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20171210 - NewsWest for Sunday 10 December 2017

posted Dec 9, 2017, 1:59 AM by News Team

Introduction


In the news this week we look deep into the history of amateur radio with reports on the modes we know and love and some that might come as a surprise. Bob checks out CW and Slow Scan TV, Glynn lifts the lid on SSB and FM and I delve into Hellschreiber and JT modes. We'll also cover what's happening in amateur radio across Western Australia in the present time. Roy digs into the goodies back for some bargains and more.


Originating in Perth Western Australia this is NewsWest, produced by WA Amateur Radio News for listeners on-air, on-line and on-demand. I'm Onno VK6FLAB.


You can tune into this news on-air across many amateur frequencies, download the show from vk6.net or subscribe via your favourite podcast application, whichever way you're listening, whether you're a licensed radio amateur or not, experienced or just a beginner, old or young, thanks for being here and thanks for joining us.

Meetings This Week

Go to the VK6.NET website and view the meetings calendar.

History #01 - FM

In telecommunications and signal processing, frequency modulation, or FM is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. This contrasts with amplitude modulation, in which the amplitude of the carrier wave varies, while the frequency remains constant.


In analog frequency modulation, such as FM radio broadcasting of an audio signal representing voice or music, the instantaneous frequency deviation, the difference between the frequency of the carrier and its centre frequency, is proportional to the modulating signal.

Digital data can be encoded and transmitted via FM by shifting the carrier's frequency among a predefined set of frequencies representing digits - for example one frequency can represent a binary 1 and a second can represent binary 0. This modulation technique is known as FSK, or frequency-shift keying. FSK is widely used in modems and fax modems, and can also be used to send Morse code.  Radioteletype also uses FSK.


Edwin Howard Armstrong was an American electrical engineer who invented wideband frequency modulation (FM) radio. He patented the regenerative circuit in 1914, the superheterodyne receiver in 1918 and the super-regenerative circuit in 1922. Armstrong presented his paper, "A Method of Reducing Disturbances in Radio Signaling by a System of Frequency Modulation", which first described FM radio, before the New York section of the Institute of Radio Engineers on November 6, 1935. The paper then went on to be published in 1936.

There are also reports that on October 5, 1924, Professor Mikhail A. Bonch-Bruevich, reported about his new method of telephony based on a change in the period of oscillations, during a scientific and technical conversation in the Nizhny Novgorod Radio Laboratory. Demonstration of frequency modulation was carried out on the laboratory model.


Source: wikipedia

History #02 - Hellschreiber


If you're looking for a digital mode with a century or so of history, you can't go past a mode that was invented in the 1920s. It's name is Hellschreiber, or Hell Writer, not because of it's hotness, but because the inventor Robert Hell wanted to have his name etched into history. It works by sending a series of on-off signals, representing a line, printed twice, so you can even decode the information if there are slight timing errors.


This was the first truly international mode, since anything with a 7x7 grid can be sent using Hellschreiber.


The mode saw use for land-line press services, during WW2 it was used to transmit information and after hostilities ceased, it became increasingly common among newswire services until will into the 1980s.


In the 1990s variations like PSK Hell, used the carrier phase change to encode the brightness of a pixel. FM Hell uses frequency modulation, Duplo Hell uses two tones, CMT Hell uses a mechanism to send all rows at the same time, using different tones for each row, which can be viewed using a waterfall and SMT Hell does a similar thing, sequentially.


You'll find dedicated Hell frequencies on most amateur bands, a few links are on vk6.net [https://www.nonstopsystems.com/radio/hellschreiber-frequencies.htm]

[http://www.qsl.net/wm2u/hell.html] [http://data.w6rk.com/]

[http://www.hamspots.net/hell/]


To use the mode, you can download and install software on your platform of choice, iOS, Android, Linux, MacOS, Windows, Raspberry Pi or Arduino. The link to your radio will be via the sound-card like most of the digital modes today, so if you've got any other Digital Mode running, this is no different.


And if you're looking to actually make contact in Hell, you can. There are nets, DX clusters and QSL cards to be found. No doubt someone has invented an award, but I'll leave that to you to discover.


I should warn you that the speed is 112.5 baud, so typing might be faster, but that said, it's a great mode for experimentation, feedback is immediate and the community is active and supportive.


Hellschreiber, Feld-Hell or Hell, another digital mode, probably a little older than you or I.

