Showing posts with label DIY Radio. Show all posts
Showing posts with label DIY Radio. Show all posts

TNT Uncovered - Flea-Power (QRP) Telegraph Transmitter in the Pilot Radio's "Radio Design" magazine, 1930's

Pilot Radio And Tube Corporation, trade mark

I found this article in the Lloyds Dipsy Dumpster - site, where you can find a lot of rare vintage radio articles, manuals and data sheets.

It is remarkable, that "Pilot Radio & Tube Corporation", well known as a manufacturer of the great Super-Wasp receivers, was a publisher of a Ham-Radio literature, handbooks and magazines, as well as many of early radio manufacturing companies. As for me, I like that sort of advertising much more, than modern spam in my mailbox and if it would be possible, it should be a nice choice to make this QRP transmitter using a native Pilot's parts only.

Anyway, when I've read this article, one interesting fact has drawn my attention - I can recognize the TNT when I see a TNT design, but in the text this transmitter has been described as a TPTG.. Moreover, there is a grid capacitor on the assembles view, but with a opposite description below: "condenser is not needed". So, in the article we can see that mysterious moment, when as the chrysalis becomes the butterfly, TPTG transmitter was transformed into a trendy TNT.

6N7 Tube QRP Power Amplifier - One Rainy Day DIY Project

QRP 6N7 Tube Amplifier
Once upon a time I'd decided to join a Big Guns Gang and made a Super-Duper Powerful Vacuum Tube QRP amplifier for my 800mW QRPP homebrew telegraph vacuum tube transceiver "3T" (I promise to write a separate article or two about this three tube transceiver project later). It was not an easy decision to me because for that legendary time I'd almost a year used the QRPP power of less than a watt, but there was a rainy spring day, I've called CQ again and again without any takers and, at very last, somebody took over my only rock bound frequency. "That's all" - I said - "Enough!" ..and turned on my Soldering Iron.
Let me describe the scheme. Grounded-Grid design has been chosen because it is simple, easy to matching to coaxial impedance, provides the necessary level of amplification and typically requires no neutralization. After several experiments with triodes and double triodes I'd chose a 6N7S (6H7C) valve - Russian glass shaped version of well known 6N7 vacuum tube. I know that there was a 6N7G and 6N7GT American glass tubes, but as I heard these ones was not as common as metal 6N7.

Building A Vintage 1929 Style Transmitter - Best HOWTO

Yes, Best HOWTO Ever, but not mine - hats off to Steve VE7SL. I've found this great article reading the Glowbugs mail list and I have to post it here because this article is a pure gem. Even if you never did it before, after the reading of that article you can to, you have to make your first TNT or Hartley transmitter and trust me - it is only first steps into the amazing world of glowing history!


"After some research into the 1929 transmitter style, it became apparent that most amateurs of the period were using either a Tuned-Plate-Tuned-Grid (TPTG), a Hartley oscillator or a Tuned-Not-Tuned (TNT) design. I can well imagine the countless late night 160m AM QSO's of the day discussing and arguing the virtues of each amateur's chosen design. Eventually I decided on the TNT, a simpler off-shoot of the TPTG design."

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Junkyard Warz Novelty Transmitter by W9QZ

Several month ago I found a great, probably most artistic Glowbugs Radio homebrewer in the WEB - Rick Weber, W9QZ. I've been very impressed, downloaded some beautiful photos of those stylish Rick's HAM-Radio artefacts and, naturally, forget to check this page again - it was my mistake. Take this:

JunkYard D.I.Y. Transmitter

"Junkyard Warz Novelty Project. This is a working Hartley transmitter I built with all non-radio components except for one 027 vacuum tube."
Visit W9QZ Vintage Gears and enjoy the fire of these FireBottles (not only fire - you can find some bottles turned  into HF insulators in the Lab of Great Steampunk Wizard, W9QZ)
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Second Life of Dead MFM Hard Drives - Iambic Paddle

