text:
Selected Essays/Forest of India

The word ‘forest’ is derived from the Latin word ‘fores’ which means ‘outside’. Thus, it must have always referred to a village outskirt, fence or boundary which might have included all cultivated as well as uncultivated land. Today, of course, forests refer to vast areas of land covered with thick vegetation, trees and animals dwelling within.

Climatic factors such as rainfall and temperature along with soil, determine the kind of natural vegetation that will be found in a particular place. Places that receive more than 200cm of annual rainfall have evergreen rain forests.

Areas receiving rainfall between 200 and 100cm have monsoon deciduous trees while drier deciduous or tropical savannah forests are found in areas receiving 50 to 100cm of rains per annum. Places which receive less than 50cm annually have only dry thorny found in different parts of the country. Ranging from tropical wet evergreen, tropical moist deciduous, tropical dry evergreen, sub-tropical dry evergreen, broad-leaved or pine, Himalayan dry temperate to sub- alpine and dry Alpine and other 126 kinds and sub-types of forests are found here. At the present the total forest and tree cover of the country is 78.92 million hectare which is 24% of the geographical area of the county.

Indian forests are also classified on the basis of statutes, ownership, composition and exploitability. The legal or administrative classification is done to protect forests against indiscriminate cutting of trees. The forests in India have been divided into (i) Reserved, (ii) Protected and (iii) Unclassified. The first two categories are permanent forests which are maintained for regular supply of timber and other forest products. They are also maintained to restore the ecological balance. The reserved forests in India cover about 54% of the total forest area of the country while 29% of the total forest area is protected.

The remaining 175 is the unclassified forest area which is mainly unproductive and unprofitable. Another classification is based on the ownership of forests. Most of the forests are owned by the Government through the means of its departments such as forests department etc. Some are owned by corporate bodies. A negligible 1% area is owned privately by states like Meghalaya, Odisha, Punjab and Himachal Pradesh.

An important type of forest in India is the village forests or Panchayat forests. These are the forests which are managed by local communities, keeping in mind the idea of sustainable development. Community forest management involves collaboration between villagers and NGOs.

The Rajaji National Park has been built on this model. Indigenous forest management refers to initiatives taken by villagers and the communities which share the responsibility of protection in turns. The ‘sacred groves’ are small communal forests, which are protected for their rare flora and religious importance.

There are other forests like production forests, which are maintained for commercial production. The other is social forestry, which supports the rural poor, who depend on forests for their livelihood. Agroforestry is a scheme where farmers carry out plantations of Eucalyptus, Casuarina, teak etc, on their agricultural land using irrigation and fertilisers to find a market for their produce. Forests make up for one of the major natural resources of a country. Their use in fuel, timber, and industrial raw material cannot be undermined. Bamboos, canes, herbs, medicines, lac, grasses, leaves, oil etc are all received from the forests. India has about 5000 kinds of variety of woods out of which more than 400 are commercially used. Hard woods such as teak, mahogany, logwood, ironwood, ebony, sal, greenheart, kikar, semal etc are used in making of furniture, tools and wagons. Soft woods such as deodar, poplar, pine, fir, cedar, balsam are light, durable and easy to work. Therefore, they are used in constructions and as raw material for making paper pulp. But unfortunately, 70% of the hard wood is burnt as fuel and only 30% is used commercially. On the other hand, 70% of soft wood is used in industries while 30% is used for fuel purposes. Thus, forests meet about 40% of the energy requirement of the country which includes 80% of the rural requirements.

Indian forests are one of the 12 mega-biodiversity regions around the world. The Western Ghats and Eastern Himalayas are among the biodiversity ‘hotspots’ of the world. India is home to 12% of world’s plants and 7% of Earth’s animals species. India also has one of the riches varieties of bird species. Indian forests and wetlands are the temporary abodes of many migratory birds. Many birds and animals are endemic to India. Moreover, forests help in the control of soil erosion and control floods to a considerable extent. Forests also check the spreading of desert through strong winds. They add humidity to the atmosphere which checks the spread of desert. The humus added to the soil increases the soil fertility and soothes the extremes of climate by reducing the heat in summers and the cold in winters.

Thus, keeping in mind their great use, forests should be conserved and protected in India. The Government has made many efforts to increase the forest cover in the country. The Ministry of Environment and forests is implementing a National Afforestation Programme (NAP) scheme with people’s participation, including involvement of non-government persons, rural and local people living in and around the forest areas to increase Forest and Tree Cover (FTC) in the country.

The scheme is being implemented through a decentralized mechanism of State Forest Development Agency (SFDA) at state level, Forest Development Agency (FDA) at forest division level and Joint Forest Management Committees (JFMCs) at the village level. In 1988, a New Forest Policy was introduced to maintain ecological balance, preservation of forests as natural heritage, prevention of soil erosion, check on the expansion of deserts, increase in the forest are to increase forest productivity and to propel a mass movement to achieve these objectives. Van Mahotsav was initiated in 1950 and the famous Chipko Movement stands as an example of the effect of people’s movement. In 1987, the Indian Council of Forestry Research and Education which was created was converted into an autonomous body called Forest Research Institute.

More recently, Arunanchal Pradesh set an example to the entire nation by achieving 70% afforestation.

title: Selected Essays/Forest of India


text:
Linux Basics

Chapters

 * 1) Introduction
 * 2) Types of Operating Systems (UNIX, Windows, Mac, Linux) [Stub]
 * 3) Fundamental conceptions in Linux (more important distributions)
 * 4) /Distributions for beginners/
 * 5) /Installation, bootloader/ [Stub]
 * 6) /Package management/ [Stub]
 * 7) /The structure of Linux/
 * 8) /Basic commands/
 * 9) /Graphical interfaces/
 * 10) /Terminals, command prompt, alias, history/
 * 11) /Archiving, mounting in depth/
 * 12) /User management/
 * 13) /User management (System administrator)/
 * 14) /Package management, process management/
 * 15) /Filesystem, permissions/
 * 16) /If you want to deal more with Linux/
 * 17) /Interesting stuff/
 * 18) Sources

License
CC-BY-SA 3.0 and GNU FDL 1.3 (the latter one because of the content of szit.hu and tldp.org), GNU GPL for the 2nd chapter's distribution descriptions.

Linux/Linux alapok

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

title: Linux Basics


text:
User:Ottwiz

Introduction
Hi. My name is Attila Kun from Hungary and I did back then in 2019 the Linux alapok (Linux Basics) document. Now it's available on Wikibooks. Have a pleasant reading!

Hobbies
Mainly Linux and everything that can be associated to 90s computing (Windows 95, 98)

I'm very active in the OpenStreetMap community.

My explanation of OSM

My OSM wikipage

title: User:Ottwiz


text:
Linux Basics/Types of Operating Systems

What is an operating system?
An Operating System (OS) is software that manages computer hardware and other software.

It's commonly portrayed as the bridge between hardware and software. For a more detailed definition see Operating system

What operating systems can be
Different operating systems look, function, and are used differently. For example:
 * The interface can be graphical (GUI) or command-line (CLI)
 * It could be used as a server, desktop, internet route, appliance, etc.
 * It could support just a single-user, or multiple-users (Also known as multi-user)
 * It could support running just a single task at a time, or multiple tasks (multi-tasking).

Let's look at these different options in more detail:
 * Command-Line (CLI): Text based user interface
 * Present in almost every OS
 * Allows for flexible command input and automation (executing scripts)
 * Fast
 * Fast Computationally - Excels on computationally constrained hardware or when every bit of performance is needed.
 * Many tasks are faster when performed through a CLI compared to a GUI.
 * Graphical User Interface (GUI): Icon, Widget, and Audio-based user interface
 * More Intuitive for many
 * Generally more approachable for new users, less instruction is required to train a user to use a well designed GUI.
 * Literacy is not necessarily required to use a GUI, an important consideration in some educational environments.
 * Some operations are faster than in a CLI without a prior script being made.
 * Automation is still possible, though often requires a third party program.
 * Almost always more computationally expensive then a CLI in terms of computer resources.
 * Single task: 1 task/ program can be run at a time
 * Multi task: Multiple programs can be run at a time
 * Preemptive: the OS can take resources
 * Cooperative: it only works if every resource is available
 * Single-user: Only one user can be handled at a time.
 * Some single user operating systems allow for different user profiles, but lack the ability to run programs from multiple accounts at once.
 * Multi-user: Multiple user accounts can be created and used simultaneously.
 * Multiple users can use the system simultaneously. This can be through a user locking their session to allow another user to log in on a traditional desktop while their applications continue to run in the background, or have two users literally logged in and operating at the same time in the case of a multiheaded system.
 * Filesystem must support the convention of user separation (so FAT16 and FAT32 are excluded, but EXT2,3,4; NTFS and modern FS's support it).
 * A long time ago this was not the case, so users could exploit others on the computer. Nowadays it's near impossible to get access to other users' directories.

