Homebrew tx for $50 ??

AB8RO has posted to QRZ.com a summary of a magazine proposal. I don't subscribe to the League, so I missed it, but it sounds like the AM community, specifically the MOSFET Mob, could have some fun taking the crown.

You are to design and build a rig. Deadline for submissions is Aug 1, 2007. One of the most interesting parts was that they wanted the rig to work in both the cw and voice segments of 40 meters. You can use AM,SSB, or DSB for the voice modulation. The rig must cost less than $50 in new parts to build. You don't have to include power supply, microphone, headphones or speaker in that $50. I suspect AM might be easiest to do, but, not quite so useful as SSB/DSB. In my mind, DSB is the right compromise here. A VFO might be the cheapest way to span voice/cw segments, but, a stable vfo that covers that range is not so easy to build for the beginner, and, the only test equipment you are allowed to assume the builder has is a multimeter. A switched crystal VXO, would be stable and easy for the beginner, but, for direct conversion would require spending a chunk of budget on two ham band frequency crystals as you're not going to bend one down that far. Maybe there's a cheap source for those, but, I don't know where to get them cheap. An interesting alternative might be to mix 3.579 with 3.579 or 3.68. The first combo gets you in the novice segment and the second into the general voice segment. With a 3.579 IF you could employ an inexpensive variable bandwith crystal filter ala the Elecraft KX1 since the crystals themselves cost pennies. By using ceramic resonators instead of crystals in the VXO you can trade a bit of stability for some additional span. It has to have at least five watts out as well. I plan to try and meet the challenge for myself. That is, I'll put a rig together with some of these ideas. I'm a bit of a hack when it comes to building though so it's unlikely I'll bother to submit anything. Half of the stuff I build I don't even have a full schematic for, it's figured out on the breadboard.

Daryl's post and the discussion are at:

http://www.qrz.com/ib-bin/ikonboard.cgi?s=41b47fccd570bc85a53b86c530d85bfc;act=ST;f=7;t=128031