history – vk2rh

October 27, 2020November 25, 2020

AMR100

A few weeks ago at the ARNSW Dural site I was talking with Mark Blackmore about the classic radios incorporated into the VK2WI broadcast building. He showed me some beautiful Collins receivers and some Racal sets. Also occupying a position on the equipment rack was a very shiny Kingsley AR7, the famously unauthorised copy of the National HRO receiver produced to supply the Australian Army and the RAAF during the second world war. (I later found a detailed description of the story behind the restoration of what I believe is this actual radio at Ray Robinson’s website http://www.tuberadio.com/robinson/museum/AR7/)

Mark looks after disposal sales for the ARNSW and he had tales of beautiful radios that he had inspected over the years that had been stored in less than ideal conditions. His advice in a nutshell – At the very least just wrap the radio up in a large plastic garbage bag!

This sent a guilty shudder down my spine as I remembered a couple of radios I had acquired a very long time ago that had lived in various storage sheds and cupboards over the decades. But it also prompted me to have a proper look at them over the next week.

Back in the late 1980s I had bought what I thought was an AR7 from a ham in western Sydney. It also had a complete set of plugin coil boxes. I’m ashamed to confess that since buying it I had never once really examined it to check out its condition. I had downloaded copies of the schematic and the operation manual and even the series of articles from Amateur Radio magazine detailing the various modifications many VK hams made to their AR7s in the 1950s and 60s, but I obviously hadn’t gone further. Even more obviously to me now, I hadn’t even read the first few pages of the manual. If I had I might have realised that I had one too many coil boxes!

As soon as I started a new web search into what I thought was my AR7 I realised there were some important differences. While it shared the distinctive HRO style dial, my radio had a different front panel and layout of controls. It was nothing like the shiny stainless steel I could see everywhere. In fact the best indication of what the original finish might have been was in a patch where the boiler plate identification of the radio would have been had it not been removed for some reason. The coil boxes looked quite different as well with small charts under yellowing plastic rather than engraved in the faceplate.

AMR101-front-panel — The front panel of my AMR100 looking like it’s been neglected and crying out for some TLC.

Thanks to some excellent websites about military radios, it didn’t take long to discover the actual identity of my receiver.

Dave Prince VK4KDP via the Royal Signals website https://www.royalsignals.org.uk/photos/vk4kdp.htm confirms the radio I have was in fact made by AWA and was probably painted an attractive green. It’s an AMR100. AMR stands for American receiver as they were made for the US Signals Corps.

On his own page at https://www.qsl.net/vk4kdp/army.html you can also see a very attractive version of how my radio should appear.
Note the AWA logo on the US Signal Corps boiler plate, and the green front panel.

Apparently the AMR100 Receiver was manufactured by AWA in Sydney under licence from National. I’ve read elsewhere that the US Signal Corps in the South West Pacific were having difficulties obtaining HROs from the US and AWA offered to supply them in a form of a reverse lend-lease arrangement.

Dave VK4KDP describes the AMR-100 as “a Single Signal type covering 480 kHz to 26 MHz with 6 plug-in coil boxes”.

Armed with this information I was able to locate two detailed operating manuals for the AMR 100 (the ‘table top’ model) and the AMR101 (the rack mounted version) on Ray Robinson’s encyclopedic site at http://www.tuberadio.com/robinson/Manuals/

http://www.tuberadio.com/robinson/Manuals/AMR100.pdf – a scan of the manual for the desktop model – AMR100 Receiver Type C13500. Ray Robinson refers to it also as US Signal Corps SC-CD-136-43.

http://www.tuberadio.com/robinson/Manuals/AMR101.pdf – which is a version of the manual for the AMR101 Receiver Type C13500R retyped by John Kidd.

I also located a scan of the original AMR101 manual at https://bama.edebris.com/download/awa/amr101/amr101.

My particular radio includes the same team of valves, two 6U7G RF stages, a 6J8G mixer, a 6J5G oscillator, two 6U7G IF stages, a 6G8G multi-tasking as detector, AVC and AF amplifier, a 6J5 BFO and a 6V6G as AF output.

