Linz, Germany: As for Graz. 895kc., lOkw., Hel'sinki, Finland: Male and female announcers. All an- nouncements and calls given in Swedish and Finnish. May not be transmitting now. Most Finnish stations relay Helsinki. 895kc. ., 1.5kw., Limoges, France .. Should any reader be able to furnish further information regarding stations listed above, we would be very grateful to receive such information. Listening Times; The American and Europeans are now booming in. Best times for DX are:-·11 p.m.-1 a.m. (Yanks) and 2.30 to 6. a.m. (Europeans). The changeover to summer conditions has proved rather trying because of the static barrage. DX, however, has been exceptionally good, and many FB catches have been re- ported. DX is better than in January, 1939, and it looks like a bumper year for Europeans between now and early April, because many stations are opening earlier and closing later be- cause -of present European politics. We may yet again hear the broadcast of the bombing of cities by air, such as we experienced during the Spanish conflict in 1936. QSL Exchange Bureau. The following readers would like to exchange QSL cards with members of the All-Wave All-World DX Club:- A. E. Watson, Lloyd St., Murtoa, Victo1fa. John H. Lilburne (AW.541DX), Post Office, M urtoa, Victoria. Percival Roy Horan (AW531DX), George St., Bowen, Nth. Q'land. L. R. J. Knighton (A W298DX), 245 Armagh St., Christchurch, New Zealand
 * 1,md: Gall, "Hier, Hilversum, Holland," coupled with name of broadcasting company providnig the broadcast.
 * Review Of Conditions and

P.37 - Broadcast 'Band DX Notes
Broadcast Band DX Notes

Conducted by Kevin A. Crowley

Station Notes And News. Australia: The P.M.G.'s Department has notified us of the following changes:-2RG, Griffith, to 1070 kc., power increase to 200 w.; 2XL, Cooma, to 920kc.; 3UL, Warragul, to 880kc.; 4VL, Charleville, to 920 kc.; 5MU, Murray Bridge, to 1460kc.; 7DY, Derby, to 1450kc.; 7UV, Ulverstone, to 900kc.; 2BH, Broken Hill, to 570kc.; 4AY, Ayr, to 970kc.; 2DU, Dubbo, power to 150w.; 4RO, Rockhampton, power to 200w.

America: List of new call signs and frequency changes will be published next month.

Specials. American stations are the best midnight scoops at the moment. Listen for them between 11 p.m. and 1 a.m. Listen for these. They are very easy loggings at present:- 600kc., KFSD, San Diego. 610kc., KFRC, San Francisco. 640kc., KFI, Los Angeles. 680kc., KPO, San Francisco. 780kc., KEHE, Los Angeles. 790kc., KGO, San Francisco. 900kc., KHJ, Los Angeles. 1010kc., KQW, San Francisco. 1050kc., KNX, Los Angeles. 1300kc., KSL, Salt Lake City.

Contest Notes. The Editor of "Radio World" has kindly donated three twelve-month subscriptions to "R.W.'' as additional prizes in the Pacific Trophy contest. Dx-ers will best show their thanks by entering wholeheartedly into the contest. Allocations of these prizes is as follows:-(1) Best Australasian log; (2) best Indian log; (3) best Chinese log. Receiver, location and time of reception will all be considered in awarding these prizes.


text:
Planet Earth/1h. Milankovitch cycles: Oscillations in Earth’s Spin and Rotation

"The heavy iron door closed behind me....I sat on my bed, looked around the room and started to take in my new social circumstances… In my hand luggage which I brought with me were my already printed or only started works on my cosmic problem; there was even some blank paper. I looked over my works, took my faithful ink pen and started to write and calculate… When after midnight I looked around in the room, I needed some time to realize where I was. The small room seemed to me like an accommodation for one night during my voyage in the Universe."