DOS
MS-DOS, and Windows based on it (from 1.01 to ME):
 * CLI, with GUI as a bolt on add on with Windows
 * Vanilla MS-DOS is a pure CLI.
 * Early versions of Windows were simply graphical environments added on to MS-DOS, or later integrated with it. These versions included a program called MS-DOS Prompt to create CLI shells.
 * Single-user. Some versions allowed multiple user accounts, but were unable to allow them to be logged in simultaneously.
 * MS-DOS cost money back in the day, and is typically no longer sold in stores.
 * MS-DOS software is sometimes compatible with other DOS operating systems, some of which are still developed to this day.
 * Security issues, general obsolescence, and a lack of network focus make MS-DOS a terrible server or even networked operating system. MS-DOS can still work fine on offline machines.

Windows NT
Windows NT (Windows NT 3.x – 11):
 * GUI with de-emphasized CLI.
 * Most tasks in Windows are performed using the GUI.
 * CLI environments such as the basic Run and Command Prompt applications are typically included.
 * More recent versions of Windows offer the more advanced and capable Power Shell application.
 * Multi-user (here the user folders are encrypted, so you can't get access to others' folders without proper permission)
 * You typically have to pay for it, or be eligible for special promotions or offers.
 * There are server and desktop versions. There are further sub versions which target different market segments.

Unix and Compatibles
Linux:
 * CLI with optional GUI.
 * Some Distros are CLI only, especially those intended to be used on servers or embedded devices.
 * Most desktop distributions use a GUI by default with a de-emphasized CLI. Others try to strike a balance between the two.
 * Multi-user, so multiple user can be on the network, the folders can be encrypted, permissions can be set, widely customizable (both program- and interface-wise).
 * It's free as in freedom, and often free as in beer so you don't typically have to pay for it.
 * Most distributions are free.
 * For some enterprise distributions, such as Red Hat Enterprise Linux, you pay to get it directly from the company that makes it, and to get support.
 * There are server and desktop oriented distributions.

UNIX:
 * The BSD family includes a number of open source operating systems, as well as closed source operating systems.
 * There are a number of proprietary UNIX operating systems, such as Solaris (A direct UNIX descendent) and MacOS (Related to BSD).

Other: There are a few other UNIX-like operating systems you may read about while studying Linux
 * GNU Operating System - Many coreutils for Linux originated here.
 * MINIX - Important influence in the history of Linux, and still used in some applications.

title: Linux Basics/Types of Operating Systems


text:
Free Knowledge Culture Calendar/December 8

Today in 1943 the specialized first (partially) programmable electronic computer had its first test run before being installed at Bletchley Park for Britain’s cryptanalysis efforts against the Nazis. It was hardwired and programmed with switches.


text:
Linux Basics/Fundamental concepts in Linux

Distributions
By itself Linux is a Kernel - the core component of an operating system. However other components are required to make a full operating system. A Linux Distribution, or Distro for short, includes all the components needed to form a full operating system. Because there are a number of different component options to choose from, each Linux distro offers a unique spin on Linux, and are often specialized for handling certain tasks.

Command Line Interface

 * BASH
 * ZSH / Z Shell

Desktop Environments

 * KDE, Gnome, MATE, Xfce, Cinnamon, LXDE, LXQt, Pantheon, Budgie stb.

Desktop Managers

 * Desktop Managers: SDDM, GDM, LightDM

Package Manager
RPM: Red Hat, Fedora, CentOS, openSUSE stb.

DEB: Debian, Ubuntu, Linux Mint, MX Linux stb.

repository: container; programs and drivers can be found for the distros

package manager: it solves the dependency tree if there is an compatibility issue.

Red Hat Enterprise Linux

Red Hat Enterprise Linux (RHEL) is one of the most successful Linux distributions which is developed by Red Hat for commercial usage.

Official support for RHEL is available, and while support costs money, it is generally well regarded.

Package Manager: RPM - RHEL is the original home of RPM, and remains heavily associated with it.

Default User Interface: GNOME

Fedora
Fedora is a community distro associated with RHEL.

Unlike Red Hat Enterprise Linux, Fedora is gratis, costing no money.

Cutting edge features are often implemented in Fedora before they are added to RHEL.

Package Manager: DNF (RPM based), Flatpak

Default User Interface: GNOME (Wayland based)

Slackware

Slackware is the oldest Linux distribution under active development. The first version was released in 1993, based on the wide spread SLS Linux, and used floppy disks as an installation medium in the beginning.

Slackware pursues simple usability, stability and security as its main goals. It doesn't have automatic dependency handling. The aim since its release to become the most Unix-like Linux distribution.

Package Manager: slackpkg

Default User Interface: Bash

Debian

Debian is one of the oldest Linux distros. It was announced on August 13, 1993 by Ian Murdock. The word Debian comes from Debora (Ian's wife) and Ian's name.

Debian is not commercially oriented. In contrast to RHEL, the distro is driven by volunteers.

Debian is a solid and reliable operating system. Because of this, it serves as the foundation of many distributions like Ubuntu and Knoppix.

Package Manager: APT (dpkg)

Default User Interface: GNOME or XFCE

Ubuntu

Ubuntu is one of the most popular distributions, which has been developed by Canonical Ltd. since 2004.

The first release was 4.10 and since then, in every 6 month a newer version and in every 4th month of even year a Long-Term Support releases.

Package Manager APT, Snap

Default User Interface GNOME

Arch Linux

Arch Linux is an independent distribution for advanced Linux users.

It has rolling-release model, which means that it updates continuously instead of bigger releases.

Package Manager Pacman - Arch's own package manager

Default User Interface Bash

OpenSUSE

OpenSUSE is the sequel of SUSE Linux and it's a project which promotes of using Linux ensuring by this a free and complete distribution to the users.

Package Manager: ZYpp

User Interface: Selectable from major GUIs on install, including GNOME, KDE, and XFCE.

Gentoo

Gentoo Linux is a flexible, fast distribution using Portage package manager.

In contrast to other distributions, you have to compile the whole system from source, so the installation process may take hours depending on hardware.

Package Manager: Portage

Default User Interface: Bash

Tux the Penguin

The mascot of Linux is Tux, the penguin, which was planned by Alan Cox and Linus, and was drawn by Larry Ewing.

History
Why Linux? Linus Torvalds showed that MINIX isn't available for x86(it was only available for education purposes), so he programmed a kernel for x86.

In 1991 Linus Torvalds was sophomore student in University of Helsinki at the faculty of Computer Sciences. He was a self-educated hacker, and wanted to write his own operating system, so he decided to write one. Why? He wanted to explore the Intel 80386 CPU's protected mode, task-switching capabilities. That was around the summer of 1991.

GPL - The GNU General Public License is a widely used free software license, which was created by Richard Stallman for the GNU Project. The aim of GNU GPL is to grant the copying and distributing of free software ensuring the free use of the software for every user.

Linux is surrounded by shell s - command prompts, and X Window System can be built on it.

What are Linux distributions/distros? Operating systems that has Linux kernel under the hood. Under the list there are some examples. You can find all the others on Distrowatch.com with ratings for each one.


text:
Linux Basics/Installation, bootloader

Installing
There are a variety of ways to install Linux on a computer. Traditional installation methods for a desktop Linux environment can be either graphical or terminal based.

Installation media refers to the delivery method of the operating system. Common installation media includes USB storage devices or DVDs. Installation can also be done virtually, such as in the case of a network installation.

Linux distros can be installed directly on a computer as the sole operating system or installed alongside another operating system such as Windows or another installation of Linux.

Linux can even be run under a different operating system through the use of a virtual machine. By using software such as GNOME Boxes, Virtualbox, or VMware, a virtual machine can be created to install and run Linux on, while simultaneously running the original operating system, such as Windows, MacOS, or even another Linux distro. One can think of a virtual machine as a way to simply run Linux as one would run any other program, such as Firefox or LibreOffice.

