Homebrew: N1TEV Kitchin Regenerative Reciever
After speaking with my good friend Jeff (N9IZ), he got me interested in building a regenerative receiver. Jeff shared with me several YouTube links that have receivers like this that many hams and experimenters have built.
This particular receiver design comes from Charles Kitchin N1TEV. His design is a modification of a classic design that dates back to the 1920’s. The main modification is the use of the LM386 audio amplifier IC to give it a little better volume control, the use of 2N2222A transistors (instead of tubes), and the diodes that go to ground to improve regeneration.
When I decided that I would like to build a regenerative receiver and researched different designs, I settled on this one because I have heard that it is the most successful of the designs.
Originally detailed in the September, 2000 issue of QST magazine, the article that describes the design and details the circuit is available online here. There is a comprehensive parts listing complete with RadioShack part numbers for almost all components with the exception of the variable capacitor that is used for tuning (air-dielectric variable 150-350 pF). However those variable caps should be fairly easy to find, and most hams may even have one lying about or in something that could be scavenaged (like another old radio 😉 ).
This will be a multi-part build so, once I get the parts in I will document and maybe even make a video of the build. I think Jeff is going to build one with me, so that should be a lot of fun as we curse our way through the problems of the build and getting the thing to work correctly. I plan on making mine work on the 40m band. I thought that would definitely be more useful than another AM broadcast band radio, and then who knows, maybe Ill make a 40m transmitter as well. The regenerative receivers are pretty cool since they do not need a BFO or other circuitry to tune in AM, SSB or CW signals well. Just a touch of the regeneration control will help tune all signals in loud and clear. Well, im off to order the parts to put this together, so see you soon!
73! de Nick N9SJA
Have you started building yet?
I started one last night, but I’m using the circuit that has two 2N2222 transistors as the audio amp instead of the LM386. I’m using a wooden base with an aluminum panel. I think it will give it more of a “home made” look, like an old crystal set.
Yes, I got the board and started to assemble the components as you can see from the “part 1” of the series. I’m still waiting on a few other parts to ship. Still haven’t found a good enclosure yet that is reasonably priced. I have seen some of the “home made look” sets and they are very impressive. I watched several YouTube videos about them. I’m not really going for an old school look. Just max performance that I can get for homebrew. I like things from the 50’s and 60’s era and was looking for a reasonably priced metal cabinet that I can paint turquoise or some 50’s ish color. I thought that might be cool for mine anyway.
As soon as I get the parts in there will be a part 2 to this build. I am having fun with it and it should be as fun to use as it has been to build! Good Luck to you on your build!!!
73! de Nick N9SJA
I finished my radio. It’s picking up hams and broadcasts, but the audio output is so low I can barely hear it. I’m tearing out the two 2N2222 transistors and going for the LM386 IC amplifier, so my circuit will match your schematic when I’m done.
Awesome. I think the LM386 will help you. There is enough power to drive a small 8 ohm speaker with that so that it sounds good. The big thing with the schematic to note is the 3 diodes that go to ground. I chose this design because the diodes are supposed to help with regeneration. Most of the other designs don’t use them and have problems with regeneration.
I would love to see your build. If you want, you can send me photos and I’ll make a post about it here. Maybe a little write-up if you want about any specifics you did with your build. I know my regular blog readers (all 10 of them 😉 would love to see it!
Sounds like you got it going well if you are receiving stations. When I get mine all done with the cabinet and everything I think I may make a short video and post it as well.
It’s great that people still build these. Although it is WAY more expensive to build one than to just buy an AM radio. I think I have over $80 in mine. I’ll have to make a post just about the costs. RadioShack is expensive for parts and even internet ordering inst really that convenient since you usually have to buy in such large quantity. Digi-Key and Mouser all want me to buy like 100 or 500 of a diode or something that I just need 1 of.
Anyway, nice to meet you and good luck to you!
73! de Nick N9SJA
Thanks, I’ve wondered what the diodes were for.
I bought most of the parts here: http://partsexpress.com/
That’s “parts express”, not “part sex press”. LOL!
Disk capacitors are 7 cents. So are resistors, but you have to buy ten resistors at a time. Everything comes labeled in zip lock bags, so you don’t even need to look at the part to identify it.
I can’t figure out how to upload photos. Any hints would be helpful.
By AE5VM. A friend on Facebook gave me two boards a yr ago and I now just tackled the building of one… I used a 27-29pf variable capacitor and placed an 80 some pf in parallel with the variable. I got a portion of 49m and 40m… Listen to this: https://www.youtube.com/watch?v=yUDFJN9qXp8&t=37s