Happy Pi Day! Scottish Moonbounce in 1965, Eddystone Dials

Somehow this seems appropriate for Pi Day (3-14).  I guess it is because the antenna is circular.
Thanks to David GM4JJJ for sending this to us.  There is no audio. Kind of fun to watch the lads struggle with the big antenna while wearing coats and ties! 
 
David writes:
 

Hi Bill,

    Just watched the video of the progressive receiver and immediately noticed the old Eddystone drive and dial. 

    My first general coverage receiver was an Eddystone 840C in about 1969 I guess, so it brought back fond memories. 

    I also had (much later) an Eddystone 770R VHF receiver, which I used to listen to transatlantic 50MHz on during the sunspot peak a couple of cycles ago now. That was before we were allowed to transmit on 6m over here. 

    Incidentally if you saw the recent film "The Imitation Game" about Alan Turing, you might have spotted the 770R in it, which was actually a mistake as the receiver was not produced until after the war. 

Now something to break your heart, and mine actually:

    This old rig which was given to me sometime in the 70's by another ham, was stored the attic of my previous house now used by my brother, and a couple of years ago I had to clear the attic of the "junk" that I had left when I moved out. I didn't have any more room to store quite a lot of things and I made the decision to take a few things that I never thought I, or anyone else, would need. They went to landfill. :-(

    As you can probably see there is an Eddystone drive and dial driving a VFO which originally had insulation material around it for thermal stability. I think it may have been mixed or multiplied up to 144MHz judging by the scale on the dial. Looking back now I should have tried to save it, but I just felt at the time it would just probably lie in my new attic until I departed and then someone else would have to throw it out.

    I don't know exactly who made it, I was given it by Andy GM3IQL(SK), but I vaguely recall him telling me that it was made by Fraser Shepherd GM3EGW(SK) who I did not know as he died tragically young, but was a brilliant constructor. It could equally possibly have been made by Jimmy Priddy GM3CIG, and I could contact him as he is still around in his 80's now. At least I had the sense to take some photos.
  Now a couple of semi related video material that I put up on YouTube.

http://youtu.be/dqTLVLmz5ro

This is a (silent 8mm) film made in the 1965s about the first moonbounce attempts from Scotland and Jimmy CIG made the film. My Elmer Harry GM3FYB(SK) is in it. 

Another one this time 1965 field day!

http://youtu.be/UjYyaS1Fkao

    Bill, I really enjoy SolderSmoke podcasts etc, I am returning to ham radio after about a decade, got the bug again....

    The KX3 is in the shack, and I have the parts here now to build a QRP WSPR beacon by Hans Summers also.

    I like QRP, having previously worked with George GM3OXX back in the 70's when we went out portable with wideband FM QRP 10GHz (3cm) gear using Gunn diode oscillators. Just a few mW and we could work several hundred miles with small 2 foot dish antennas in the right conditions over water by super refraction. The receivers were just mixers, no active RF amplifiers in those days.

I think the best I did was 322km with my 10mW from Scotland to Wales on 10GHz. A couple of decades I built up a real SSB transverter with surplus MOSFETs for 10GHz and with greater power (250mW) and SSB bandwidths I could work non line of sight paths on that band from home. 

    I also like QRO for such things as 2m EME (moonbounce) and am in the course of replacing my old 8877 W6PO design 1500W amp for 144MHz with an Italian manufactured LDMOS 1kW amp that is a fraction of the size and weight, who would have imagined a single solid state device would be able to do that at a price amateurs could afford?

   Anyway enough of my ramblings. 

   Hope you don't mind me taking up so much of your time, I will let you get back to whatever you have on your workbench!

73

David Anderson GM4JJJ

 

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Final Integraton And On-Air Test of the LBS Transceiver (Video) (FB!)

Very nice.  A beautiful and educational project from Pete and Ben.   I have to start putting "tune switches" in my rigs and ammeters in the bias circuits of my finals. 

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Pete Juliano: Homebrewing With Transistors SINCE 1953!

I knew Pete had a lot of experience with transistors, but I didn't realize just how far back this experience reaches.  Pete writes, "The March 2015 issue of QST  had an article about a 1953 transistor transmitter project which was really advanced technology since the transistor was only invented about 5 years before that time...  About 1953 at the age of 11, I built my first solid state audio amplifier using the venerable CK722 from Raytheon. The transistor did look a bit strange in that cool blue cube shape with a red dot on the side to identify the collector. What a joy and surprise to me that it worked the first time power was applied...  It  was the CK722 that in large measure started me on a life’s work and engagement in a wonderful hobby. That CK722 path also led me to designing and building a QRP solid state version of the Collins KWM2 which I call the KWM-4."  I asked Pete why an 11 year-old kid in 1953 felt compelled to build a solid state audio amp.   The answer is very cool:  Pete's father had introduced him to crystal radios at age 8.  Pete wanted an amplifier for his crystal set, but his dad was worried about him building high voltage tube gear.  So that's how Pete got his VERY early start with transistors.

We are really lucky to have Pete Juliano sharing his vast tribal knowledge with us.


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N9IZ's Steam-Rollered Indy Mighty Mite (Video)

Not even the U.S. Postal Service's Anti-Crystal Steam Roller can stop an intrepid homebrewer.  OM N9IZ got his Mighty Mite working and produced a really nice video and blog post on the project.  You can just feel the enthusiasm:  On the blog he writes:   "Everything was assembled on a bread board for trial.  I must admit to being overjoyed when I saw the visual waveform on the PowerSDR panafall display of my Flex-5000A main shack radio.  So much so, that I ran through the house calling for my YL, KC9TAH.  She was in the shower and thought I’d cut off a finger or something while in the mad scientist lair.  Much to her dismay, it was only a nasty CW signal emanating from the Flex speaker.  She did humor me by going out to see the marvelous project before asking me what I was going to fix for lunch."  FB OM!   
  