Installers for Linux distributions come in a variety of forms. Below are two screenshots of installers, showing both a friendly graphical installer, and a powerful command line installer.

The Bootloader
Bootloaders are programs that help the computer start up and prepare an operating system. Sometimes known as system loaders, one can compare bootloaders to the starter of a car or an usher at a theater showing you to your seat.

One of the most common bootloaders used on desktop Linux is GRUB. With GRUB you can give boot parameters to determine which operating system should boot up. GRUB also has additional features, including a memory test and hardware test, which checks if the computer hardware has any errors.

Bootloader can be installed on HDD in case of MBR, e.g. /dev/sda (first HDD), in case of GPT you can give which partition would be the "BIOS boot" one (e.g. /dev/sda3 - first hard disk's third partition), so the bootloader will be installed to the location which we picked.

title: Linux Basics/Installation, bootloader


text:
Planet Earth/4e. Blaise Pascal and his Barometer

In 1647, Blaise Pascal living in Paris, France, was a celebrated genius in mathematics and inventor of the first mechanical calculator, when he took an interest in a great scientific debate. Some scientists argued that a complete vacuum was impossible. These scientists implied that it was impossible to remove all evidence of substances, including gas from a sealed glass container. There would be some substance left inside, no matter how hard you sucked out the gas from the glass container. Blaise Pascal argued that this idea was wrong. A vacuum was possible, and so he wrote a small pamphlet on the subject entitled Expériences nouvelles touchant le vide, or New Experiments with the Vacuum. Throughout the book Pascal described experiments with pipes, syringes, bellows and siphons, with a variety of liquids, including quicksilver (mercury). Pascal developed the modern scientific idea of physical forces exerting against substances, called pressure, which today is measured in the units of pascal. One pascal is equivalent to one newton of force applied over an area of one square meter. One particular experiment excited Blaise Pascal more than any other: A series of experiments had been conducted in Italy in the 1630s and 1640s that showed how water would stay inside a sealed glass tube, even when it was opened from the bottom and allowed to drain into a basin. This failure to drain all the water into the basin suggested that some pressure was holding the water up inside the tube. Evangelista Torricelli, a student of Galileo, suggested that air had weight, and was pushing down against the liquid in the basin, which prevented the water from flowing out of the glass tube. Torricelli began experimenting with a new device filled with mercury, rather than water. Mercury worked better, because experiments with water required very long tubes (over 10 meters) and big water basins to work. Mercury worked well since the length of the tube could be short, enough to move the device around. Torricelli’s new device was the first mercury barometer. A barometer measures the amount of pressure, or weight that air pushes down from the atmosphere. Torricelli viewed the atmosphere like an ocean of water above our heads, which would have weight, and this thick atmosphere of gasses would push down against the surface. The more pressure or weight the atmosphere had, the higher the mercury would be in the glass tube. Blaise Pascal wondered if Torricelli was right, and quickly came to an idea to test it. If you climbed a gigantic mountain, the amount of atmosphere above you would be less, and hence the pressure exerted would be less as well, and the mercury in a barometer would be lower than observed at the base of the mountain. Pascal was not a mountaineer nor much of an adventurer. He did have two sisters, one of which was married to a handsome man named Florin Périer. Over the summer Pascal convinced his brother-in-law to hike to the top of the volcano, Puy de Dôme, and along the way measure the height of the mercury in the tube of a barometer. Périer agreed and in September he made the hike to the summit, recording the level of the mercury along the way. At the same time, near the base of the mountain, the level of the mercury in a second barometer was measured. It was found that as Périer hiked higher and higher up the volcano. The lower the mercury level was compared to the barometer at the base of the mountain. Pascal was delighted at the results of the experiment and proved that Torricelli was right; the atmosphere had weight that presses down on the surface of the Earth. Barometers quickly became a new scientific tool to measure atmospheric pressure (as well as the height of mountains). Atmospheric pressure decreases with increasing elevation. The higher the altitude you are, the lower the atmospheric pressure. Gasses have weight, and press down on the surface of the Earth, due to the atmosphere’s mass and the Earth’s gravitational force. Near the surface of Earth at sea level, the pressure exerted by the atmosphere is 101,325 Pascals, which is equivalent 1013.25 millibars, or 101.325 kilopascals, or equivalent to mercury measured up to 760 mm in height (often expressed as 760 mm Hg).

What happens to a helium filled balloon as it rises in the atmosphere? If there is less pressure exerted on it as it rises upward, what happens to the balloon? With less pressure, the balloon will expand the higher up it floats into the atmosphere, as the gasses inside the balloon will fill more volume, as less pressure is pushing against the outside of the balloon. Eventually the balloon will pop or break, as it is stretched larger. You may experience discomfort when you drive quickly over a mountain pass, or are in an airplane due to this change in pressure. Inside your ears, the middle ear cavity (which holds the incus, malleus and stapes bones) is an air-filled cavity. As atmospheric pressure decreases, this middle ear cavity can expand, by pushing against your ear drum, causing discomfort. A small opening, controlled by a muscle can open this air-filled cavity to relieve this building internal pressure, but this opening can be blocked by mucus if you have a head cold or sinus infection, this condition could result in a ruptured ear-drum.

The gas molecules that compose Earth’s atmosphere are compressed by the atmospheric pressure, such that the density of gas molecules increases the closer you get to the surface of the Earth, and the closer you are to sea level. Gasses are highly compressible by the weight of the atmosphere above, and results in the highest concentration of gas molecules near the surface of the Earth. In fact, half of all gas molecules in the atmosphere reside below an altitude of 5.5 kilometers, or 18,045 feet. This means that there are nearly half as many molecules of oxygen available per volume on top of an 18,000-feet mountain, as there is near sea level. This is why mountaineers climbing high mountains, such as Everest (29,000 feet high), will take oxygen tanks with them. What causes altitude sickness is the thin mountain air that results from less atmospheric pressure and less available oxygen molecules per volume. Hiking a high mountain requires more breaths for the body to receive the same amount of oxygen compared to a hike at sea level. Measuring atmospheric pressures using a barometer is an important tool in weather forecasting. Atmospheric pressure can vary from place to place on the surface of the Earth, and over time. Isobar maps are daily to hourly maps composed of contour lines of equal atmospheric pressures, showing geographic regions of high pressure and low pressure, as the distribution of the atmosphere can change over time. The highest recorded pressure on the surface of the Earth was 108.48 kilopascals (in Mongolia) with the lowest recorded value of 87.00 kilopascals (during a 1979 typhoon in the Pacific), compared to the standard sea level atmospheric pressure of 101.325 kilopascals. Atmospheric pressures vary across the surface of the Earth and are important in weather forecasting.


text:
Free Knowledge Culture Calendar/April 28

Today is Ian Murdock’s birthday.


text:
Planet Earth/4f. Why are Mountain Tops Cold?

Mountain Tops are Cold
It would seem that the tops of high mountain peaks would be warmer, given that the sun is closer to the tops of mountains. So why are the tops of mountains on Earth colder than lower elevations? This strange relationship between elevation and temperature is a fascinating aspect of Earth’s atmosphere. The temperature profile of the atmosphere changes with altitude because of the absorption of atmospheric gasses that occupy different layers of Earth’s atmosphere, and the absorption of sunlight on the Earth’s surface.

Imagine an experiment with a lamp, representing the sun, shining on a surface below it representing the Earth. If the surface was a perfect reflector of the light (albedo = 1), such as a mirror, then the closer you move toward the light bulb in the lamp, the warmer it would be. The coldest place would be next to the mirror, the furthest distance from the lamp. Now imagine that the surface is rather a grayish color (albedo = 0.12), with only 12% of the light reflected back into space. In this case, the surface will absorb the energy from the light, and the surface will warm over time. So that the coldest point between the lamp and the surface would no longer be the surface, but be somewhere above the surface. This cold point or inflection point is known as a pause. A hill on this gray surface will cool with elevation as you approach this colder layer (or pause) above the surface. The moon is an example of this simple style of a planetary body that lacks an atmosphere, it has a low albedo of 0.12. The surface of the moon oscillates between extremely cold and hot temperatures, with nighttime temperatures dropping below −150 degrees Celsius, below the freezing point of dry ice, and daytime temperatures well above 106 degrees Celsius, higher than the boiling point of water. This great oscillation and range of daily temperatures is a result of the lack of any absorption of sun light by gasses above the surface of the moon. When the sun is shining on the surface of the moon temperatures soar, and when the moon turns from the sun, temperatures plunge in the dark. Earth would have a similar great oscillation of temperatures if not for its atmosphere.

