26-10-2016, 09:53 AM
(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