AMR101-inside — The inside of the AMR100 showing added output transformer on top LHS hiding the power supply mod on LHS and missing crystal on RHS

Once I had a closer look inside the radio it was apparent that a few modifications had been made to the receiver. Where I imagine the 6J5 BFO was originally located – based on markings on the painted chassis – is now occupied by a 5Y3GT which looks like part of an added power supply. The BFO is re-located on a bracket installed beneath the chassis using a metal 6J5 valve.

I suspect the 455 kHz crystal has been removed. I have to check whether an FT243 style crystal might fit. It may need some kind of adaptor.

AMR101-under-the-chassis — Underneath the chassis of the AMR100 showing the general condition of components and wiring. The black metal 6J5 valve for the BFO can be seen on the lower LHS near the BFO inductor.

Once tidied up the chassis is remarkably clean, top and bottom. Some of the valves bulbs have come loose from their bases. All the valve screens are present and seem okay.

AMR101-rear-view-of-chassis — The was a shot of the AMR100 chassis after it was removed from its case and before any cleaning

Overall the condition of the wiring is probably the main cause for concern. The rubber covering is now brittle and much has broken away from the wire. It looks as if it will all need to be replaced. I expect all the paper capacitors and electrolytic capacitors will need to be replaced.

AMR101-under-chassis-wiring — A closer view under the chassis of the AMR100 showing the condition of the wiring and the vintage and condition of the components

If I don’t keep the 240 VAC power supply modification I will need to find or build a separate power supply capable of delivering about 270 VDC at 75 mA and 6.3 V at about 3 A. That shouldn’t be too difficult.

I suppose the first stage of assessing what to do next (and even whether) to restore the receiver is to check the continuity of all the inductors.

AMR101-power-supply-mod — After removing the speaker output transformer the power supply modification can be seen with the 5Y3GT valve where the 6J5GT BFO valve was originally installed. The tag strip of resistors above the transformer are for setting the various ranges of the front panel meter.

April 13, 2018April 14, 2018

Australian Code Breakers

On Wednesday evening I went along to a talk at a nearby library by David Dufty about his recent book ‘The Secret Code-Breakers of Central Bureau – How Australia’s signals intelligence network helped win the Pacific War’ published last year by Scribe.

The Secret Code-Breakers of Central Bureau by David Dufty

It’s a great story that does uncover previously unacknowledged contributions. Dufty’s interest was sparked by a newspaper mention of Australian wartime code-breaking on Anzac Day 2012. His interest triggered a comprehensive research trail.

It’s a great read with a solid bibliography. He interviewed about twenty people who worked on breaking the Japanese codes. From a standing start, the operation grew to involve over 4,300 Australians – a venture, Dufty says, it’s hard to imagine us being able to mount as readily today.

He mentioned many of the characters from Australia’s early radio history, including Mrs Mac, Florence MacKenzie, who trained thousands of women morse operators who in turn were used to train many Australian servicemen.

He also mentioned Eric Nave who was responsible for breaking Japan’s Naval codes. Nave as a young naval cadet had spent years in Japan learning the language and culture of the country.

The character with the best nickname would have to be Keith ‘Zero’ Falconer. He was the country’s top interceptor of Japanese Kana coded messages. He got the nickname from his colleagues as every single day of Kana code training in Melbourne he would score zero errors in the test. Japanese hams can still be heard conversing in this code on the bands today.

The character who stands out from David Dufty’s talk on Wednesday evening is Stan or Pappy Clark. Apparently, prior to enlistment, his work was scripting radio serials for children. The mention of the magic word radio was enough to catch the eye of people recruiting for radio intelligence work, and it turned out to be a fortunate selection for Australia.

