I know Chas published his little valve transmitter in Radiophile some years ago because I subscribed at the time and saw it. But since then I gave the magazines away to a budding vintage radio enthusiast.
So could anyone send me a scan of Chas' article please?
Than you.
Regards,
Ian, G4JQT
There is a 6 page article in Issue 116 Summer 2009 by Tony Thompson about a PANTRY transmitter, is that the one you were looking for?
I assume that this is still copyright? I have the article but don't want to risk upsetting Chas, I believe he has back issues available from *removed*
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Please note the EDIT comment in the previous post.
Thanks
I don't want to open a copyright can of worms. I assumed this would be similar to downloading music when one has already paid for the LP or CD, etc. (which I understand is not infringing copyright, or stealing music, etc. provided it is for your personal use only), and someone could just email me a copy.
I did subscribe to the Radiophile for a number of years, but think I gave most of them away. I thought I kept that one, but it seems not.
The article I'm thinking of may be by Tony Thompson, but I thought Chas published his design in the magazine, or maybe I saw it once in his book.
I've been playing with a valve design recently which was rather poor, and thought a look through some of the 'classic' valve pantry transmitters might be useful.
Regards,
Ian
So you know Chas, Radiophile, I got my knuckles rapped for nought even though the info was "trade" not private.
However to help you further, there was a construction competition article for a medium and long wave pantry transmitter in the Spring 2004 issue #97 if that was the one you were thinking of.
Perhaps you had better pm me for any further help/info and I can see what I can do.
A transistor, a ECH81 or a SA612 will do it simply.
I have one that uses a ceramic resonator in the 400KHz region and a loop coupled well to Ever Ready Personal B at twice the frequency, which is as about the most deaf AM radio I have apart from the near identical Marconi and the slightly different MW/LW Marconi replacement model.
Rod Pentode 1j18b
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One transistor and resonator (or crystal). You can use fundamental or a harmonic. Use a tuned loop on collector.
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Thanks for the replies.
I designed the MiniMod and various other (much higher power) MW solid state transmitters, but just for fun thought a simple valve low-power 'pantry tx' would be an interesting project. Iit doesn't seem worth trying to reinvent what others have already done.
Ian
I have a bag of about 60 similar 500kHz resonators. So if 1MHz is quiet in your area and you want to try this out PM me. FOC + 2nd class postage.
Al
Could let you have a scan of Peter Lankshear's Mate Xmitter Ian. It was published in Australia Today ? in the mid 70's. As a friend I know there are no copyright issues, he wont mind a jot and the Mag is long gone.
I made it and with some mods, mainly in construction it worked well for years, never turned it off; it had a push button FM receiver hooked to it.
Gary
(26-10-2016, 08:59 AM)Radio Fixer Wrote: [ -> ]Could let you have a scan of Peter Lankshear's Mate Xmitter Ian. It was published in Australia Today ? in the mid 70's. As a friend I know there are no copyright issues, he wont mind a jot and the Mag is long gone.
I made it and with some mods, mainly in construction it worked well for years, never turned it off; it had a push button FM receiver hooked to it.
Gary
Hi Garry,
Thanks, but I've found that one online in 'Discovering Vintange Radio' (no date) and repeated in Aug/Sep 92 Radio Bygones, also online. (It's always good to see old copies of magazine freely available on the internet to anyone who's interested, and more and more magazines covering all subjects are doing this now.)
I also found the various AM valve circuits posted by Fred Nachbaur and the EH90 Pantry Tx by Trevor Goodenough.
I've been spurred on in this direction when a friend brought an ECH35 circuit that almost worked. But for the tapped oscillator inductor he'd used was one of the small coils used in the MiniMod. Fine in theory, but I think the cathode current going through the short tapped section just burnt it out!
It would be easy enough just to copy (and modify for better audio) a Codar AT5, but my point is to keep the design simple to one or two valves, giving enough modulation from just the h/p socket of an MP3-player (or similar), and generate a well-modulated RF output power only a few hundred mW at most. Hence my attempt to collect various designs to see what 'theme' emerges. I'm sure Chas' design will add significantly to my gathering data...
Ian