Oxygen plays an important role in Earth’s atmospheric temperatures. Oxygen, Nitrogen and Argon, are the most abundant gasses on Earth. Oxygen blocks ultraviolet (high energy) light from the sun. Like a second surface above the ground, these gasses are heated by the sun’s high energy ultraviolet rays, near the top of the stratosphere (50 km above the Earth). Ozone blocks more of the incoming ultraviolet sun light resulting in a warmer layer. This warm layer above the surface of the Earth is known as the Stratopause, and marks the top of the Stratosphere. The air is denser below the Stratopause. Temperatures are cooler above and below this layer, resulting in two cold layers below and above this heated zone high in Earth’s atmosphere. If the atmosphere lacked oxygen, or other gasses that absorb high energy ultraviolet rays, the temperature profile would lack these two distinct cold layers, and have only a one cold layer. The presence of oxygen and ozone in the atmosphere results in temperatures increasing below the Stratopause, within the high Stratosphere of the atmosphere. Note that the temperatures in the Stratopause are still pretty cold compared to Earth’s surface, reaching around −15 degrees Celsius, but this is much higher than the two very cold layers in the atmosphere. The Tropopause, which is about 15 kilometers above the Earth’s surface, dips to −51 degrees Celsius, while the Mesopause, above the Stratosphere at 80 kilometers is even colder −100 degrees Celsius. These three layers, the two cold layers, the Mesopause and Tropopause, and single warmer layer, Stratopause, divide the atmosphere into four layers; the lowest layer is the Troposphere, then Stratosphere, Mesosphere, and highest Thermosphere, with the highest temperatures, but lowest pressures of Earth’s atmosphere.

Troposphere
As the nearest layer of the atmosphere, and the layer we breathe and live our lives within, the troposphere is the layer that contains most of Earth’s weather. The term tropos, means change, and this lowest zone of the atmosphere experiences much change due to weather. It is also one of the warmest layers of atmosphere because of its proximity to the surface of the Earth. The troposphere is between 8 and 14 kilometers thick depending on where you are on Earth. Bulging near the equator and is thinner near the poles. As the air that we breathe, the air is densest within this layer in the atmosphere, especially near sea level. Composed of 78% nitrogen, 21% oxygen and 1% argon, the air in the troposphere also contains water vapor, carbon dioxide, methane and other Green House gasses. These heavier gas molecules are more abundant closer to the surface of the Earth. Because these gasses absorb infrared light, they work to retain much of the heat emitted by the Earth’s surface. Clouds, and water vapor is highest within the troposphere, and clouds rarely form above 15 kilometers above the Earth’s surface. Temperatures in the troposphere decrease with elevation from averages at the surface of 15 degrees Celsius decreasing to −51 degrees Celsius near the top. This decrease results in mountain peaks being considerably colder than valleys. Air within the troposphere is the only air that animals can breathe, including humans.

Stratosphere
If you have traveled by airplane, most commercial aircraft maintain a cruising altitude near the base of the Stratosphere, about 33,000 feet to 42,000 feet above the ground, or 10 kilometers to 13 kilometers, just above the cloud covered world below. Temperatures at this altitude are chilly, with average temperatures dipping nearly to −60 degrees Celsius. Air pressure drops dramatically in the Stratosphere, from 226 mm Hg (30 kilopascals) to 1 mm Hg (0.146 kilopascals) at the top of the Stratosphere. Air pressure is so low that most gas molecules in the Stratosphere are so widely spaced that the air is unbreathable for humans and even birds. Clouds do not form within the Stratosphere, because of these low pressures, as most water vapor is confined to the Troposphere below. Temperatures however increase with altitude within the Stratosphere, because it is an important layer for Ozone formation from oxygen. Oxygen, Nitrogen and Argon gas make it up to these high altitudes above Earth, and the top of the Stratosphere marks the important absorption point of ultraviolet light from the sun. Temperatures are warmed at the very top of the Stratosphere because of the absorption of these high energy wavelengths of light from the sun.

Mesosphere
The mesosphere is 35 kilometers thick, about 22 miles, with air pressure dropping to a minuscule 0.17 mm Hg (or 0.02 kilopascals) of pressure, with even lower pressures near the top of the Mesosphere. Few gas molecules are found this high in the atmosphere. Light molecules of Helium (He) and Hydrogen (H2) gas becomes more abundant in the Mesosphere, but also atoms start to ionize at these very low pressures. Oxygen, typically bonded in pairs, become isolated as ions of O−2, as does Nitrogen N−3. Temperatures drop with altitude in the Mesosphere, becoming extremely cold near the top. Because there is so little gas in the Mesosphere to scatter light, the sky looks much darker, almost as dark as outer space. “Meso” means middle, and there is still another thick layer of atmosphere even higher above Earth.

Thermosphere
The thermosphere is what we normally think of as outer space. The air density in the thermosphere is so low that it resembles the darkness of outer space. Most scientists place the boundary with space about 100 kilometers above the Earth, which is within the thermosphere. The thermosphere is the thickest layer examined so far, with a thickness of 90 kilometers (56 miles). The air pressures are so low, that this layer is near a vacuum, similar to outer space, but it does contain many charged ions of gasses. Temperatures rise within the Thermosphere because these ions interact with the incoming high energy ultraviolet and gamma rays from the sun. During the day, sunlight warms the upper Thermosphere up to 2,000 degrees Celsius, and during the night temperatures drop to 500 degrees Celsius near the top of the Thermosphere. The top of the Thermosphere is heated because of the interaction of these charged ions at the edge of Earth’s atmosphere. The Thermosphere is also a very dangerous place. With such high temperatures, space craft can easily be burned and damaged. For example, the space shuttle Columbia upon re-entry into the thermosphere these high temperature atmospheric gasses were able to penetrate the heat shield and destroyed the internal wing structure, and the shuttle broke apart, killing its seven crew members on February 1, 2003.

Gasses high in the thermosphere become ionized by x-ray, gamma and ultraviolet light from the sun, which results in electrons leaving atoms. These highly charged particles circulate in near vacuum like pressures in the thermosphere. These charged particles (isolated electrons, protons, and neutrons) collide and are excited into higher energy states, releasing photons. This emission of photons of light can be observed as colorful auroral displays from the surface of the Earth. Given the electromagnetic attractions of these charged particles, they tend to collect near the magnetic poles of the Earth, high above the magnetic north pole and magnetic south pole. On some dark nights enough of these charged particles will be excited emitting photons, which can be observed from Earth’s surface as spectacular displays of greenish light in the night sky. The Aurora borealis or Northern Light, and the Aurora australis or Southern Light, can be observed from high latitudes on the surface of the Earth, especially on cloudless nights following high solar activity.

Some atmospheric scientists refer to the Thermosphere, as the Ionosphere, because it is the region in the atmosphere where ionized particles are found. The Thermosphere/Ionosphere is important to study, since the ionized particles common in this layer can affect long range radio transmissions. Observations of the changes in the ionized particles within the Thermosphere is often referred by the media, as Space Weather.

Exosphere
The Exosphere is the term used to define the outermost layer where the density is so low that gas molecules and ions do not interact with each other, and the pressure is a near vacuum, similar to space. The Exosphere likely is composed of mostly Helium and Hydrogen, although little is known of this region. It begins about 600 kilometers (374 miles) from Earth’s surface. Low Earth Orbiting space satellites span across the Thermosphere and Exosphere boundary, with altitudes from 180 to 2,000 kilometers above Earth. The International Space Station, with a low orbiting height of 409 kilometers above the Earth, actually orbits the Earth from a position high in the Thermosphere. Most GPS satellites orbit higher within Medium Earth Orbiting space, about 20,200 kilometers (12,552 miles) above the Earth. Geosynchronous orbiting satellites orbit the Earth by matching the Earth’s spin, such that from Earth’s surface, a satellite in geosynchronous orbit returns to exactly the same position in the sky after a period of one sidereal day. Geosynchronous satellites are important for global radio and cellular telephone communications, first proposed by science fiction author Arthur C. Clarke, who proposed the idea of high-altitude satellites in the 1940s. The first phone call using geosynchronous satellites was made on August 23, 1963 between U.S. President John Kennedy and Nigerian prime minister Abubakar Tafawa Balewa, both men would later be assassinated while in office. Most Geosynchronous orbits have an altitude around 35,786 kilometers (22,236 miles) from the Earth’s surface.