Bill
 
I thought you might like to hear that another MMM has been brought into the fold.  You might remember that the crystal you sent me was steamrolled by the USPS.  Believe it or not, it works!  Not sure the frequency is exactly spot-on, but who cares...it works!  I enjoyed it very much and made a youtube video of the testing process.  I also took pictures and posted it all to my webpage.  Most of my other projects have been more QRO in nature so I'm treading in uncharted territory.  We'll see how far that goes, but right now I'm loving it.  I have my issue of QRP Quarterly and plan to follow along in constructing the LBS project.  All for now from Hoosierland.  Hope you enjoy the blog post on my webpage.  73 OM.

DE N9IZ

N9IZ Webpage

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Shep on Parasitics and Troubleshooting: "That way madness lies"

You guys really have to listen to this.  This is culturally important.   And it is a great follow-up to SolderSmoke 173.
 

In this 1965 radio broadcast, Jean Shepherd describes his teenage struggles with parasitics and other technical problems in his homebrew 160 meter transmitter.

He describes the sound of parasitics on a signal, saying that they sound as if the signal is being attacked by "debauched erotic locusts."

He really nails it in describing the scornful, dismissive tone that many hams use in telling their fellow radio amateur that there are problems with his signal. ( I have recently been on the receiving end of this kind of treatment.)

He observes that no one is more worried, "than a man who has built something and can't get it to work." Indeed.

During a date with a girl from his high school, he is so obviously pre-occupied with his transmitter trouble that she tells him that something is wrong with him and that his mother "should take him to a doctor."

And he describes the joy that comes when you figure out the problem and get the thing to work.

The REALLY good stuff begins at about the 25 minute point.

http://ia310115.us.archive.org/2/items/JeanShepherd1965Pt1/1965_01_29_Ham_Radio.mp3

Shep was quoting from King Lear: "O, that way madness lies; let me shun that; No more of that."  In other words: "BASTA!"  That is what I have said about my 40 meter troubles.  My BITX 20/40 is now a BITX 20. 

EXCELSIOR!



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The Original BITX 20 -- Designed at 35,000 Feet in 6 hours, Built in India in 3 Days

 I came across what appears to be an early version of Farhan's description of the design and initial construction of the BITX 20  (see below); this version has some interesting information on the origins of this important rig.  The picture below shows the designer himself working on that first BITX20.  It is from a CNN video.  I know Farhan is sick of seeing this old video, so I present here only the shot of the designer's hands at work on the original transceiver.

 

Some thoughts from the designer, Ashhar Farhan, VU2ESE: 

    This transceiver was designed during a six hour flight from Europe with paper, pencil and the basic calculator built into my cell phone. It was soldered in three sittings over three days. Very little went wrong during the construction. It was one of those easy designs. The only mistake that I made during construction was that I soldered one of transistors in reverse. The design worked as ‘advertised’. I guess that extensively using feed back amplifiers provides designers with greater repeatability. Also, I realized, a little late in life though, that detailed forethought and ‘mental’ home-brewing is important for a clean design.
    The linear chain was initially unstable. It tended to oscillate in the 14MHz band as well as around 500 KHz. I traced the 14MHz oscillations to a choke that I was using at the output of the balanced modulator. It has been removed. The 500 KHz oscillations were because of excessive gain in the driver and pre-driver stages. From 5 ohms, the emitter degeneration has been increased to 10 ohms and better bypassing on the power rail has eliminated the oscillations.The receiver is as hot as I need it to be on 20 meters. Signals from USA, Europe, South Africa and of course India were heard with clarity reminiscent of a clean Direct-conversion receiver on the first evening. The transmitter is powerful enough for local rag chew and it is a modest challenge for DX. VU2PEP has an excellent two element beam at 20 meters at about 40 feet height. DX is easy for OM Paddy who uses the rig regularly. We netted LA2FKA within the first 20 minutes of firing up the rig.
    No, I don't offer PCBs. I don't repair rigs. I don't offer kits. I might do a PCB for this rig (I hate PCBs, they hamper experimentation).
    This transceiver is dedicated to the memory of OM Juggie, SK (VU2JH) who was a great organizer of India hams, he wrote technical articles in Electronics For You magazine about amateur radio, spurring many to take on ham radio as a hobby. He organized the Millennium Ham Meet in the year 2000. He was always searching for a good and simple homebrew SSB transceiver. He died young. He gave me my first morse key.

Jagdish, VU2JH

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SolderSmoke Podcast 173: Pete's LBS Triumph and Bill's Tale of QRO Woe

SolderSmoke Podcast #173 is available:

http://soldersmoke.com/soldersmoke173.mp3

7 March 2015

Bench Report:   Pete's Progress on the Let's Build Something Rig:
http://www.jessystems.com/LBS_Detail.html
Ben's cool case for his LBS rig
Bill's Tale of Woe:  QRO troubles with the BITX 40
    -- QRO amplifier taking off on 40 (but not 17)
    -- Criticism and public humiliation on 40
    -- Troubleshooting
    -- Suggestions from Allison
    -- A sad realization about my VFO frequency selection
    -- Exorcism needed
    -- Pete suggests a digital solution
    -- Wow, my 'scope has an FFT!  Almost a spectrum analyzer!
    -- Some thoughts on trouble shooting
    -- On the meaning of "BASTA!"
The Spring 2015 Issue of Hot Iron http://www.walfords.net
More on Pete's KX3
Encouraging other hams to build

 

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