I am interested in some easy, lower cost and reasonably useful schematic w/instructions for tube-type super het shortwave and ham receivers that the average electronic tech could build . Any ideas for the best sources ?

Ray

Check here.

http://antiqueradios.com/forums/viewforum.php?f=12

Norm

:I am interested in some easy, lower cost and reasonably useful schematic w/instructions for tube-type super het shortwave and ham receivers that the average electronic tech could build . Any ideas for the best sources ?

http://www.users.bigpond.com/cool386/12at7/12at7.html

I like this one. I built the superregenerative FM, though I didn't make my RF amplifier also perform as an audio reflexer. I decided to just build a conventional audio amplifier. The receiver receives most stations well. Some weaker ones have a bit of noise. The receiver can be greatly improved by adding an active tuned RF amplifier. However, such an amplifier must be shielded very well, and the superregenerative detector must also be shielded very well. If they are not, they will feed back on eachother. You will find lots of dead spots on the dial. That said, shield each stage and its components well if multiple stages are to be built. A twin gang tuning condenser becomes necessary for synchornization, and each gang must be well shielded from the next (each being enclosed in a box would help).

If you just build the circuit as he shows it, though, you won't need much shielding. Shield from the audio amplifier, though, because you can also get feedback there.

Another interesting circuit is his pulse counting receiver, as it uses no IF transformers.

I have a book that Peter gave me (Amateur Radio League) that has all sorts of superregenerative circuits. I haven't gotten around to trying them yet. One is a superheterodyne that uses a superregenerative detector. This greatly improves matters, and allows the superregenerative detector to be fine tuned, since it will only be handling one frequency. Another idea I had, which I've actually found in this book, is to have two superregenerative detectors working just above and just below the IF as a discriminator. I haven't tried it yet, but it might actually give truer FM, since it wouldn't be using slope detection. Good shielding would be essential, otherwise each circuit might radiate into the other.

T.

:http://www.users.bigpond.com/cool386/12at7/12at7.html
:
:I like this one. I built the superregenerative FM, though I didn't make my RF amplifier also perform as an audio reflexer.

Hi, can you share a picture? I'd like to see what yours looks like.

http://s244.photobucket.com/albums/gg39/bigbadpiratetom/?action=view¤t=FMSUPER1.jpg

Here are some pictures. I typed some fairly detailed descriptions of basic circuit construction and what kinds of tubes I used, but when I hit save none of it saved. I'm tired, and I don't feel like re-typing it anymore, so perhaps I'll do it some other time.

Here's another.

http://s244.photobucket.com/albums/gg39/bigbadpiratetom/?action=view¤t=FMSUPER2.jpg