AMECO AC-1 CHASSIS MODIFIED FOR RX/TX OPERATION 6V6/6SK7 TRANSMITTER/REGEN RADIO

Description

This is a good project for someone that has a technical background and likes to experiment. Some years ago I acquired a complete Ameco AC-1 clone kit and decided to add a few parts and use the chassis for a regen receiver/6V6 transmitter combination. I worked with it for a time, and then set the project aside and just never got back to perfecting it.
So it has seen very little use, and, again, most all the parts are new, with the exception of the 6SK7 regen tube and a few other minor components.
I had it powered up at the time of listing and was copying WWV and a few shortwave stations. The receiver requires high impedance headphones (2 to 4k inductive type). Or, since the audio out has capacitor coupling, you could also use a hi-z piezo headset or external audio speaker amp.
The original AC-1 was crystal controlled, but my intent was to add a VFO. So it is a single tube 6V6 vfo with the standard Pi-network tank circuit for the transmitter. The VFO does function, but I was still working on getting the right number of turns on the plug-in coils for the 160, 80 and maybe even 40 meter band.
Problem is, a direct frequency VFO begins to get a little unstable, with an increasing saw tooth tone if you try to push them much above 80 meters. So when you get the VFO coils figured out, probably best to avoid 40 meters, since you may be lucky to even get a 7 or 8 out of a possible 9 tone quality at the 7 mhz frequency.
Worst case scenario you can simply use the VFO coil socket and change the circuit back to crystal only operation as originally intended. In that case you’ll still have the regen receiver, plus the 6V6 transmitter. For crystal control you can then use the vfo variable cap for a series crystal vxo control.
The original AC-1 schematics are an easy find online and fairly simple to work with. I’ll even throw in the few parts you’ll need to make the back to crystal conversion if that’s what you decide to do. The original AC-1's were plagued with chirp problems, but there's a 50 cent fix for that, which will allow you to use even the QRP HC49/U crystals that are cheap, plentiful and easy to find on eBay.
The power transformer has a 250 volt winding with center tap, so I have it wired with a 4x 1N4007 bridge rectifier circuit, delivering a dc voltage of around 300v dc, more or less. This will easily give you 7 to 10 watts RF out with the 6V6 oscillator/transmitter. There’s a send/receive switch on the front panel to mute the receiver when in transmit mode.
My artwork is not great but I’ll sketch a rough schematic from memory, as well as a diagram of all control functions. The schematic may not be 100% accurate, but it will be close enough for most anyone having some basic technical experience. This old analog technology is just not that complicated to work with.
So I’ll provide about 4 to 5 plug-in coils that I was working with, plus a couple of QRP crystals for 80 and 40 meters, just in case you want to convert the chassis back to crystal operation. Many possibilities here for somebody that likes to tinker and experiment.
Obviously, when plugged in to 117v ac this chassis becomes quite lethal to work with for someone that does not have experience in handling high voltage circuitry. Please DO NOT purchase this item if you are not familiar with the safety hazards involved when working around high voltage.
Sold strictly as is, no warranty implied, except that it will power on and function within the limits described. There’s yet some work to be done in order to make this little RX/TX combo fully functional for on air use. Within reason I’m happy to answer your questions after purchase. Over the years I’ve constructed at least two or three dozen of these one tube oscillator transmitters, and have been a technician and ham radio operator for more than five decades. Like most ham’s, always willing to share acquired knowledge.
Shipping to the United States only……Best of luck! 73’s, KW7T