Stan Clark used his talents to develop a comprehensive knowledge of the Japanese communication networks and was able to analyse the dynamic ebb and flow of their radio traffic. Even if we weren’t able to decode every message the broad overview – which Dufty interpreted as the ‘metadata’ of the enemy’s radio communication – of this traffic analysis played a crucial role in determining the allied strategy of the war and effectively saved thousands of allied and enemy lives. Macarthur’s famous island hopping strategy was directly informed by this intelligence. One of the special things about Wednesday night was that unknown to Dufty until the end of his talk, Clark’s grandson and family were in the audience.

April 10, 2018April 14, 2018

Learning morse and touch typing in tandem

I’ve been wondering whether I should try to synchronise my most recent efforts at learning and improving my morse with a similar complementary neural mapping exercise of simultaneously learning to touch type as I practice copying morse code.

I was googling around – on the off-chance someone had developed the ultimate piece of software which combined G4FON Koch CW Trainer with Typist or some other touch type trainer, oh and for the Mac would be good – using the term “learning morse and to touch type at same time” and I discovered via Google Books Lewis Coe’s ‘The Telegraph’. Here on page 109 is mention of how operators could recognise their call in their sleep!

The highlighting is due to the google search term.

On pages 69-70 there’s mention of how the older operators used a mill to take down messages as they streamed in over the line.

Maybe the best approach would be to change the learning sequence of characters to match the character sequence of touch typing so that every character gets a double whammy of learning reinforcement. So F, J, D, K, S, L, A and ; (?) instead of K, M, R, S, U, A, P, T, L and O.

It shouldn’t be too hard to generate suitable static mp3 audio files of the touch type progression of characters. It would be great if there was a way to randomly generate according to this new progression, in a similar way to the G4FON software, with the alternate character sequence.

Also, I’m sure someone somewhere must have considered the learning pros and cons of such an approach.

I also found the perfect font to use. It’s called MILL

You can grab this TrueType font from http://www.qsl.net/n1ea/MILL.ttf.

Not quite the same as this one which explains its own provenance:

October 4, 2017October 5, 2017

Sputnik 60 years ago today

One of the clearest memories of my childhood is being taken up our steep driveway to the roadside out the front of our house from where there was a commanding view of the western and the southern sky. Sixty years ago today the Russians launched Sputnik and it would have been a few days after this that my father took me as a seven year old boy to watch as the satellite passed over Sydney. He must have chosen a clear night because I do remember seeing it as a fast moving bright light. What was even more impressive was that then my father took me back inside and turned on our radiogram and switched over to the shortwave bands and seemed to know exactly where to tune the radio to pick up the beeping sound of the satellite’s radio signal. The Sydney Morning Herald has just republished its coverage which captures the local mood at the time.

A Russian 400 kopeks stamp showing the Sputnik’s orbit around the Earth

There are youtube videos online claiming to reproduce the actual sound of the sputnik.
Wikipedia links to this sound, but the authenticity of this too is challenged. From the wikipedia entry on Sputnik 1 I learned that there is a direct link between the satellite and the internet. The launch was brought forward to sync up with and maybe upstage the IGY – International Geophysical Year – which began in July 1957. The Soviet success and the US failure with Vanguard led to a major reassessment of the US approach to science & technology. One of the first responses from the US to this challenge to their technological and scientific prestige was to set up ARPA Advanced Research Projects Agency, later DARPA in February 1958. Australia followed the US lead. My generation saw a boost to science education. One of the scientists quoted in the Sydney Morning Herald report, Harry Messel, went on to edit the amazing ‘Science for High School Students’ textbook for high school which I devoured and almost memorised by heart.

The science textbook Harry Messel convened in the wake of the Sputnik crisis for Australian students.

I stumbled across a 55 minute long documentary on Sputnik ‘The Story of the Sputnik Moment’. It’s full of contemporary footage that really evokes the time from the US perspective. From this doco I learned that ‘Leave It To Beaver’ premiered on the same day! This was a popular program in our home – my parents thought I was a double for Beaver, but so did many others as I do remember there was a Beaver lookalike competition even here in Sydney! Anyway this video includes sound of the sputnik. It also echoes in reverse the current impasse with North Korea. There is almost identical footage of marching Soviet troops, admittedly with slightly less energetic steps. But the threat is the same. And the issues impingeing on the technological struggle such as the US civil rights fight remind us the civil war didn’t ever really end.