Homebrew Iambic Paddle Just finished my first in life "Instructable" at the D.I.Y. host site instructables. It is short sketch about Iambic Paddle which has been made using a spare parts from the dead MFM HDD drive. I got a lot of fun posting to that site, and I think that it should be good idea to post more detailed article here. Frankly, this homebrew project is not a Pure Glowing Bug, but I'm not so puristic today.
Well, let me explain - why I decided to use HDD heads as a levers in this Iambic Paddle Project. For many years I've collected computer spare parts for no reason, just because I have a big, nearly endless Junk Box and it was impossible to me to throw such high-tech toys in the trash. But one morning I found that my Junk Box is full and The Time of Trash Bags has come. It was a hard work, but under the tons of debris I found the treasure - my first homemade Z80 Sinclair Spectrum and five old 5 inch MFM hard drives from my second computer.
As you remember, these drives was a big rounded shaped boxes, ideal as a chassis for any homemade electronic projects, tube glowbugs as well as solid state stuff. Another interesting things - powerful electromotor and magnetic cylinders itself, thick shiny discs which are so usable as a dial or scale part, looked much better than a CD in this role. And last but not least - yes, precision bearings on the easy to mount axis in magnetic head's block. What a beautiful hardware! When I opened and totally disassembled these hard drives, I realized that I literally had a very new telegraph key, usual one lever, dual lever iambic paddle or even straight key - not so important, it is easy to make any kind of telegraph manipulator using these nice spare parts. Watch this video demonstrating a working Iambic Paddle and take a look at step by step constructing process here:

Big Nick and the Cydecos - Glowbugs Radio Hide-And-Seek

KC9KEP's ARRL 1941 7-Tube Superheterodyne Homebrew Radio Today I decided to become (at very last) a real blogger and to invite some celebrities as a trendy stuff. But as it turned out, neither Madonna nor Britney Spears did not make the tube radios, Arnold Schwarzenegger is possible and would do, but too busy at work, and Michael Jackson .. Okay, let's not about sad - the result of my quest was a brilliant success:

Free Radio Nova

Free Radio Nova Transmitter
Long Live Glorious D-STAR, DRM, SDR, VoIP, DSP, and their Amazing SMT! 

Long Live Modern HAM-Radio, FairLand of Bells, Whistless and other Adaptive Filters!

Heil to the Morse Decoder Software!
Voice Keyer is Our Savior! Huray! eQSL!

* * *
But now.. [drums] But now...
* * *
Yes, it is Pirate Radio and yes, We are The HAMs,  We are proud to be not a hobby, but Emergency Service. I confirm. Don't shoot me, please. I've just read a short message about this station on the Irish Paul's blog and I recognized The Radio when I met. Even without LCD.
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Evergreen Exciter for the Special Night

Magic Eye Transmitter
Several days ago I listened to the completely empty ten meters band. There was a lot of noises, quiet CB chewing and nothing else.
Suddenly I heard a slow, quiet, but very clear telegraph code, resembling W1AW QST. I have not heard the beginning, but wrote all heard:

Simplified Amplification

UB5UN & UT5AA SSB Handbook
There was a Book Of The Books in early 1970's - "Amateur Radio SSB Equipment" by S. Bunimovich (UB5UN) and L. Yailenko (UT5AA). Funny, but this book can be found in a common pirate's shack as well as in an Extra-class (1-st xUSSR category) HAM one. Yes, xUSSR pirates used AM only (mainly?), but this book was a great source of knowledge about tubes, transmitting equipment etc for everyone who been proud to heat The Ether.
There is a huge pile of a very complex things that described so comprehensible in this book, such as Phase Shift SSB Modulators, complete Transmitters, SSB Receiver's features, Dynamic Biasing and much more, but it is too hard work for me to translate all of those great articles and I decided to start with exposition of pair of a Ground Grid Linear Amplifiers - so simple, not so powerful, but namely these amplifiers was most popular in 1970's. Thought, every xUSSR HAM made one of these amplifiers and used one with a great success.
As for me, I did :)

Straight Key Night M.O.P.A. Transmitter

SKN Operating Position
After reading a lot of ancient QSTs, ARRL and Jones Handbooks plus e-mail conversations with my friend, Louis VE3AWA about American depression-era style rig design, I decided to build a classic breadboard transmitter in time for Straight Key Night.

Well, breadboard MOPA seemed like a very interesting idea, it was absolutely unusual for me - I never used wooden chassis (breadboard) without any metal shielding before. Second problem - I'd started this project too late, for only one week before the SKN.
To my surprise, I got my firefly finished and fired-up during Straight Key Night! Without any success - there was no SKN participants over here. But what done is done and I was so glad to hear many "loud and clear" signal reports and heartwarming words from EU CW stations. Maybe next SKN, VE and W stations will make a sked to work UU1CC.