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.
“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)
I’m one of those people who learnt morse code completely the wrong way. Starting off in the seventies with no guide I simply tuned into nightly morse transmissions sent by local hams at a very slow rate. I think they started at 5 words a minute. The main risk there was nodding off between words or impatiently guessing the wrong word.
Contemporary wisdom is that you should start listening at a much faster rate, say 15 or 20 words per minute. This is to prevent you counting dots and dashes in your head, and to make it easier for you to recognise the letters, numbers and even words by their sound.
Learning 15 wpm after mastering say 8 wpm is almost like learning a new language. Students of morse talk of ‘a plateau’ at 10 which is a mighty barrier to progressing up to a more useful conversational speed.
My personal goal is to be able to copy and send at 25 wpm and be able to sustain it over a couple of hours, and to be able to read mostly ‘in my head’, only using pencil and paper for details like names and callsigns.
Now that morse code is no longer compulsory for any ham licenses, surprisingly it seems to be more popular than ever! Especially with those hams who like to use low power to make contacts, or to take the lightest possible transceiver to a remote mountain top as part of the global ‘Summits on the Air‘ activity. Morse gets more mileage than voice per watt, and often these tiny transmitters are only putting out a couple of watts power.
And there’s something delightful in having the skill to read the beeps.
But for me it’s a skill I have to keep working on. I think in my twenties I was quite at ease chattering away at about 12 wpm seemingly for hours on end. Four decades on with a large slab of radio silence in between, I’m quite rusty, even though I know the basics are still there like riding a bike.
I’m a bit wobbly at the paddles, having grown up with the old fashioned straight key (the type you’re likely to have seen in old westerns). But you can feel slow but definite progress from every bit of practice you put in.
One of my favourite sites is Martin DK7ZB’s collection of pages detailing the construction of practical antennas for VHF and UHF.
I first visited the site following a link to designs for lightweight portable yagis that would be suitable for SOTA VHF activations. Under the link ‘2m/70cm-Yagis ultralight’, Martin describes a number of yagis for 2m and 70cm that use thin metre long aluminium welding rods mounted on PVC booms.
“These Yagis are constructed with cheap lightweight materials for electric installations and you can mount and dismantle them without any tools. The boom is made of PVC-tubes with 16mm, 20mm or 25mm diameter, the element holders are the clamps for these tubes.” DK7ZB
What makes the designs particularly attractive is that they can be quickly assembled from a compact (admittedly metre long for 2m) pack you can carry on your ascent, even designs using a 2 metre long boom.
The welding rods – used for TIG welding – are available in Australia in 2.8mm and 3.2mm diameters from welding supplies shops. I’m still on the lookout for 4mm diameter rods. PVC conduit and the mounting clamps are readily available in VK from hardware stores.
I’ve managed to cut a suitable slot in the end of a 3.2mm aluminium welding rod using a Dremel with a thin cutting wheel. One suggested way of attaching the feedline to the driven element is to crimp the lines into thin slots like this.
Also of interest to the portable operator are the J Pole designs based on Wireman 450Ω window feedline. There are dimensions for bands from 2m down to 40m. The J pole is essentially a half wavelength dipole where the high feed impedance is transformed by a quarter-wave length matching section (the tail of the J) tapped at a suitable distance to yield a 50Ω match. Follow the ‘Wireman-J-Pole’ link in the left navigation. These pages remind you that the J-pole can be configured in any way so a 40m J pole in a Zepp arrangement starts to look quite practical if you have just under 10m of 450Ω feedline available. I want to start with the 6m design and see if I can make it robust enough with heat shrink etc for portable work.
Kits for the DK7ZB yagi designs are also available from nuxcom.de, Attila Kocis DL1NUX’s website. Both sites are in German and English.
News is just in that SOTA – Summits on the Air – starts in a number of new call areas tomorrow including my home state New South Wales, VK2. I understand that Queensland VK4 and Hawaii KH6 may also be launched tomorrow, 1st September.
The new VK2 association adds over a thousand summits to the SOTA database. I was part of the team that surveyed the 16 regions. Hats off to Andrew VK1DA/VK2UH who coordinated the widely dispersed team of surveyors. I should publish a post here soon about the things I learnt along the way, about the resources available for SOTA summit surveying and cracking the mystery of identifying the all-important saddle to ascertain the required prominence. Flooding Google Maps is the clue.