A very special type of geosynchronous orbit is the geostationary orbit, in which satellites match the rotation of the Earth. Communications satellites are often placed in a geostationary orbit so cell towers do not have to rotate to track these satellites, but can be pointed permanently at the position in the sky where the satellites are located in sync with the Earth’s rotation. The farthest observing space satellites are located much further into space, in the High Earth Orbit, which extends above 35,786 kilometers, all the way toward the distance to the moon, 384,000 kilometers away. High Earth Orbits are infrequently used because of the costs involved, but have been used to monitor nuclear bomb testing by hostile nations. The United States Vela satellite network, launched in 1963, successfully identified nuclear testing in the Indian Ocean by the Israeli military in 1979. Satellites at these high orbits can be affected by the gravity of the moon, and are only used in missions requiring very long distances above Earth. Such as the IBEX High Earth Orbiting satellite which maps particles that trail behind the motion of the solar system as it travels through interstellar space.


text:
Free Knowledge Culture Calendar/January 10

Today in 2001, Nupedia starts a wiki which went on to become Wikipedia, the biggest encyclopedia of all times.


text:
Linux Basics/If you want to deal more with Linux

If you would like to to watch some Linux content on YouTube, I'd recommend DistroTube,Switched to Linux and ExplainingComputers. The last one it's not Linux oriented, but has some Linux content, I prefer Chris' channel.

It is also recommended to join some Telegram groups to get some help if you're stuck (most Linux distros have at least a few English language groups. Some local ones like there is an Ubuntu Hour community in Hungary which has its Telegram group), many Linuxers use this platform, although some like ArcoLinux's developer(Erik Dubois) use Discord as well.

In Hungary, members from FSF use a matrix server (matrix.grin.hu), to communicate with each other, and there is the PenguinPit Discord server for those who use Discord a lot.

This article from itsfoss.com contains 25 free Linux books to learn more. I also prefer The Linux Command Line which contains lots of knowledge in 555 pages. However, on Wikibooks, there are some Linux books here too. Check them out, maybe those get your attention.


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1938 03

Link to Issue PDF
| WorldRadioHistory.com's scan of | Australasian Radio World - Vol. 02 No. 11 - March 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 03

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

March 1, 1938; Vol. 2 - No. 11; Price, 1/-

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

Cover Photo: Photo of Ever Ready Factory at Rosebery (see story on page 8)

Highlighted Contents: Two-Band Portable Transmitter-Receiver: Triple-Range Vacuum Tube Voltmeter: Two-Valve A.C. Superhet: More about the "1938 Fidelity D.W. Six": 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. - MARCH 1, 1938 - No. 11.

P.02 - Contents
CONTENTS:

Two-Band Portable Transmitter-Receiver. . . . 3

Battery-Operated Portable Transmitter. . . . 10

Radio Ramblings. . . . 12

Japanese B.C. Stations. . . . 15

Sydney Dxer Logs Europe on B.C. Band. . . . 16

Assembling And Wiring the Fidelity Dual-Wave Six. . . . 18

Two-Valve A.C. Shortwaver Uses Coil-Switching. . . . 20

Radio Valves In The Making (3). . . . 24

A Triple-Range Valve Voltmeter. . . . 27

What’s New In Radio. . . . 30

Radio Step By Step (15). . . . 32

Two-Valve Local Station Superhet. . . . . 35

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

Shortwave Review. . . . 38

Round The Shacks (7). . . . 40

1938 Radio Handbook Now Available. . . . 43

Police Signals Heard 10,000 Miles. . . . 46

DX News And Views. . . . 47

Shortwave Station Addresses. . . . 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)


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1938 04

Link to Issue PDF
| WorldRadioHistory.com's scan of | Australasian Radio World - Vol. 02 No. 12 - April 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 04

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

April 1, 1938; Vol. 2 - No. 12; Price, 1/-

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

Cover Photo: Photo of 200 k.w. transmitter at Rugby, England (see story on page 8)

Highlighted Contents: "Comet Dual-Wave Four": Radiokes "1938 Moneysaver": Portable 5-Metre Transceiver: Midget 3-Watt Amplifier: New Crown Push-Button Kit: Eliminating Man-Made Interference

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. - APRIL 1, 1938 - No. 12.

P.02 - Contents
CONTENTS:

Comet Superhet Four. . . . 3

Crown Releases Push-Button Kit For Set-Builders. . . . 6

Portable Five-Metre Transceiver. . . . 9

Radiokes 1938 D.W. Moneysaver Superhet. . . . 14

Pre-Selector Unit Sharpens Tuning, Increases Gain. . . . 16

50-Watt Transmitter For New Power Limit. . . . 18

Infinite Baffle Aids Tonal Fidelity. . . . 20

Shortwave Aerials For DX Reception (1). . . . 23

"Eaglet" Gives Outstanding Performance. . . . 26

Building A Midget Three-Watt Amplifier. . . . 27

DX Contest Winner Has Logged Over 100 Countries. . . . 30

Tracking Down Power Interference (1). . . . 31

What's New In Radio. . . . 33

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

Sun-spot Activity Now Approaching Maximum. . . . 38

Shortwave Review. . . . 39

Hourly Tuning Guide. . . . 42

Fourth "Radio World" S.W. DX Contest. . . . 46

Round The Shacks (8). . . . 46

DX News And Views. . . . 47

VK Amateur Transmitters — Additions And Amendments. . . . 47

Index Of Technical Features, "Radio World," Vol. 2. . . . 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 15th 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)


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1938 05

Link to Issue PDF
| WorldRadioHistory.com's scan of | Australasian Radio World - Vol. 03 No. 1 - May 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 05

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

May 2, 1938; Vol. 3 - No. 1; Price, 1/-

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

Cover Photo: Photo of A.W.A. Teleradio 3A (see story on page 8)

Highlighted Contents: Special Battery Set Number: "Air-Cell Dual-Wave Four": "Scout Battery Three: "Comet Dual-Wave Four": Eliminating Power Interference: A.O.C.P. Questions and Model Answers.

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. 3. - MAY, 1938 - No. 1.

P.02 - Contents
CONTENTS:

The Air-cell Dual-wave Four. . . . 3

Radiokes Release New Range of Power Transformers. . . . 7

Radio Ramblings. . . . 8

The Comet Superhet Four. . . . 10

An Appreciation From A.T.R.S.I. .. . . 12

"Pirate" Uses Lakemba Club Call. . . . 14

The Triode And Its Applications. . . . 16

The Scout Battery Three. . . . 18

A Trip Through The Ever Ready Factory. . . . 22

Shortwave Aerials For DX Reception (2). . . . 27

Tracking Down Power Interference (2). . . . 30

What's New In Radio. . . . 34

A.O.C.P. Questions And Answers. . . . 39

All-Wave All-World DX News. . . . 41

Shortwave Review. . . . 42

DX Notes And News. . . . 45

Hourly Tuning Guide. . . . 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 15th 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)


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1938 06

Link to Issue PDF
| WorldRadioHistory.com's scan of | Australasian Radio World - Vol. 03 No. 2 - June 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 06

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

June 1, 1938; Vol. 3 - No. 2; Price, 1/-

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

Cover Photo: Photo of B.B.C.'s mobile television unit at Surrey Cricket Club (see story on page 8)

Highlighted Contents: Push-Button Dual-Wave Superhet uses Permeability Tuning Throughout - With Beam Tetrode Output: Latest List of World Short-Wave Stations: More about the "Air-Cell Dual-Wave Four".

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. 3. - JUNE, 1938 - No. 2.

P.02 - Contents
CONTENTS:

The "Auto-Tune Dual-Wave Five". . . . 3

Calstan Test Oscillator. . . . 5

Radio Ramblings. . . . 6

Radiokes Release Eight-Station Teletuner. . . . 10

More About The Air-Cell D.W. Four. . . . 11

Lakemba Club Holds Eighth Annual Reunion. . . . 14

32-Watt Amplifier Uses 6L6G's In Pushpull. . . . 18

A.O.C.P. Questions And Answers. . . . 20

World Shortwave Stations. . . . 22

Tracking Down Power Interference (3). . . . 28

Round The Shacks (8). . . . 32

What's New In Radio. . . . 33

All-Wave All-World DX News. . . . 39

Shortwave Review. . . . 40

Hourly Tuning Guide. . . . 43

American Radio Police Calls. . . . 44

Fourth S.W. DX Contest. . . . 45

DX News And Views. . . . 46

Ex-Fingerprint Expert Conducts PCJ Session. . . . 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 15th 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)


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1938 07

Link to Issue PDF
| WorldRadioHistory.com's scan of | Australasian Radio World - Vol. 03 No. 3 - July 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 07

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

July 1, 1938; Vol. 3 - No. 3; Price, 1/-

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

Cover Photo: Photo of Enjoying a cricket broadcast with an S.T.C. Model "Q" Triple-Wave Console. (See page 10.)