Milutin Milanković: The Imprisoned Scientist
Arrested and imprisoned while returning from his honeymoon, in summer of 1914, Milutin Milanković found himself alone in his prison cell. As a successful engineer and expert in concrete and bridge building, Milutin was wealthy, in love with his new wife, and hopelessly obsessed about a cosmic scientific program that wrestled his mind even as he was being imprisoned. Milutin was born in Serbia and had taken a position as the Chair of Mathematics across the border in the Austro-Hungarian city of Budapest, the same year that Gavrilo Princip, a Serbian, assassinated the heir to the Austro-Hungarian throne, Archduke Franz Ferdinand. The assassination would plunge the globe into the first World War. And as a Serbian returning to the Austro-Hungarian Empire, Milutin was arrested and placed in jail. His new wife, Kristina Topuzovich, implored the authorities to let her husband go, but as the hostilities between nations escalated during the summer, his chances of release diminished. Milutin Milanković was singularly obsessed with a problem in science, and it had to do with the motion of the Earth through space. In the years leading to 1914, scientists had discovered that the Earth had experienced large widespread Ice Ages in its recent past. Cold periods of time which had lengthened glaciers, carved mountains, and deposited large boulders, which covered the landscape of northern Europe and North America in giant ice sheets. Geologists around the Northern Hemisphere had discovered strong geological evidence for these previous episodes of ice ages, yet climate scientists had yet to discover a reason why they had occurred. Milutin had wrestled with the idea, and wondered if it had to do with long term cycles in Earth’s orbit.

Earth’s Tilt Causes the Seasons
The winter and summer months are a result of Earth’s tilt of 23.5 degrees, such that as Earth rotates around the Sun during the months of June, July, and August the Northern Hemisphere points toward the sun, lengthening the Solar Day. While in December, January, and February the Southern Hemisphere points toward the sun lengthening the day in the Southern Hemisphere. Milutin wondered if there was a similar but much longer orbital cycle with Earth that would cause a long-term cycle of ice ages.

Earth’s Precession
Before his imprisonment, Milutin begun studying something called Earth’s Precession. For nearly two thousand years, astronomers mapping the stars had made note of a slight shift in the position of stars in the night sky. The position of Earth’s axis relative to Polaris (the North Star), appears to move in a circular path in the night sky, which is estimated to complete a circle in 25,772 years. This odd observation also helps to explain the peculiar fact that the Sidereal Year, when a star returns to the exact same position in the night sky after a full rotation around the sun and the Solar Year (also called a Tropical Year) when the sun returns to the exact same position in the day time sky (noon between two summer solstices) is about 21 minutes shorter. This 21 minutes shorter Solar Year reflects this slight wobble with Earth’s orbit, which was called a precession cycle. After 25,772 years the position of the stars and the solstice will return to their original starting positions. The best way to explain the axial precession cycle is to watch a spinning top or gyroscope, which tends to wobble during its spin, such that the axis of the spin rotates in a circle when viewed from above. Milutin realized that this cycle could be the clue to unlock the reason for the ice ages in Earth’s past, because it was an example of a long-term orbital cycle, however it was not the only one.

This precession of Earth’s orbit was first recognized with the vernal and autumnal equinoxes, called the Precession of the Equinoxes. As the Earth spins, the Sun’s path forms a great-circle referred to as an ecliptic around the Earth. The celestial equator is a great-circle projecting out from Earth’s equator onto the starry night sky. The angle between these two great-circles is 23.5°, the tilt of the Earth’s axis. When these two great circles intersect, determined by observing the rising sun relative to the background stars, defines the equinox. The equinox occurs when the Earth’s tilt is perpendicular to the direction toward the sun, and the days are equal length across the Earth. This occurs around March 21st and September 23rd. However, astronomers noticed that the background stars that forecast the coming of the equinox was shifting. Resulting in a Precession of the Equinoxes in the night sky. Of course, this is a result of the axial precession, which shifts the ecliptic relative to the celestial equator, as well. Milutin realized that during this cycle, the axis of the Earth would project more toward the sun and further from the sun at different times of the year. For example, there would be a period of several thousand years when the North Hemisphere would wobble more toward the sun during the summer (making it hotter), and a period of several thousand years when the North Hemisphere would wobble away from the sun during the winter (making it colder).

Earth’s obliquity
Working with the University, Milutin’s wife arranged for Milutin to be transferred to the library at the Hungarian Academy of Sciences. He was forbidden to leave and was under guard during the War, but allowed to continue his research. Earth’s precession was not the only long-term variation in Earth’s orbit. The tilt of Earth’s orbit oscillates between 24.57° and 22.1°, with a current tilt of 23.43677° and is slowly decreasing. This shift in the tilt of axis completes a cycle about every 41,000 years. This is referred to as Earth’s obliquity. The first accurate measure of Earth’s tilt was determined by Ulugh Beg (الغ بیگ), who built the great Samarkand Observatory, in present day Uzbekistan. His calculation of 1437 CE was 23.5047°, indicating a decrease of 0.06783° over 583 years, indicating a complete cycle of 42,459 years for Earth’s obliquity. The oscillations in Earth’s tilt would result in more severe winters and summers during these long-periods of several thousand years when Earth’s tilt was greater. While in the library, Milutin pondered the effect of Earth’s changing obliquity on Earth’s climate and moved onto a third orbital variation.