History #03 - SSB

The cover of the January 1948 issue of QST was, well, different. An oscilloscope was pictured, and though it was a piece of equipment few hams owned or were familiar with at the time, that wasn’t what made the cover so unusual. Rather, it was the strange looking modulated wave envelope displayed on its CRT screen. Or actually, only one side of the modulated wave envelope.


Normally symmetrical about one axis, the envelope was missing one entire half. What was this all about?


In radio communications, single-sideband modulation, or SSB, also known as single-sideband suppressed-carrier modulation, is a type of modulation used to transmit an audio signal by radio waves.


A refinement of amplitude modulation, it uses transmitter power and bandwidth more efficiently.


Amplitude modulation produces an output signal that has twice the bandwidth of the original baseband signal. Single-sideband modulation avoids this bandwidth doubling, and the power wasted on a carrier, at the cost of increased device complexity and more difficult tuning at the receiver.

The first U.S. patent for SSB modulation was applied for on December 1, 1915 by John Renshaw Carson. The U.S. Navy experimented with SSB over its radio circuits before World War I.


SSB first entered commercial service on January 7, 1927 on the longwave transatlantic public radiotelephone circuit between New York and London. The high power SSB transmitters were located at Rocky Point, New York and Rugby, England. The receivers were in very quiet locations in Houlton, Maine and Cupar Scotland.


SSB was also used over long distance telephone lines, as part of a technique known as frequency-division multiplexing, or FDM. FDM was pioneered by telephone companies in the 1930s. This enabled many voice channels to be sent down a single physical circuit, for example in L-carrier. SSB allowed channels to be spaced just 4,000 Hz apart, while offering a speech bandwidth of nominally 300–3,400 Hz.


Amateur radio operators began serious experimentation with SSB after World War II.  On the night of September 21, 1947, bizarre sounding voices appeared on the 75 meter phone band. These strange signals were audible in California and adjacent states. In fact, they came, not from outer space as some might have thought, but from W6YX , the club station of Stanford University, operated by O. G. Villard, Jr., W6QYT.


No doubt there were listeners out there who could not believe their ears. But what they were hearing was actually single sideband modulation. This event represented the beginning of the postwar SSB revolution in amateur radio. It was said to be the most important technical development to hit the hobby since spark gave way to CW. As we have seen, its implications have gone far beyond the technical.


The Strategic Air Command established SSB as the radio standard for its aircraft in 1957. It has become a de facto standard for long-distance voice radio transmissions since then.


On VK6.net, we’ve linked to a number of interesting articles if you’d like to read further.


Source: ARRL – Amateur Radio and the Rise of SSB

Source: A Short History Of Single Sideband In Amateur Radio

Source: wikipedia

History #04 - Slow Scan TV

Slow Scan television (SSTV) is a picture transmission method used mainly by amateur radio operators, to transmit and receive static pictures via radio in monochrome or color.


A literal term for SSTV is narrow band television. SSTV usually only takes up to a maximum of 3 kHz of bandwidth. It is a fairly slow method of still picture transmission, usually taking from about eight seconds to a couple of minutes, depending on the mode used, to transmit one image frame.


Since SSTV systems operate on voice frequencies, amateurs use it on HF, VHF and UHF radio.


The concept of SSTV was introduced by Copthorne Macdonald in 1957–58.  He developed the first SSTV system using an electrostatic monitor and a vidicon tube. In those days it seemed sufficient to use 120 lines and about 120 pixels per line to transmit a black-and-white still picture within a 3 kHz phone channel. First live tests were performed on the 11 Meter ham band – which was later given to the CB service in the US. In the 1970s, two forms of paper printout receivers were invented by hams.


Slow Scan Television is more common than people may think.  Consider all those years ago when we were seeing photos taken  in space - these images were transmitted to Earth via a slow scan TV system.


Commercial systems started appearing in the United States in 1970, after the FCC had legalized the use of SSTV for advanced level amateur radio operators in 1968.

SSTV originally required quite a bit of specialized equipment. Usually there was a scanner or camera, a modem to create and receive the characteristic audio howl, and a cathode ray tube from a surplus radar set. The special cathode ray tube would have "long persistence" phosphors that would keep a picture visible for about ten seconds.

The modem would generate audio tones between 1200 and 2300 Hz from picture signals, and picture signals from received audio tones. The audio would be attached to a radio receiver and transmitter.