This is a flight-ready backup of Sputnik 1, on display at the Kansas Cosmosphere in Hutchinson, Kansas

If anything my father seemed more impressed by the achievement than fearful for what it might mean about global nuclear war, but really what would I have known as a seven year old!?! I do remember he had a friend at his work, Tullochs a railway rolling stock and steel building material manufacturer, who was a radio amateur. It was most likely this ham who gave Dad the info he needed to tune into the signals, although I believe it was probably included in newspaper stories. This was probably the same man he took me along to meet after I had started building radios as a 12 year old. I think his name was Bob and he lived in Ermington or thereabouts. I don’t remember his call but I do remember that he had built all his gear and operated exclusively CW on 20 metres into a dipole in his modest backyard, to keep in touch with friends back in the UK where he’d emigrated from.

What I know now as well is that 1957 coincided with the best radio propagation conditions ever. It was the high point of the best solar cycle, so the few feet of copper wire hanging in the air as an antenna would have had no trouble pulling in the 1 watt signal from Sputnik. And of course background interference would have been minimal compared to today. So maybe I’m mostly nostalgic for the quieter and yet more lively radio conditions of times past.

What’s great about this memory is that it’s clear my father had a strong sense of the significance of the event and my potential interest. Even though he wasn’t a technical person he was quick to sense my interests and encourage them. Maybe it would have been hard to miss noticing the young me in the backyard hammering away at a piece of metal downpipe trying to fashion a rocket nose cone! From this day on I remember being given How and Why Wonder Books about rockets and science, and avidly collecting cards from Nestles chocolates for their ‘Adventure in the Sky’ album.

Cover of ‘Adventure in the Sky album published by Nestle to encourage kids like me to buy more chocolate bars to collect images of planes and rockets!

From reading about the launch it’s apparent that what we probably actually saw was the larger remnant of the R-7 rocket that followed the satellite into orbit. It was first magnitude compared to the Sputnik’s sixth magnitude size and brightness in the night sky. That knowledge however doesn’t dim the excitement I remember.

June 3, 2016September 27, 2016

Walter Winchell

I was meandering around the web this morning and stumbled on to a page where famous key collector and curator Tom Perera W1TP had re-created the morse key setup used by Walter Winchell to introduce and punctuate his radio and later TV broadcasts. They were a pair of Vibroplex bugs.

The Vibroplex ‘Lightning Deluxe’ and ‘Original’ bugs

I grew up in Sydney in the 1950s and remember how radio station 2UE would start their news bulletins with a brisk CQ CQ. They were probably inspired by Winchell. Another memory is watching ‘The Untouchables‘ on TV with narration by Walter Winchell.

It’s worthwhile reading Walter Winchell’s Wikipedia entry while you listen to and occasionally watch an archived TV show of his from December 1953.

Ironically in his early years as a gossip journalist he was close to prominent criminal identities and later became friends with J. Edgar Hoover. He was Jewish and in the lead up to the second world war was one of the first Americans to criticise Hitler and those in the US who supported him. Another of his targets was isolationist Charles Lindbergh. His fame followed his reporting the famous kidnapping and subsequent trial.

From the clip you can hear the rapid-fire delivery. In many ways it’s like a precursor to much of what we consume today.

Walter Winchell reporting – from a brilliant site about old mics – coutant.org

He attacked the Klan and its supporters. After the war he aligned himself with the Senator Joe McCarthy’s hunt for communists. But within this short clip there are a couple of places where he briefly questions a couple of issues that were to haunt the US for the next couple of decades – Vietnam and cigarettes and cancer.

Complex and probably unattractive, what I want to know is if he actually knew how to handle those Vibroplex keys.

