HB2HB! KW4KD and N2CQR (video)

A couple weeks ago I ran into Jim KW4KD on 40 meter SSB.  Jim is in Chattanooga, Tennessee.  He was running a modern "black box" rig, but he mentioned that he had on the shelf two complete homebrew stations, one of which was for 40 meter SSB.  He hadn't used this gear in 40 years.  I encouraged him to blow the dust off and get it on the air.  Yesterday, Jim did just that.   We met up on 40, first at 1730 local (my time) and again at 1930.   Excellent!  Another HB2HB contact.  Check out the video (above).   Thanks Jim.

If you run into someone who mentions having some old homebrew gear, encourage them to blow the dust off and get it on the air.

Jim's SSB rig:

The Invention of the Reflectometer: Naval Research Lab Report #3538

Dennis Klipa N8ERF has been doing great work exploring the technical intricacies of the humble SWR meter (and believe me, there are intricacies).   He's also been looking at the history of this invention. 

This summer, Dennis and I came across the April 1964 issue of Popular Electronics.  On pages 74 and 75 of that issue we found a clue that seemed to point to the origins of the device:  the article referred to Naval Research Lab Report #3538 by O. Norgorden,  published on September 15, 1949.  This may be the paper that led to the widespread use of SWR meters by radio amateurs.

Surprisingly, this important paper was not to be found on the internet.  Exhibiting an admirable dedication to the preservation of an important element of the radio art, Dennis wrote to Naval Research Lab and purchased from them a copy of the report.   Unfortunately, the version Dennis got had been copied and recopied so many times that it was hard to read.  So he went the extra mile and re-typed it. 

With his permission, I am giving this article its internet debut by posting it here:

http://soldersmoke.com/SWR N8ERF.pdf

Three cheers for Dennis Klipa for unearthing this important piece of radio history.

From the Wizard of Wimbledon: Matchbox Junkbox Rig

Dear Bill

I hope that life’s treating you kindly over the left side of the pond. Your latest podcast really resonated with me as I’m hugely fond of junk box projects on a rainy afternoon. Fortunately Her Majesty’s weather men are generous...

Spy gadgets have long been a fascination of mine, particularly those disguised as harmless everyday objects. I remembered a Soldersmoke blog post a few months back showing a radio hidden inside a book. That got me thinking… then one rainy afternoon I stumbled across a half-used box of matches – surely an ideal enclosure for a covert spy transmitter!

Objectives:

1.    The matchbox should remain fully functional and pass casual inspection
2.    Transmitter, Morse key and battery should be hidden within the box
3.    All parts should be cobbled-together from what I can find around the house
4.    To build using “Manhattan style” construction for the first time

The transmitter borrows heavily from the Pixie 2 circuit and is based around two PN2222A transistors: the first forms a Colpitts oscillator for 7030kHz (plus/minus a smidgen of capacitor trim), the second acts as a modest Class C power amplifier (approximately 170mW out) – keying occurs here, to minimise chirp, before feeding a simple low-pass filter. 

Discrete contacts set in the cardboard allow Morse to be keyed with my grandmother’s old sewing thimble – not only is this beautifully stealthy but it’s remarkably ergonomic too!

The transmitter can be easily teamed with an external receiver, selectable via a double-pole-double-throw switch. The switch simultaneously disconnects the battery, eliminating the audible whistle from the constantly-running oscillator.

This was my first experiment with “Manhattan style” construction and I can see why you swear by it. Even though I sketched the circuit’s layout before I started, I still found myself occasionally popping-off a square with a blade so as to optimise the tight packaging; Manhattan made this trivial, and fault-finding would have been easy with all connections on one side…

But remarkably the transmitter worked first time! Bench testing by calling CQ whilst monitoring the Reverse Beacon Network demonstrated that its tiny signal could be picked up as far away as northern France when driving my resonant end-fed antenna!

Ever since I discovered the magic of QSL cards I have always wanted to send one showing a hand-drawn diagram of my transmitter; perhaps I’ll now have a chance!

Please keep up the great work: you, Pete and the global brotherhood never cease to throw up new tricks for me to try. It’s a shame that this is perhaps one radio which I’d be best advised to not try to carry through airport security when my ever-patient girlfriend grants me permission for a holiday-time QRP operation...

73

Jonathan

M0JGH

--------------------------------

Earlier post about Jonathan: http://soldersmoke.blogspot.com/search?q=M0JGH

Update on Farhan's BITX 40 Module

It is truly a thing of beauty:  http://www.hfsigs.com/   

The boards come assembled (as seen above).  You can then add peripherals and modify away.  It is "hackable."

Hackable

The BITX40 will inspire you to experiment. Modify it, mount it, tweak it, change it.
The PCB uses all analog large sized SMD components that are laid out on an easy to understand manner on a double sided board with broad tracks. This can be your main module around which you can start experimenting. There are jump-points from where you can add more modules like the DDS, more bands, better audio amplifier, etc. Imagination is your limit. You can separately increase the power amplifier's supply voltage to 25 volts to be more than 20 watts of power : You will have to add a better heat sink. The mods are on the way!
The board can be installed inside any box that you like. Make your own station rigs, man-packs, trail radios or mount it in a cigar box and leave it on your bedside table. The tuning capacitor has been replaced by a varactor tuning so you can place the tuning knob anywhere as it only carries a DC voltage.

Farhan writes:

For the last few months we have been working bringing low cost, tested SSB boards. Finally they are here. Priced at Rs.2200 At the moment, they are available only in India until we sort out an inexpensive way to post them to other countries. Visit www.hfsigs.com and pick up one!

The BITX40v3 is a complete 7 MHz SSB transceiver on a board that puts out 5 watts of clean audio and it has a very crisp, all analog receiver. It is based on the popular BITX circuit. It is a high quality double side, PTH PCBs with machine assembled SMD components, hand wound coils and each of them is individually tested. All the connectors and wires needed are included in the kit.

JH8SST/7's Build of Pete's Simpleceiver

Beautiful. 

Makes me want to put S-meters in my rigs.

More on Pete's design here:

http://n6qw.blogspot.com/2015/09/simpleceiver-40m-ssbcw-receiver-and.html

In De Ether (Short Belgian documentary about ham radio)

In De Ether (English Subtitles) from Ivo Maes on Vimeo.

From the DSB-SSB Pier In Melbourne, Australia: SolderSmoke Book Reviewed by VK3YE

It is a real honor to have my book reviewed by DSB guru Peter Parker VK3YE, and to have him do the review from the iconic "DSB-SSB" pier in Melbourne, Australia.  Check out the video (above). Thanks Peter.