1-Tube Regenerative Receiver (page 1 of 2)

Hello, and welcome to Big Nick's Alfred Morgan
1-tube regenerative receiver page!

This project was my first regenerative radio
receiver and one of my favorites as well.
I won't forget how exciting it was for me to
build such a humble radio that so greatly out-
performed the crystal receivers that I had been
building up to that point.

The project comes from Alfred P. Morgan's "First Book of Radio and Electronics".

In the particular edition that I have, he uses a 6BF6 which is still available if you look hard enough.
I understand that the first edition of the book used the 1H4 tube. 
I have elected to use a 6C5.

The 6C5's heater can be powered by 6.3 V AC or DC.  (I believe that it may be more rugged that the 1G4 who's filament is "sensitive" to burn-out if overpowered.)

I've used several other contemporary components:  A 365 pF tuning capacitor, available from several WEB based parts vendors, an open frame antenna trim capacitor, new-fangled grid-leak resistor & capacitor, ceramic tube sockets, tuning vernier, etc. and they all work just fine!

You may want to mount your trimmer capacitor differently than I did, as mine suffers from hand-effect when trimming the antenna adjustment.  I'd suggest moving it back from the front panel and adding an insulated shaft extension.

Of course, don't expect iPod audio quality from this unit .. But I think that the performance is amazing considering that this circuit is designed around a single triode, just as FM Armstrong had designed it many years ago!

The audio samples that I'm presenting include some 'static' from a pending thunderstorm moving thru .. but that's part of the 'charm' and character of AM HF communications :-)

Click the speaker icons to hear the radio in action: 
Morse code: demodulated SSB: more demodulated SSB: ,

Here is the original text in pdf format.

Close up 1
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Close up 6

ISBN 0-684-14756-4 pbk