Earth’s Eccentricity
The third long-term variation in Earth’s orbit that Milutin examined was the shape of Earth’s elliptical orbit around the sun. During this yearly orbit around the sun, the Earth is closest to the sun at the perihelion (which occurs around January 4th), and furthest from the sun at the aphelion (which occurs around July 5th). Mathematically we can define a term for circles called eccentricity. When eccentricity is zero, the circle will be a perfect circle, the difference between the distances across the widest part of the circle and the narrowest part of the circle is zero. If we define the circle as actually an ellipse, rather than a perfect circle, the difference between the widest part of the ellipse and the narrowest part of the ellipse will be greater than zero, we call this difference eccentricity.

To measure Earth’s eccentricity requires that we observe the daily path of the sun’s shadow for a full year and determine the precise time it reaches its highest point in the sky (shortest shadow each day). The difference from the local noon time, and when it is observed at the highest point in the sky will shift slightly through the year. This is because the Earth’s path relative to the Sun will have slight differences in velocity as Earth moves around the Sun over a year along this elliptical path. Sometimes the Earth will be slower, during the narrow width days, and sometime faster during the wider width days of the year. The differences in local noon time, and observed solar path can be used to determine Earth’s eccentricity, which is currently 0.0167. It is nearly a circle, but not exactly. Another way to measure the Earth’s eccentricity is to measure the width and shape of the analemma of the Sun each day of the year. This is the position in the sky each day that the sun reaches its highest point. The shape of the analemma is dependent on the elliptical path of the Earth around the Sun, and will result in a path looking like the figure 8 for eccentricity less than 0.045. However as Earth’s eccentricity approaches 0.045 or greater it will become more tear-drop in shape with no intersection.

Earth’s eccentricity oscillates between 0.057 and 0.005, which means that sometimes Earth will be more circular in its path around the sun, and sometimes more elliptical. When the eccentricity is greater, Earth will be further and closer to the Sun during those points in its orbit. In the Northern Hemisphere, the perihelion occurs in the winter, resulting in a milder winter, while the aphelion occurs in the summer, resulting in a cooler summer. When eccentricity is less, the winters and summers will be colder and hotter in the North Hemisphere, but the opposite in the Southern Hemisphere. However, the distance to the sun oscillates only several thousand kilometers, and has a fairly mild effect on climate. The eccentricity cycles between its extremes every 92,000 years, although it oscillates in an odd pattern because these changes in eccentricity are due to the interaction of Earth with other planets in the solar system, particularly Mars, Venus, and Jupiter, which pull and tug at Earth, stretching Earth’s yearly orbital path around the sun. The largest planets such as Jupiter and Saturn also tug on the sun. Hence astronomers define something called the barycenter of the solar system. A barycenter is defined as the center of mass of two or more bodies in orbit with each other. When the two bodies are of similar masses (such two stars) the barycenter will be located between them and both bodies will orbit around it. However, since the sun is much much larger than the planets in the solar cycle, the barycenter is a moving point orbiting near sun’s core. This is what causes the changes in eccentricity, as Jupiter and Saturn (and other planets) tug and pull on Earth and the Sun, causing the center of the solar system not to be exactly in the direct center of the sun.

The three major orbital influences on Earth’s climate
Milutin Milanković was released after the war, and applied his mathematical knowledge to better understand Earth’s past climate. He did this by looking at the mathematical summation of these three major orbital influences on Earth. By combining these three long-term orbital variations, he laid out a prediction for scientists to determine Earth’s oscillations with its climate over its long history. His publications and notes on Earth’s motion and its relationship to long-term climate was published in book form in 1941 in German, entitled Kanon der Erdbestrahlung und seine Anwendung auf das Eiszeitenproblem (The Canon of the Earth’s Irradiation and its Application to the Problem of Ice Ages). Milanković mathematically predicted oscillations of Earth’s climate and long-term cycles that have been verified repeatedly in ice core data, and ancient sedimentary rocks, which show these long-term cycles in Earth’s orbit, which today we call Milanković Cycles.