Highlighted Contents: "Auto-Tune Dual-Wave Five": Home Recording for the Amateur: Four-Watt Beam Amplifier: Amateur Station Equipment - Monitor & Modulation Meter: 3-Unit Power Pack: Latest S.W. 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. 3. - JULY, 1938 - No. 3.

P.02 - Contents
CONTENTS:

The "Auto-Tune Dual-Wave Five". . . . 3

Model "Q" Console Is Latest S.T.C. Release. . . . 10

Four-Watt Beam Amplifier. . . . 11

Home Recording For The Amateur. . . . 14

Amateur Station Equipment (1) — Monitor And Modulation Meter. . . . 18

World Shortwave Stations. . . . 23

A.O.C.P. Questions And Answers. . . . 27

Pentode And Beam Tetrode Valves. . . . 29

200 Visitors Inspect Philips Valve Works. . . . 31

What's New In Radio. . . . 32

Palec "VCT" Valve And Circuit Tester. . . . 35

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

Shortwave Review. . . . 38

Hourly Tuning Guide. . . . 41

Official Australian Radio Service Manual. . . . 45

DX News And Views. . . . 46

"1938 De Luxe Fidelity Eight". . . . 47

International Amateur Prefixes. . . . 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)


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1938 08

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

P.02 - Contents Banner
The Australasian Radio World

Incorporating the

All-Wave All-World DX News

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

Vol. 3. - January, 1939 - No. 9

P.01 - Contents Banner
From 1940 03

The Australasian Radio World

Incorporating the

All-Wave All-World DX News

Vol. 4. - MARCH, 1940 - No. 10.

P.02 - Contents
CONTENTS:

P.02 - Publication Notes
1936 08

The "Australasian Radio World" is published monthly by A. E. Read. 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 15th 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.

1937 02

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 15th 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.XX)

Only 1939 04

The "Australasian Radio World" is published monthly for the proprietors, 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)

From 1939 05

The "Australasian Radio World" is published monthly by Read Publications. 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.

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.XX)

1939 12

The "Australasian Radio World" is published monthly by Read Publications. 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.

Note: Address of Editorial offices after December 10, 1939, will be 117 Reservoir Street, Sydney.

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.40)

From 1940 01

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 Pty. Ltd., 117 Reservoir Street, Sydney, N.S.W., for the proprietors of the "Australasian Radio World," 117 Reservoir St., Sydney (Footnote P.XX)

From 1940 03

The "Australasian Radio World" is published monthly by A. G. Hull. 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 Pty. Ltd., 117 Reservoir Street, Sydney, N.S.W., for the proprietors of the "Australasian Radio World," 117 Reservoir St., Sydney (Footnote P.XX)

From 1940 10

The "Australasian Radio World" is published monthly by A. G. Hull. Editorial offices, 117 Reservoir Street, Sydney, N.S.W. Telephone MA2455.

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

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.XX)


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1938 09

Link to Issue PDF
| WorldRadioHistory.com's scan of | Australasian Radio World - Vol. 03 No. 5 - September 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 09

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

September 10, 1938; Vol. 3 - No. 5; Price, 1/-

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

Cover Photo: Photo of New Conveyor Belts at new Radiokes Factory, Chippendale, Sydney (See Page 8.)

Highlighted Contents: "Triplex All-Waver": More about the "1938 De Luxe Fidelity Eight": "Air-Ace Communications Four": "Vibra D.W. Five": "Trans Tasman U.H.F. Two": Winning Entry in QSL Card Contest

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. 3. - SEPTEMBER, 1938 - No. 5.

P.02 - Contents
CONTENTS:

"Atlas All-Waver". . . . 3

Brimar Releases New 6AG6-G Output Pentode. . . . 8

Rectifiers, Filters, And Hum. . . . 10

Radio Ramblings. . . . 12

The "Challenger Dual-Wave Six". . . . 16

The "Ultra-Shorts" In Review. . . . 17

A.O.C.P. Questions And Answers. . . . 21

High Fidelity Reception Of Local Stations. . . . 24

Radio Reminiscences. . . . 27

The "1938 De Luxe Fidelity Eight". . . . 28

The "Trans-Tasman U.H.F. Two". . . . 30

What's New In Radio. . . . 32

Lectures On Oscillograph And Home Recording. . . . 35

"Empire" Power-Pack Wiring Plan. . . . 37

Philips Photo Cell Has Many Applications. . . . 38

Assembling And Wiring The "Air-Ace Communications Four". . . . 39

"Vibra Dual- Wave Five". . . . 44

Shortwave Review. . . . 45

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)


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Biographies/Alfred Earl Read

Alfred Earl Read was a prominent radio journalist and magazine manager in New Zealand and Australia during the 1930s and 1940s. In the early 1930s he was the editor of the New Zealand Radio Times. In 1936 he relocated to Australia and established the Australasian Radio World in a partnership with his brother-in-law. The magazine was sold in 1940 to Allan Galbraith Hull, brother of the well known Ross Amos Hull, however Earl continued with the magazine as business manager for a number of years. The All-Wave All-World DX Club was the brainchild of Read and was incorporated within Australasian Radio World from its inception. For a small once-off payment, the club provided its members with a distinctive membership number, a club badge and access to official stationery. Total membership approached one thousand and its members were a core readership of the magazine. After the sale of the magazine in 1940, operation of the club was continued by A. G. Hull, but eventually petered out during WW2. After the war, a revival of the club was considered, but there was insufficient interest and it lay dormant until the magazine's demise in 1951. A summary biography has not yet been prepared however the following resources have been assembled in preparation:

 * Transcriptions and Notes - Alfred Earl "Earl" Read - More than 50 transcriptions and notes

 * Photos, QSL cards and other graphics - Alfred Earl "Earl" Read - Nothing uploaded as yet


text:
A-level Mathematics/CIE/Pure Mathematics 2/Differentiation

Differentiating Logarithmic and Exponential functions
The function $$y = e^x$$ is its own derivative: $$\dfrac{d}{dx} e^x = e^x$$. The constant $$e$$ is defined such that this is true.

An exponential function with a different base can be converted into a function of the form $$e^{kx}$$ using logarithms, e.g. $$2^x = e^{\ln 2 x}$$. The derivative of such an expression can be found using the chain rule: $$\dfrac{d}{dx} 2^x = \dfrac{d}{dx} e^{\ln 2 x} = \ln 2\ e^{\ln 2 x} = 2^x \ln 2$$.

$$\dfrac{d}{dx} e^{f(x)} = f'(x)e^{f(x)}$$

The derivative of a logarithm is $$\dfrac{d}{dx} \ln x = \frac{1}{x}$$. Applying the chain rule to this produces the result:

$$\dfrac{d}{dx} \ln(f(x)) = \frac{f'(x)}{f(x)}$$

It is important to know how these rules interact with other expressions.

e.g. $$\dfrac{d}{dx} e^{x^2 + \ln \tfrac{1}{x}} = e^{x^2 + \ln \tfrac{1}{x}} (\dfrac{d}{dx} x^2 + \ln \tfrac{1}{x}) = e^{x^2 + \ln \tfrac{1}{x}} (2x + \frac{-x^{-2}}{1/x}) = e^{x^2 + \ln \tfrac{1}{x}} (2x - x^{-1}) $$

Differentiating Trigonometric Functions
The trigonometric functions have the following derivatives:

 * $$\dfrac{d}{dx} \sin x = \cos x $$
 * $$\dfrac{d}{dx} \cos x = -\sin x $$
 * $$\dfrac{d}{dx} \tan x = \sec^2 x $$
 * $$\dfrac{d}{dx} \tan^{-1} x = \frac{1}{1+x^2}$$