A modern system, having gained ground since the early 1990s, uses a personal computer and special software in place of much of the custom equipment. The sound card of a PC, with special processing software, acts as a modem. The computer screen provides the output. A small digital camera or digital photos provide the input.

History #05 - JT modes

As radio amateurs go, the age of 76 is not uncommon. If you add astrophysicist to the resume, the field narrows, but if you add Nobel laureate to that, you've joined a pretty select group of individuals. Joseph Hooton Taylor Jr., better known as Joe K1JT, or previously Joe VK2BJX is the person behind the first release of a piece of software called WSJT in 2001.


The software made it possible to use extremely weak digital signals across amateur radio using various Digital Signal Processing techniques. It incorporates many different modes or variants which continue to be improved and modified. The software can deal with moon bounce, Ionospheric scatter across all amateur bands and is able to decode fraction-of-a-second signals reflected off an ionised meteor trail as well as signals 10 dB below the audible threshold.


In April of 2010 Joe and his friends went to Arecibo Observatory in Puerto Rico to have some fun. They used the observatory to conduct some 70cm moon-bounce experiments using various modes, including SSB, CW and JT65. You can read about their adventures online, check the link on vk6.net. [http://physics.princeton.edu/pulsar/K1JT/Moonbounce_at_Arecibo.pdf]


Since 2001 WSJT has undergone several major revisions, including making the source-code available under an Open Source license and today the most recent version WSJT-X includes advanced rig-control and several more modes such as the increasingly popular FT8 mode. Version 1.8.0 was released on the 27th of October 2017 and adds and fixes lots of different things. The link to the Release Notes is on vk6.net [http://physics.princeton.edu/pulsar/K1JT/Release_Notes_1.8.0.txt]


To give you some idea, the new FT8 mode gives a 50% or better decoding probability down to -20 dB on an AWGN channel. [https://en.wikipedia.org/wiki/Additive_white_Gaussian_noise]


History is being made every day in Amateur Radio, sometimes it's a century old, other times it was just over a month ago.

History #06 - CW

To transmit messages across telegraph wires, in the 1830s Morse and Vail created what came to be known as Morse code. The code assigned letters in the alphabet and numbers a set of dots (short marks) and dashes (long marks) based on the frequency of use; letters used often (such as “E”) got a simple code, while those used infrequently (such as “Q”) got a longer and more complex code. Initially, the code, when transmitted over the telegraph system, was rendered as marks on a piece of paper that the telegraph operator would then translate back into English.


Rather quickly, however, it became apparent that the operators were able to hear and understand the code just by listening to the clicking of the receiver, so the paper was replaced by a receiver that created more pronounced beeping sounds.


The original amateur radio operators used Morse code exclusively since voice-capable radio transmitters did not become commonly available until around 1920. Until 2003, the International Telecommunication Union mandated Morse code proficiency as part of the amateur radio licensing procedure worldwide.


However, the World Radiocommunication Conference of 2003 made the Morse code requirement for amateur radio licensing optional.  Many countries subsequently removed the Morse requirement from their licence requirements.


Over several years from 1894, the Italian  Marconi adapted the newly discovered phenomenon of radio waves to communication, turning what was essentially a laboratory experiment up to that point into a useful communication system.   


After Marconi sent wireless telegraphic signals across the Atlantic Ocean in 1901, the system began being used for regular communication including ship-to-shore and ship-to-ship communication.


With this development wireless telegraphy, came to mean Morse code transmitted by radio waves. The first radio transmitters, primitive spark gap transmitters used until World War 1, could not transmit audio signals. Instead, the operator would tap out the text message on a telegraph key, which turned the transmitter on and off, producing short ("dot") and long ("dash") pulses of radio waves, groups of which comprised the letters and other symbols of the Morse code.


At the receiver, the signals could be heard as musical "beeps" in the earphones by the receiving operator, who would translate the code back into text. By 1910, communication by what had been called "Hertzian waves" was being universally referred to as "radio",  and the term wireless telegraphy has been largely replaced by the more modern term "radiotelegraphy".

Next Week: New Amateurs

So it’s HISTORY this week for the OLD timers…


Next week… it’s NEW AMATEURS.


What do you know now, that you wish you knew when you first started your amateur radio adventure? What would you do to help mentor newbies wanting to enter the hobby.


We’d love to hear from You.


Send your contribution in for the 12 noon Friday deadline or even earlier if you get the chance.