The news of the scheduled start has taken us a little by surprise. I’m not sure how many activators will have had time to properly plan activations for the first day. The other issue is that tomorrow, Sunday 1st September is Father’s Day.
For more news about the accelerating SOTA activity in Australia – it’s already active in VK1, VK3, VK5 and VK9 – you should follow the conversation on the SOTA-Australia Yahoo group and visit VK1NAM’s blog for a list of SOTA blogs from VK activators.
The WIA’s Amateur Radio magazine for September which arrived in letterboxes yesterday features a report on the mass activations on 11 August celebrating six months of SOTA in VK1 as well as three pages of regular SOTA news. It’s brilliant for SOTA that editor Peter VK3PF is also one of the top SOTA activators in VK.
Yesterday I had my final CW Academy session. As an indication of how good it was and how much we valued it, not one of the five of us ever missed a single session! There were sixteen hour-long sessions over two months. And it was all free!
Late last year I noticed a couple of messages from Jack W0UCE inviting hams keen to improve their CW skills to join in and pointing them to this page detailing the thinking behind CW Academy’s approach.
What was on offer was a series of online sessions in a small online group re-learning the code. The hour-long sessions are designed to get you to read in your head and to break or avoid habits (like writing everything down) that will prevent you from increasing speed later.
The target for our beginner group was around 20wpm. The sessions took place using Oovoo which is like Skype for groups. (Apparently it’s important that the instructor can see who is having difficulties.) We logged on twice a week. In between times we were expected to practice daily using a nifty online tool, Morse Translator. This neat web app lets you practice listening to code and adjust both character speed and Farnsworth spacing. Our default setting from day one was 20wpm character speed with gaps to yield an effective speed of 10wpm. Morse translator is a great model to help practice sending as well. I found including sending practice helped lock in recognition of words.
Our teacher or Elmer was Rob K6RB. He shared his intense enthusiasm for CW with us as well as his experience on air. After a few weeks of walking us through the alphabet, numbers and prosigns and practising new letters and words, Rob gradually upped the speed. Then the rubber hit the road about week five when we were QSOing back and forth. Rob patiently introduced us to the format of the typical QSO, contesting and even handling a DXpedition. His aim was to prepare us for these so that we’d know what to expect and what was expected of us when we joined in. We got the benefits of decades of operating experience in these sessions.
The CW Academy is an initiative of the CW Operators Club. CWops is international in focus and it was great to be accommodated as the token DX in the group. As they say on the webpage “available to anyone, anywhere”.
The training has got me confident to get back on the air with a practical code speed and as a bonus, interested for the first time in having a go at contesting, initially the CWops fortnightly Mini-CWT contest which we spent a couple of sessions rehearsing.
A big TU to CWops and Rob K6RB for all their efforts running the CW Academy.
There’s been a higher than usual level of activity on the AT-Sprint email list over the last few days as hints have emerged of a possible new offering of the popular MTR (Mountain Topper Radio) the latest of Steve Weber KD1JV’s radios that define the possibilities of ‘trail friendly’. To get a view of one in action check out this video from G4ISJ shot on a SOTA activation.
Steve KD1JV is the designer behind the PFR-3 and a number of other radios offered by Doug Hendricks’ QRP Kits along with the new Tri-bander Transceiver kit. But he also enjoys a passionate following for his high performance but tiny (Altoids tin size) radios in the ATS series where ATS stands for Appalachian Trail Sprint. These radios (especially the ATS-3B and the MTR) are prized by ham hikers and walkers who watch the ounces and milliamps. They are also an example of masterful interface design using small push buttons and minimal LED display. As Steve mentioned recently in a post reflecting his deep field operating experience “Little tiny rigs and knobs don’t work well together”.
During the buzz earlier today about whether he would offer more of the MTR kits (he will), Steve also announced his latest project “An 80/160 dual band rig with direct conversion receiver and a DDS/PLL hybrid VFO using all through hole parts.” (The ATS series made extensive use of microscopic SMD components and lots of the assistance Steve offers via the AT Sprint Yahoo group is concerned with discovering and rectifying makers’ errors assembling these devices.)
His website carries a pretty detailed three-page description of the design thinking behind the new rig which he’s calling the Super Deluxe Direct Conversion Transceiver. Tantalisingly he’s suggested it may be able to work at 500kHz. The new rig also features an “LCD frequency read out, built-in keyer and rotary tuning”.
