Podcasting since 2005! Listen to Latest SolderSmoke

Wednesday, August 21, 2019

Another Bout of Minimalist Regen Madness

My success with the Fish Soup 10 QRPp transceiver got me interested in further minimalization.  About ten years ago I built a rig presented in SPRAT 108 as the ET-1 by Glen Yingling W2UW.   It re-appeared in modified form as the FETer by G3XBM in SPRAT 137.  

This rig uses just ONE active device, an MPF-102 FET that is switched via a 3 pole double throw switch from transmit to receive.  The transistor is switched.  The receiver is a regen and the transmitter is a very simple crystal controlled one stage oscillator. See: 
https://soldersmoke.blogspot.com/search?q=ET-1  for info on my ET-1 effort. 
The transmitter was the easy part.  I don't think I made any contacts with this thing.  That has been kind of bugging me.  

So I tried it again.  Again, I had trouble with the receiver.  So I looked around for another single FET regen receiver design.   I found one on AA7EE's page.  It was designed by N0WVA:  

I've had a variometer in my junk box since about 1994. (Given to me by Pericles HI8P. QEPD.) It was time to use it as the coil and ticker for this rig.   I liked the green LED in the source, and the promise that this thing would not oscillate at audio frequencies.  

I built in on one morning.  See pictures. It works.  I can hear CW stations.  But I think I would have a tough time making contacts with this thing.   OM Yingling worked 24 states with his ET-1.  Respect.  


  1. You are so going to love retirement Bill!

    - Tony G4WIF

  2. Respect indeed!

    Tony's right ^^

  3. Add an LC audio low pass filter and fine tuning? Might help

    Ed KC8SBV

  4. Bill,

    I just finished an SSDRA low pass audio filter, just what your regen needs, but it uses 5 2N3904s, and not minimalist at all. I'm happy it works, and works well. Hope you get your one FET receiver usable.

    Ed KC8SBV

  5. Bill, it's great to see you get back to QRP CW, and give the computer chip rigs a break! And that it's a regen is even better, given your past sentiments about regens, HI HI. I don't see any mention of any chickens being sacrificed to Papa Legba, and it still works. True mojo! Keep 'em coming, thanks for all you and Pete do.



Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column