A few days back I slapped together an superhet, it kind of works, certainly nothing to rave home about that is for sure. A few take outs from it, using MMICs as IF amps is not a clever option as you really cannot control the gain all that easily. And the other thing is audio. You really gotta make sure you use an audio amp with sufficient enough power rating to drive a speaker.
After playing around with things, I did notice that I had some rather obvious distortion. After changing out the audio amp for something sturdier and testing the audio stages by themselves, I came to the conclusion that the distortion was coming from the IF amps. I will see if i can tame the gain in them somewhat and see if i can get this working better.
I am still not sure about the audio sound, the SSB filter is somewhat thin and the audio AGC is really not AGCing. I am not sure what is going on there. But I have an AGC ic here on a board that i might try and see if that works better than the discrete version that I built.
I configured the superhet with both CW and SSB IF filters. Not sure how good my filters really are, but once i sort out the distortion, it should be able to see how the filters perform.