The Product Rule
The product rule states that:

$$\dfrac{d}{dx} f(x)g(x) = f(x)g'(x) + g(x)f'(x)$$

e.g. $$\dfrac{d}{dx} xe^x = x\dfrac{d}{dx}e^x + e^x\dfrac{d}{dx}x = xe^x + e^x = e^x(x + 1)$$

The Quotient Rule
The quotient rule is a special case of the product rule when one of the terms in the product is a reciprocal.

e.g. Evaluate $$\dfrac{d}{dx} \frac{2x+3}{x+4} $$

$$\begin{align} \dfrac{d}{dx} \frac{2x+3}{x+4} &= \dfrac{d}{dx} (2x+3)\frac{1}{x+4}\\ &= (2x+3)\dfrac{d}{dx}\left(\frac{1}{x+4}\right) + \frac{1}{x+4}\dfrac{d}{dx}(2x+3) \\ &= -(2x+3)(x+4)^{-2} + \frac{1}{x+4}(2) \\ &= \frac{-(2x+3)}{(x+4)^2} + \frac{2}{x+4} \\ &= \frac{-(2x+3)}{(x+4)^2} + \frac{2x + 8}{(x+4)^2} \\ &= \frac{2x + 8 - 2x - 3}{(x+4)^2} \\ &= \frac{5}{(x+4)^2} \end{align}$$

In general:

$$\begin{align} \dfrac{d}{dx} \frac{u}{v} &= u\dfrac{d}{dx}\frac{1}{v} + \frac{1}{v}\dfrac{du}{dx} \\ &= u(-v)^{-2}\dfrac{dv}{dx} + \frac{v}{v^2}\dfrac{du}{dx} \\ &= \frac{-u\tfrac{dv}{dx} + v\tfrac{du}{dx}}{v^2} \\ &= \frac{v\tfrac{du}{dx} - u\tfrac{dv}{dx}}{v^2} \end{align}$$

Implicit Differentiation
Implicit differentiation is where we differentiate a function which is not defined explicitly, with y as the subject. To do this, it is sensible to use the chain rule.

e.g. Find an expression for $$\dfrac{dy}{dx}$$ when $$x^2 + y^2 = 1$$.

$$\begin{align} x^2 + y^2 &= 1 \\ \dfrac{d}{dx} x^2 + y^2 &= \dfrac{d}{dx} 1 \\ 2x + \dfrac{dy^2}{dx} &= 0 \\ 2x + \dfrac{dy^2}{dy}\dfrac{dy}{dx} &= 0 \quad\text{Use the chain rule} \\ 2x + 2y\dfrac{dy}{dx} &= 0 \\ 2y\dfrac{dy}{dx} &= -2x \\ \dfrac{dy}{dx} &= -\frac{2x}{2y} = -\frac{x}{y} \end{align}$$

Sometimes, we need to use the product rule too.

e.g. Find an expression for $$\dfrac{dy}{dx}$$ when $$x^2 + 6xy + y^2 = 1$$.

$$\begin{align} x^2 + 6xy + y^2 &= 1 \\ \dfrac{d}{dx} x^2 + 6xy + y^2 &= \dfrac{d}{dx} 1 \\ 2x + \dfrac{d}{dx}6xy + \dfrac{d}{dx}y^2 &= 0 \\ 2x + 6x\dfrac{dy}{dx} + y\dfrac{d}{dx}6x + \dfrac{dy^2}{dy}\dfrac{dy}{dx} &= 0 \\ 2x + 6x\dfrac{dy}{dx} + 6y + 2y\dfrac{dy}{dx} &= 0 \\ 2x + 6y + (6x + 2y)\dfrac{dy}{dx} &= 0 \\ (6x + 2y)\dfrac{dy}{dx} &= - 2x - 6y \\ \dfrac{dy}{dx} &= \frac{-2x-6y}{6x+2y} \\ \dfrac{dy}{dx} &= \frac{-x-3y}{3x+y} \end{align}$$

Parametric Differentiation
A parametric function is where instead of $$y$$ being defined by $$x$$, $$y$$ and $$x$$ are both linked to a third parameter, $$t$$. e.g. $$x = 3t, y = t^2$$

To find $$\dfrac{dy}{dx}$$ when $$y$$ and $$x$$ are defined parametrically, we need to use the chain rule:

$$\dfrac{dy}{dx} = \dfrac{dy}{dt}\times\dfrac{dt}{dx} = \dfrac{dy}{dt}\div\dfrac{dx}{dt}$$

So for the example $$x = 3t, y = t^2$$, $$\dfrac{dx}{dt} = 3$$ and $$\dfrac{dy}{dt} = 2t$$, thus $$\dfrac{dy}{dx} = \dfrac{dy}{dt}\div\dfrac{dx}{dt} = 2t \div 3 = \frac{2t}{3}$$


text:
User:TanmoyKonar

Ductile Material vs. Brittle material:
a)	A material which can undergo considerable deformation before failure is called ductile material. On the other hand, brittle materials are those materials which show small deformation before failure.

b)	A major portion of deformation of a ductile material is plastic deformation, but a brittle material ruptures with very little or no plastic deformation.

c)	The failure of a ductile material is gradual, whereas, the failure of a brittle material is instantaneous.

d)	The examples of ductile material are mild steel, copper, synthetic polymer etc. On the other hand, cast iron, concrete, chalk etc. are the name of some brittle material.

Working Stress Method vs. Limit State Method:
a)	In working stress method the stresses developed within the structural members under different working conditions and load combinations are kept below the permissible stress which is derived after providing adequate factor of safety on the material strength. On the other hand, in limit stress method the stresses developed within the structural members under different combinations of factored loads are kept within the design strength of the materials which is obtained by providing appropriate partial safety factor on the characteristic strength of the materials. At the same time necessary provisions are made to satisfy the serviceability requirements.

b)	Working stress method is a deterministic approach as it is presumed that loads on the structure and material strength are known, though it is not the actual case. In limit stress method, loads on the structure and material strength are determined statistically, i.e., on the basis of observations taken over a period of time.

c)	In working stress method, factor of safety is applied only on the material strength, but in limit stress method, partial safety factors are applied on characteristic load as well as material strength.

Under Reinforced Section vs. Over Reinforced Section:
a)	Under sufficient loading, in a Reinforced Concrete Section, if the reinforcement under tension yields before the concrete crushes, the section is called Under Reinforced Section. On the other hand, in an Over Reinforced RCC section the concrete crushes before the reinforcement under tension yields when subjected to sufficient loading.

b)	The failure of a RCC member with Under Reinforced Section is a ductile failure as it shows large deformation before collapse, whereas, the failure of a RCC member with Over Reinforced Section is a brittle one as it collapses suddenly.

c)	In a single reinforced section the depth of neutral axis is more than the half of the effective depth of the section when the section is under reinforced one, but for over reinforced section the depth of neutral axis is less than the half of the effective depth of a single reinforced section.

d)	During RCC design ‘Under Reinforced Sections’ are commonly chosen over ‘Over Reinforced Sections’ as it induces more ductility to the structure.

Un-cracked Section and Cracked Section:
At small loads, when the maximum tensile stress in concrete is less than its modulus of rupture, the entire section acts as a homogeneous section with compression on one side and tension at other side. This section is called Un-cracked Section.

On the other hand, when tensile stress in concrete exceeds its modulus of rupture, it is assumed that all of the concrete on tension side has cracked and the section is designated as Cracked Section.

One-way Slab vs. Two-way Slab:
a)	When the load applied on a slab is distributed in one direction, i.e., in shorter direction, it is called One-Way Slab, but when the load applied on a slab is distributed in both the direction, i.e., longitudinal and transverse, it is called Two-Way Slab.

b)	When the length of a slab is more than twice of its breadth, the slab is called one-way slab. Otherwise, it is a two-way slab.

c)	One-way Slab carries load though beam action, but in Two-way Slab load is transferred though plate action and hence the deflections and bending moments in Two-way Slab are considerably low as compared to those in One-way Slab.

d)	In One-way Slab, the reinforcement provided along shorter direction carries load but the reinforcement provided along longer direction is distribution steel, whereas, in Two-way Slab the reinforcement provided in both the direction carries load.

Short Column vs. Long Column:
a)	A short column is one which will fail, under sufficient loading, due to development of compressive stress which is more than the compressive strength of the material it made of.

