I want to build a simple crystal driven, AM receiver. I searched the web, but found only crystal driven transmitters and no "simple" crystal driven receivers. Can anyone tell me how to build a simple crystal driven receiver cct? I perfer a cct without inductors.
Direct conversion CW (morse code) receivers are indeed popular and easy and often done with crystals, but they do not make good AM receivers. It's not that they're completely unusable but the beating of the receiver crystal with the transmitter's carrier is really irritating, and the AVC features of regular superhet AM receivers are not present either. (Some direct conversion receivers do have their own way of doing AVC but it doesn't work well for AM. It's mainly to prevent blowing the ears off the poor guy listening to a weak CW signal when an adjacent powerhouse keys up.)
Superhet crystal-controlled receivers were popular for fixed-frequency AM use (think CB transceivers back when each was filled with 23*2=46 crystals), but the crystal frequency for receive is different than the one for transmit by the IF frequency.
There's been some discussion here about fixed-frequency AM receivers using a crystal filter not in the IF, but basically just hooked to the antenna.
That's a tall order! You can build a transmitter with 2 transistors, but it's not so easy to build a receiver: receivers require a lot of gain - which takes several stages of amplification; also, if you want crystal control, you'll need a transistor for the local oscillator.
You could make a high-gain, super-regenerative detector with a single transistor, but that usually involves inductors. I've never seen a regen. circuit using a crystal resonator insteads of an LC tank. That would be novel.
Would you consider integrated circuits? Realistically, I think this is the only way to do it without inductors. How about an NE602 / SA602 front-end (rf amp, crystal controlled LO, mixer) ?
What's your objection to using inductors anyway? You won't get far without them.
Do you mean a receiver with a crystal oscillator? There are lots of those around, they are popular with radio amateurs. They are usually tunable over a small range by 'pulling' the crystal with a variable capcitor.
Leon Heller, G1HSM
The selection certainly isn't as broad as with capacitor, but I've found that you're much more likely to end up winding your own inductors for switching power supply designs than for RF designs (where you can get adjustable inductors or just squish/pull apart air cores). And with switchers for cheap and sleazy prototyping you can wind them quickly solenoidal style and spray a little flux around the room before you finalize component values and wind a nice toroid or pot core or whatever...