May 8, 2015September 28, 2016

Roll your own valves (tubes)

A few weeks back – in the post about wartime crystal production – I made a tangential reference to my all time favourite YouTube video – Claude Paillard F2FO distilling down to less than 20 minutes his meticulous work making a triode valve, effectively by hand. Watching it again, this time I spent a bit more time looking over the many pages of background information he had posted on his website detailing his research into triodes of the 1920s, the techniques he used and the equipment he used or made to complete this project and create a very cute looking valve wearing blue shorts.

This prompted me to start a more methodical reading of the documents, and to work through the translations to ensure I understood what he had done. (Google translate is great, but it missed a significant amount.) If you’re vaguely interested in the technology of the earliest days of radio, and have ever wondered how these valves were made, the documents take you on a special journey through the eyes of an explorer with a brilliant workshop and skills to match. His research is comprehensive. By way of exploring how early valves were made he produces a full detailed and illustrated life story of the evolution of valve types and introduces important valve families like the 6L6 and its descendants like the 6V6 and the 807 of the late 1930s. He also takes you on an excursion to discover the history of creating an effective vacuum, critical in the creation of the valve aka the vacuum tube.

It’s also an enjoyable way to build up a French vocab for the terminology of valve radio gear. Along the way I stumbled across the Electropedia, a brilliant resource for translating technical terms from French to English with a number of other languages included. But some of the terms Claude Paillard uses reflect an earlier era and vocabulary. He talks about the plaque (plate) of a valve rather than l’anode. I’d love to find online versions of the French radio engineering references he cites from the 1920s.

Edouard Cliquet wrote a number of books explaining radio

Another plus of this experience is reading the history of radio from the perspective of a country other than Britain or the US. The French version of radio history introduces interesting characters and stories to the familiar names and places. An inspiration behind the work of F2FO is the history of the triode TM (Télégraphie Militaire). A good outline is at Michel Siméon’s website.

Pratique et théorie de la T.S.F by Paul Berché

Paul Berché was another prolific author of French radio texts.

April 2, 2015September 29, 2016

Grinding quartz and holding a frequency during World War II

I’m a great fan of the Prelinger Archives which is home to so many items like this video I’ve heard about recently from various ham radio email lists.

I like how the components of the earliest electronics and wireless were so basic and ‘natural’. Think of hand made capacitors and resistors using traces of graphite on paper. Valves (or tubes) of course were another story but still capable of being ‘homemade‘.

I love the idea that an accurate, literally rock solid frequency could be achieved using a piece of a very common rock – admittedly a pure piece of quartz cut just so.

This video details the elaborate and meticulous manufacture of quartz crystals during World War 2 by Reeves Sound Laboratories in 1943.

The 41’24” video can also be viewed (free of youtube ads etc) and downloaded via the Prelinger Archives.

Most of the ‘radio quality’ quartz was mined in Brazil which ceased its neutrality in 1942 and joined the Allies.

The story of quartz crystals during WWII is told in ‘Crystal Clear‘ by Richard J. Thompson Jr. (Wiley) 2011.

The cover of the book "Crystal Clear - The Struggle for Reliable Communications Technology in World War II" by Richard J Thompson Jr. — “Crystal Clear – The Struggle for Reliable Communications Technology in World War II” by Richard J Thompson Jr.

“In Crystal Clear, Richard Thompson relates the story of the quartz crystal in World War II, from its early days as a curiosity for amateur radio enthusiasts, to its use by the United States Armed Forces. It follows the intrepid group of scientists and engineers from the Office of the Chief Signal Officer of the U.S. Army as they raced to create an effective quartz crystal unit. They had to find a reliable supply of radio-quality quartz; devise methods to reach, mine, and transport the quartz; find a way to manufacture quartz crystal oscillators rapidly; and then solve the puzzling “ageing problem” that plagued the early units. Ultimately, the development of quartz oscillators became the second largest scientific undertaking in World War II after the Manhattan Project.” (from the book’s blurb)

Illustrating the precise angles needed for the AT and BT cuts of a quartz crystal…

November 1, 2012September 29, 2016

Hidden heroes

The BBC have just broadcast and put on YouTube an excellent hour long documentary about two people whose wartime work is credited with shortening the war and saving millions of lives. Yet because of the cold war and the climate of secrecy, credit came late or not at all.