On the other hand, a long column is one which will fail, under sufficient loading; due to buckling of the column much before the material reaches its compressive stress caring capacity.

b)	The strength of a short column is determined only by the material it made of, but the strength of a long column depends on the material it made of as well as on the geometry of the column; more preciously the slenderness ratio of the column.

c)	For a RCC column if the ratio effective length to lateral dimension in both the direction is less than 12; otherwise it will be a long column.

It may be noted that the critical slenderness ratio, which differentiates between short column and long column, depends on the material of the column. For example it is approximately 100 for steel, 40 for aluminum, 18 for wood.

title: User:TanmoyKonar


text:
User:Chubby kerl

Im a ambitious young n clever girl. Im also a christian. I like helping pple especially young kids who are still learning .Im grade 8 n i would truly like to get a busury one day.

I'd like to see myself being a doctor ,healing pple ,saving lifes,

Intro:Abongiwe Mahlangu Age:13(2020) Date of birth:2007 03 11

Im also a christian. I love God n i wish i could have my own church one day.I believe he is the Creator of everything or of the universe

title: User:Chubby kerl


text:
User:Karlhof26/sandbox

Test

title: User:Karlhof26/sandbox


text: File:Electronic-security artwork (lock & circuit-board patterns).jpg


text:
User:Vuyolwethu Skepe

Wikibooks is the grate social miedio app that can you you just need a sometimes it will be famous like Facebook and what's app

title: User:Vuyolwethu Skepe


text: Category:Book:Free Knowledge Culture Calendar


text:
Linux Basics/Package management

What is Package Management?
With package management, a special program called a Package manager is used to install, update, and remove applications. While it's still possible to install programs outside the package manager, the package manager can reduce the day to day work of the user, making it ideal for most software installations on a Linux based system.

One way to think about package management is to compare using an app store instead of downloading a program executable (Like a .exe) from a website. App stores can list installed applications, and update them from a centralized location, while individual programs typically only concern updates with themselves, if they even have an updater function. Unlike an app store, most package managers on Linux distros are completely free, and often predate their proprietary app store counterparts.

Using a package manager
There are a number of package managers for Linux, but apt is among the most common, due to its use in Debian and most of its derivatives.

- updating package list under Ubuntu

 * repositories can be added to package list
 * we use apt mostly instead of dpkg under Debian-based Linux.

Program / package installation:  /

dpkg won't indicate the dependency, so you have to install those that's not on the system. The dpkg, rpm, apt, apt-get etc. commands have man guides (man = manual)

title: Linux Basics/Package management


text:
User:Mahamat.1

Je m'appelle Ahmat Mahamat Ali

title: User:Mahamat.1


text:
User talk:Msangjunboon2018

DISCUSSION.

title: User talk:Msangjunboon2018


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1938 10

Link to Issue PDF
| WorldRadioHistory.com's scan of | Australasian Radio World - Vol. 03 No. 6 - October 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 10

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

October 10, 1938; Vol. 3 - No. 6; Price, 1/-

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

Cover Photo: Photo of Main Studios of Station KEHE Los Angeles (See Page 8.)

Highlighted Contents: "1938 Outdoor Portable": "Ultra-Searcher" for U.H.F. Reception: Adding an R.F. Stage to the "Atlas All-Waver": "1938 Amateur Communications Eight": Latest World S.W. 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. 3. - OCTOBER, 1938 - No. 6.

P.02 - Contents
CONTENTS:

"1938 Amateur Communications Eight". . . . 3

"1938 Outdoor Portable Four". . . . 6

Adding A Tuned R.F. Stage To The "Atlas All-Waver". . . . 10

Portable Transmitter Taken On Radio Hike. . . . 12

EMI Makes Good Indicator For Absorption Frequency Meter. . . . 15

A.O.C.P. Questions And Answers. . . . 17

The Ultra-Searcher. . . . 20

Radio Book Reviews. . . . 22

Contest Winner VK2ADE Operates De Luxe Station. . . . 24

The "Ultra-Shorts" In Review (2). . . . 25

Getting That Trophy-Winning "Verie". . . . 28

1.4-Volt Valves Announced In States. . . . 30

What's New In Radio. . . . 32

Building The A.C. Version Of The "Air-Ace Communications Four". . . . 36

All-Wave All-World DX News. . . . 39

Shortwave Review. . . . 40

Hourly Tuning Guide. . . . 44

Result Of Fifth DX Contest. . . . 45

O. Washfold Wins QSL Card Contest. . . . 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)


text:
Free Knowledge Culture Calendar/February 1

Today in 1992 the Linux kernel was put under GNU General Public License (GPL) to enable its use for the GNU operating system.


text:
Free Knowledge Culture Calendar/March 22

 Today in 1987 Richard Stallman released the first public version of the GNU Compiler Collection (GNU C Compiler, GCC).


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1938 11

Link to Issue PDF
| WorldRadioHistory.com's scan of | Australasian Radio World - Vol. 03 No. 7 - November 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 11

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

November 10, 1938; Vol. 3 - No. 7; Price, 1/-

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

Cover Photo: Photo of Draughtsman, Engineering Department, A.W.A. (See Page 8.)

Highlighted Contents: Assembling and Aligning the "1938 Outdoor Portable Four": More about the "1938 Amateur Communications Eight": Nineteen-Range Combination Vacuum Tube Voltmeter & Multi-Meter: Latest S.W. 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. 3. - NOVEMBER, 1938 - No. 7.

P.02 - Contents
CONTENTS:

Nineteen Range Combination Vacuum Tube Voltmeter And Multi-meter. . . . 3

17-Watt Amplifier Uses Push-Pull 6L6G's. . . . 8

Adding A Pentode Stage To The Atlas All-Waver. . . . 10

Aerial Beacon Erected On Ever Ready Building. . . . 12

Planning Radio Set Sensitivity. . . . 14

New Perth Transmitter Now On Air. . . . 16

Assembling And Wiring The 1938 Amateur Communications Eight. . . . 17

Assembling And Wiring The 1938 Outdoor Portable Four. . . . 21

CFGP Is British Empire's Most Northern Station. . . . 29

The "Ultra-Shorts" In Review. . . . 30

Coil-Winding Data For Philips EK2G Octode. . . . 31

Unique Home Recording Demonstration. . . . 32

What's New In Radio. . . . 34

Radio Book Reviews. . . . 36

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

Shortwave Review. . . . 38

Hourly Tuning Guide. . . . 43

DX News And Views. . . . 45

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)


text:
History of wireless telegraphy and broadcasting in Australia/Topical/Publications/Australasian Radio World/Issues/1938 12

Link to Issue PDF
| WorldRadioHistory.com's scan of | Australasian Radio World - Vol. 03 No. 8 - December 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 12

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

December 10, 1938; Vol. 3 - No. 8; Price, 1/-

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

Cover Photo: Photo of Power Supply Section of the two S.T.C. 10-kilowatt transmitters for 2FC and 3LO (See Page 8.)

Highlighted Contents: "1939 Sky-King Dual-Wave Five" uses latest 6K8-G Converter: Home Recording for the Amateur: Direct-Reading Resistance and Capacity Bridge: Five-Band Transmitter: "Hi-Fi" Speaker Baffle.

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. 3. - DECEMBER, 1938 - No. 8.

P.02 - Contents
CONTENTS:

The "Sky-King Dual-Wave Five". . . . 3

Resistance And Capacity Checker. . . . 6

Tasma 1.4-Volt Valve Receiver Gives Outstanding Results. . . . 7

More About The 5-Metre Super-Gainer. . . . 10

"Hi-Fi" Speaker Baffle. . . . 12

Radio For Bush Search Parties. . . . 14

Waverley And Hurstville Radio Club Notes. . . . 16

Improved Performance From 6K8G Converter. . . . 17

Home Recording (1). . . . 21

World Shortwave Stations. . . . 23

5-Band 10- To 160-Metre 'Phone And C.W. Transmitter. . . . 29

What's New In Radio. . . . 34

All-Wave All-World DX News. . . . 41

Shortwave Review. . . . 42

Hourly Tuning Guide. . . . 46

5- And 10-Metre Transmitter Next Month. . . . 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)


text:
Free Knowledge Culture Calendar/March 31

Today in 1998 Netscape Communicator 5.0 source code was released to developers.


text:
Free Knowledge Culture Calendar/August 22

Today in 1988 the board of the IEEE approved the first edition of the POSIX standard.


text:
User:TiffanyLF/sandbox

This is a page created for a community college class in which I am learning about wikis.

title: User:TiffanyLF/sandbox