The address: newswest@vk6.net


If you need a bit of help getting started – flick us an e-mail and we’ll be happy to assist.


If you’d like to submit an audio file, it works best as a 256 kilo-bit MP3.

Our production team recommend and use Audacity,

it’s FREE, and available for Windows, iOS, and Linux platforms.


Oh yeah… Don’t forget to send us a text of your transcript.

Ham College Assessments this weekend

Well the Foundation licence course has come and gone and that was followed by assessments yesterday.  Congratulations to those new hams who shortly will receive their proficiency certificates and in due course a shiny new Licence.  We Welcome them to the hobby and have encouraged them to make plenty of noise!


Don’t forget the last College  meeting for 2017 will be helf this Tuesday night at the Lynwood Scout Hall inside the Whaleback Public Golf Course.

Meeting starts at 6pm and all are welcome.


That from enrolments officer – Andrew VK6AS


As part of our New Ham broadcast next week, we expect to hear from Andrew with a wrap of Ham College results for 2017. I know it’s been a great year.

In the news this week

In the news this week Bob VK6ZGN sent out an email detailing the linking of various connected AllStarLink nodes. Check the vk6.net website for the links to live network status, showing the addition of Kellerberrin, Hoddywell, Katanning, Mount Barker, Manjimup, Townsville, Albany Tiwi, Perth and more and as it turns out Bob's the cause of all that excitement, going on trips, hooking up repeaters, next thing you know, the whole state will be available via a linked repeater network.


[http://stats.allstarlink.org/getstatus.cgi?42732]

[http://allmon.ddns.net/link.php?nodes=28608,42732,42482,28600,28611,40906,42479,45390,1655,45472,45473]

[http://stats.allstarlink.org/]


Paul VK5PAS lets us know that there are 28 VKFF award winners this week. Congratulations to Hans VK6XN, Brett VK3FLCS, Deryk VK4FDJL, Helen VK7FOLK and Rob VK2FARL. Check the full list on vk6.net.


  • Aaron VK1LAJ

  • Allen VK3ARH

  • Brett VK2VW

  • Brett VK3FLCS

  • Danny ON4VT

  • Dennis VK2HHA

  • Deryk VK4FDJL

  • Garry VK2GAZ

  • Geoff VK3SQ

  • Gerard VK2IO

  • Gerard VK2JNG

  • Hans VK6XN

  • Helen VK7FOLK

  • Ian VK1DI

  • John VK4TJ

  • Jonathan VK7JON

  • Keith VK2PKT

  • Les VK5KLV

  • Liz VK2XSE

  • Marc VK3OHM

  • Mark VK4SMA

  • Neil VK4HNS

  • Nick VK3ANL

  • Rick VK4RF

  • Robert VK2XXM

  • Rob VK2FARL

  • Rob VK4AAC

  • Tad JA1VRY



If you're into FT8 or you need an excuse, check out the Euripean Radio Amateurs' Organisation who are hosting an FT8 party on the 16th and 17th of December, starts at 0:00 UTC running for 48 hours. Details on vk6.net [http://www.eurao.org/en/node/913]


If you'd like to see how to make contact using an amateur satellite, Peter VK3YE has published the Foundation Guide to Amateur Satellites with special focus on AO91. The link to the YouTube video is on vk6.net [https://www.youtube.com/watch?v=astteV2umOg]


And finally, Steve VK6HV is wondering if any of the local clubs or the WIA have a straight key night starting Jan. 1 at 00:00 UTC. He believes ZL may participate as does the ARRL. So, come on, find that old straight key and dust it off!


If you wanted more, you have to do the work. Send an email to newswest@vk6.net with your news story.

Outro

If you'd like to find out more about amateur radio, what frequencies to listen to this news bulletin, copies of the news or read about the stories you heard today and investigate further in the text-edition, head on over to the website at vk6.net where you'll also find information about local repeaters, the club calendar, a feedback button, information about submitting news and information about clubs around Western Australia.


On behalf of WA Amateur Radio News, thank you for your time today. You heard Bob VK6POP, Glynn VK6PAW, Roy VK6XV and I'm Onno VK6FLAB. We look forward to your company next week when we welcome new amateurs to our bands.


We'll be producing the news throughout the silly season, so you won't have to feel alone and we're working on a visit from Santa soon, so check that out. If you have some fond memories to share for 2017, drop us a line, newswest@vk6.net is the address.


73, now get on air and make some noise.

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