‘Code-Breakers: Bletchley Park’s Lost Heroes‘ details the work of young mathematician Bill Tutte who broke the German’s top-secret Lorenz code and Post Office engineer Tommy Flowers who built the first electronic computer ever – to replace ‘Heath Robinson’, the mechanical device used to process the code-breaking.

Bill Tutte and Tommy Flowers were both ‘scholarship boys’ who benefitted from the best educational and research opportunities available to their generation. Earlier conflicts may not have been able to discover and develop such talents. (And it’s questionable whether comparable educational opportunity is available today.)

It’s hinted towards the end of the program that the extended secrecy about their achievements is connected to the assumption that the Soviets continued to use the captured German Lorenz system into the 1950s. You can only imagine Tommy Flowers’ frustration, biting his tongue every time someone referred to ENIAC as the first computer!

You have to marvel at the beautiful minds of these two men – dealing with complex matrices and patterns and the logic associated with understanding them – without the tools we take for granted today. One of my favourite scenes is Bill Tutte at his desk with a hand drawn grid on a large sheet of paper tracking the pattern of the characters in the coded messages.

May 11, 2011September 29, 2016

Winnie the war winner

The other day I noticed a very interesting photo on a fellow Australian ham blogger, Peter Mark’s site. The blog entry was titled a “Radio nerd’s tour of Canberra“. The first photo is described as ‘a transceiver with a nifty antenna tuner’. But the instant I saw it I sensed there was slightly more to it.

The fact that it was built on a beaten up old kerosene can prompted me to google “Winnie the war winner” and the results confirmed Peter’s photo is of this most famous piece of Australian ham homebrew ingenuity. Max (Joe) Loveless’ skill to be precise. The photo prompted me to find out the story of this iconic wireless set that’s an inspiration to a generation of Australian radio hams proud of their traditions of ‘making-do’.

The wikipedia entry on the Battle of Timor gives detailed historical and military background to this little radio’s moment of fame in April 1942.

As a result of British intrigue Australian troops were sent to Portuguese East Timor to disrupt any Japanese invasion on Australia’s northern doorstep. By April the 2/2nd Independent Company had been fighting a guerilla campaign for four months. Many were ill and they were low on supplies, and had had no contact with Australia since February.

For weeks a team had been trying to build a transmitter from salvaged parts from damaged radio gear. Before the war Max Loveless was a radio amateur in Hobart with the call 7ML. He became a Signaller with “Sparrowforce” on the Dutch part of Timor with the Australian Infantry Forces (AIF).

Report on Winnie the war winner in the Melbourne Argus for 1 Jan 1943 - page 12 — Report on Winnie the war winner in the Melbourne Argus for 1 Jan 1943 – page 12

Bill Marien reported the story in the Melbourne Argus of 1st January 1943:

“Force Intact. Still Fighting. Badly Need Boots, Money, Quinine, Tommygun, Ammunition.”

This was the first official message received in Australia from the lost AIF commandos of Portuguese Timor who, for 59 days after the Japanese landing on the island, had been written off as missing or dead.

The signal came to Darwin on the night of April 19. It was transmitted by “Winnie the War Winner,” a crazy contraption built from scraps of wire and tin, and pieces of long discarded radio sets.

When the commandos showed me the incredible Winnie recently, it was easy to recapture the scene of that night of April 19.

In the thin air of a Timor mountain hideout, 4 bearded, haggard Australians were working by the smoking, stinking light of a pig-fat flare. Three of them watched anxiously as the fourth thumbed a Morse key. Weak batteries sent the dots and dashes of the morse dimly across the Arafura Sea to the Northern Territory of Australia. The tension was something physical as the operator strained his ears for a reply. At last a reply came.”