He’s planning to offer only 50 kits at about US$75 at the end of November. Expect to see them sell out in two minutes! I suspect if he offered 200, they might last an hour or two.
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.
Just back from a few hours spent at the annual field day at Wyong hosted by the Central Coast Amateur Radio Club. This has to be the big day out for Australian radio amateurs. People came from near and far. It’s a good barometer of the health of the hobby and the local industry supporting it.
I was delighted to see – as the first exhibit as you enter – a full display of the Elecraft K-line presented by Gary VK4FD. Only thing missing was a KX3. Gary of course is an enthusiast, not an employee of Elecraft. A pretty good indicator of the passionate support the company enjoys.
The flea market became pretty busy as the morning progressed, but maybe not as many stalls as previous years. One stall that stood out for me at least was Stephen VK2SPS’s which included his offering of keys and bugs, surplus to his collection as he focuses on homegrown Australian manufactured keys. Eagle-eyed visitors will spot the McElroy bug (top, centre) and an interesting wooden based French military key towards bottom right.
Brilliant sunny weather, but not too hot to spend some time wandering about looking for a bargain or three. Also saw an impressive display of homebrew gear from members of the ARNSW Homebrew group.
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).
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!
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!
Last weekend I had a great time playing radio. Along with half a dozen other families and all our kids we went to spend the Easter weekend at the “mud brick mansion” at Bamarang on the Shoalhaven River, a few km west of Nowra on the south coast of New South Wales. Courtesy of the pod on my car I was able to take quite a few radio bits and pieces along.
We enjoyed perfect autumn weather while it rained back home in Sydney!
I even managed to build the neat little EFHW (End Fed Half Wave) Tuner designed by Stu, KI6J on a shady verandah. The kit had arrived a few days earlier and I made sure I had everything I needed to build it away from my attic/shack/workshop. In fact the weekend became a sort of trial for field day and a great way to identify the essentials. If there’s a lot of gear on hand an awful amount of time can be wasted deciding which bits to use and how.
I was inspired by reports about the EFHW tuner and the appeal of not having to worry about ground radials. What clinched it for me was a photo I saw on one of the (far too many) qrp email groups I try to follow showing a ham on a mountain side beneath his arching squid pole with the little tuner matching the hi-Z of the half-wave antenna to the 50 ohms expectations of the tiny transceiver which was probably an ATS3b.
So that was my mission for the weekend.
The tuner kit went together in a very short time. Before accepting my order Stu, KI6J sent me a powerpoint of the assembly instructions so I was sure I could handle the construction. The fiddliest bit was the tiny binocular ferrite core transformer for the bridge. Fortunately he provided enough wire in the kit for me to botch it the first time round and do it perfectly the second!
After a couple of leisurely hours mostly taken up with drilling holes in a tiny plastic box it was working on the test lash-up. The polyvaricon is delightfully sharp. You tune by dimming the LED – and then switch out the bridge to transmit.
I had a 10m (almost 33 feet) squid pole (aka Jackite or crappie pole) with a tiny pulley from a boating store attached to the top with cable ties. I used the guy ropes from my Buddipole setup to hold the pole up straight. It stayed up all weekend.
The half wavelength formula in feet is 477/freq in MHz, or just on 68 feet (20.7m) for the code end of 40m. The far end of this was held up – via a plastic button insulator – by a fishing line launched up into a tree using a half-filled plastic drink bottle. All too easy! The near end of the antenna simply terminates in a banana plug that connects to the little tuner. I also connected a short 5-6 foot counterpoise, which was essential.
I had a great time playing with the tuner and my new SDR-Cube pumping out a whole watt of RF, as well as the trusty little FT-817.
Now I have a clear idea of what’s required for an effective little kit of gear to take up a hill for relatively speedy SOTA style deployment. And maybe I’ll fill the water bottle for those trips.
If you’re interested in getting hold of one of these nifty little EFHW Tuner kits you should contact Stu KI6J at email@example.com. US$27 included shipping across the Pacific Ocean! Fast and very fair!
During a trip into the township to replenish supplies I found a fishing tackle shop with an Easter sale on, and bought a couple of handy Plano tackle boxes and some inexpensive 10m lengths of nylon coated stainless steel ‘leader line’ wire which I’m sure can be used for a handy weatherproof dipole. As long I don’t have to solder the stuff.