VK2RH ham radio

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  • 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 to create a very cute looking valve wearing blue shorts.

    Hand made triode

    F2FO, radioamateur depuis 1959, montre ici les différentes étapes de la construction d’une lampe triode réalisée par ses soins. Cette lampe a permis d’établir des liaisons avec d’autres radioamateurs situés sur 4 continents.
    Si vous souhaitez en savoir plus, visitez son site web personnel : http://paillard.claude.free.fr

    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.

    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.

  • 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.

    Crystals go to War, 1943 – A story in pictures of the preparation and manufacture of quartz crystals for radio communication

    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.

    “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…

    You can read more of the detailed earlier history of the evolution of the US quartz crystal industry at https://ieee-uffc.org/about-us/history/uffc-s-history/a-history-of-the-quartz-crystal-industry-in-the-usa. It tracks how early manufacturers developed techniques for cutting and grinding the natural quartz for the most accurate results.

    Frequency measurements were made by determining the difference between the frequency of the test blank and that of some reference frequency such as a secondary frequency standard consisting of a one MHz crystal unit controlling a frequency generator which developed a set of radio frequencies having integral multiples of 10 kHz. Measurement of the difference frequency, detected by a radio receiver, was a major problem which was solved in various ways. One of the early manufacturers, E. L. Shideler, used the family piano as an interpolation oscillator. More affluent manufacturers could procure an excellent analog frequency meter from General Radio Co. and within a short time David Packard and William Hewlett developed the HP-200 audio oscillator which not only met a need in the quartz crystal industry but also launched the Hewlett-Packard Corporation.

    A History of the Quartz Crystal Industry in the USA
    Proceedings of the 35th Annual Frequency Control Symposium, pp. 3-12, 1981
    Virgil E. Bottom

  • Reading in your head – the long path to morse code bliss

    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.

  • Lightweight portable VHF antennas

    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 components of a DK7ZB lightweight 6 element yagi suitable for SOTA or any portable operation

    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.

  • SOTA launch in VK2

    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.

  • CW Academy FB

    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.

  • New KD1JV ultralight rig for 80/160

    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’s popular MTR ‘a very small, very efficient, two band rig’ is set for another future offering

    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.

  • 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.

    UPDATE: The YouTube video has been blocked by the BBC on copyright grounds. Another version with slightly dodgy audio may be available here.

    ‘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.

    This is a very well organised and presented documentary.

  • Solar news

    Under the title “Earth braces for biggest space storm in five years” ABC Australia’s online news reports on the last 24 hours of solar activity.

    A NOAA space scientist is quoted “Space weather has gotten very interesting over the past 24 hours”.

    Further detail as usual from http://www.spaceweather.com and http://www.swpc.noaa.gov/today.html.

    UPDATE: 24 hours later – “Space storm fizzle“!

  • Big Day Out at Wyong

    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.

  • At last the wait is over

    The final hours before the actual opening of orders for the new Elecraft KX3 saw a mix of bizarre behaviours on the KX3 email list from impatient petulance and other weirdly strange attention seeking. They were a tiny minority in a sea of patient fans happy with the frequent updates from the Elecraft team. In the end when they started taking orders it wasn’t really a surprise. And Elecraft met their December deadline and kept some holiday suspense to the end.

  • Waiting list update

    On Halloween Steve Weber KD1JV has announced to the AT-Sprint Yahoogroup he’s considering planning to take orders online for the ATS-4B at 11:11:11 AM, EDT on the 11th November, 2011. Clearly a time and date not to be forgotten. Shipping would follow close behind then. One exciting aspect of this latest ATS-4B version is the planned integrated CW/PSK decoder on a daughter board, planned for a January release.

    And the other hotly awaited item for the QRP and HFpack crew, the new Elecraft KX3 is now likely not to start shipping until the new year, 2012 I presume. An apparently hastily written update indicates “KX3 estimated ordering date (Winter 2001) and shipping date (January)”.

    UPDATE: We’re getting closer. On 2 November this has been updated to “KX3 estimated ordering date (Nov/Dec 2011) and shipping date (Late January)” [my emphasis].

    I’m dreaming of an expensive Christmas.