The AIF commando force which had been in Portuguese Timor were joined by other Australians from Dutch Timor including two signalmen, Cpl John Sargeant, of Bonshaw, NSW, and Lance-Cpl John Donovan, of Lindfield, NSW. Under leadership of Capt George Parker, of Earlwood, NSW, they joined Sigs Max (Joe) Loveless, of Hobart, and K. Richards, of Victoria, both of the original commando force.

“On March 8 the 4 men got to work — Loveless just out of sick bed and Sargeant just recovered from malaria. Three days later a Dutch sergeant, exhausted, stumbled in. He had carried what he thought to be a transmitter-receiver 40 miles through some of the roughest country in the world. It was an ordinary commercial medium-wave receiving set – and out of order.

CORPORAL WENT SCROUNGING

Loveless, whose knowledge made him No 1 man of the team, thought he could build a one-valve transmitter from parts of this set and of another small and weak set. He planned a circuit, and all the commandos were asked to be on the lookout for anything that might serve as a radio part.

Cpl Donovan went scrounging at Attamboa, on the north coast, to see what he could salvage, while his companions recovered an abandoned army set. The parts of the 3 sets were unsoldered, and a bamboo used to catch all the melted solder for re-use. Loveless had carefully preserved 2 small batteries, but they needed recharging. A generator was taken from an abandoned 10-year old car and rigged to a series of wooden wheels, which a native was persuaded to turn. The set was complete on March 26.

It would not work!

Three of the team who helped Max Loveless build Winnie the war winner re-enact transmissions from a hill in East Timor - Signaller Keith Richards, Corporal John Donovan and Lieutenant Jack Sergeant. Photo by Damien Parer — Three of the team who helped Max Loveless build Winnie the war winner re-enact transmissions from a hill in East Timor – Signaller Keith Richards, Corporal John Donovan and Lieutenant Jack Sergeant. Photo by Damien Parer.

The only tools available were a tomahawk, pliers, and screw-driver. They had no test equipment to determine the set’s frequency. The coils were wound on pieces of bamboo.

On March 28 Donovan returned from Attamboa – laden like a treasure ship. He had the power pack from a Dutch transmitter, 2 aerial tuning condensers, 60ft of aerial wire in short lengths, and a receiving set. Next day the men had to move all their precious gear, for the Japanese were getting too close.

Loveless got to work on a second transmitter twice as big as the first, and built it into a 4-gallon kerosene tin. A battery charger was recovered from enemy-held territory. To get it 14 commandos went through the Japanese lines to the old Australian headquarters at Villa Maria. There, within 100 yards of Japanese sentries, protected only by the dark, they dug up the charger which had been buried when the headquarters were evacuated.

HEARD DARWIN WAS SAFE

On April 10 the signallers heard Darwin on the receiver, and knew then that Darwin was still in Australian hands. But their second transmitter was also a failure.

Loveless had another idea, but he needed more batteries. Four were found. Then the petrol ran out and the charger could not be kept running. So they raided the Japanese lines and carried off tins of kerosene. Finally the charger was started on kerosene and run on diesel oil.

With batteries at full strength they signalled Darwin on April 18, but got no reply. They did not know that their message had been picked up on the Australian mainland and passed on to Darwin, that all transmitting stations had been warned to keep off the air and listen to Timor the following night.

You can get a good sense of the story from this video of the documentary ‘The Men of Timor’ filmed in Timor by Damien Parer in late September 1943. You can see a reconstruction of the building of the radio about 3’16″ in from the start.

On the 19th April they heard Darwin but their batteries failed again.

On the night of April 20 they again got Darwin. But Darwin was suspicious; demanded proof of their identity. So questions and answers like these were rushed across the Arafura Sea:

“Do you know Bill Jones?”— “Yes, he’s with us.”

“What rank, and answer immediately?”— “Captain.”

“Is he there? Bring him to the transmitter. . . . What’s your wife’s name, Bill?”— “Joan.”

“What’s the street number of your home?”

Once they provided the correct answers, help was on its way.

I found the newspaper report on the National Library of Australia’s brilliant Trove, where digital versions of many Australian newspapers have been put online courtesy of crowd-sourced editors across the global internet. Truly astounding!

Category: history