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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:  
https://aa7ee.wordpress.com/2015/02/07/n0wvas-one-fet-regen-optimized-for-ssbcw-sounds-great/


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.  


6 comments:

  1. You are so going to love retirement Bill!

    - Tony G4WIF

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  2. Respect indeed!

    Tony's right ^^

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

    Ed KC8SBV

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  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









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  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.

    N7REP
    Rob

    ReplyDelete

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