Thanks for that. It seems to work OK. Nice straightforward circuit too.

Hi. I've tried a couple of times. The signal to noise remained the same, when you reach the critical point. You can get more audio output from it. I've never been convinced there is much advantage. I'd be interested to here what results other people have found.

Hi. I built one 50 or so years ago with my dad. It worked well with a long antenna. Still giving station separation.

Amazing. And all from 1.2 volts. Thanks for the link. I've not got around to reading it as yet but it looked interesting.

Yes, they're a recipe for disaster really. The aim is to hold a circuit at the transition just before oscillation occurs. Possibly break it into two stages. A regenerative amplifier followed by a detector. It all depends on what you're aiming to achieve. If you're out for maximum gain from one device a reflex circuit is probably the answer. I'd be interested to see Robinsons paper. Any chance you could post a link?

Hi. It will demodulate. The transistors are only just biased on. They'll amplify the positive cycles far more than the negative. I see you mentioned AGC in one of your posts. Most regen detectors have AGC as the base coupling capacitor charges negative, reducing the gain as the signal increases. If you set it to the point where its just oscillating. As you tune to a station it will be pushed out of oscillation as the gain is reduced. This is bought about by the coupling capacitor on the first transistor.

That's good to know. Perhaps it was the guys layout. It would be interesting to see a video of yours operating.

There's a two transistor one I did some years ago, if that's any help. I ac coupled the two transistors and followed with a biased diode detector. Follow the link below. https://www.flickr.com/gp/79580324@N04/MNsFXZN9p5

I notice in the write up the guy says he can't stop it regenerating at the high end. How do you find It?

It's one of the problems using emitter followers at rf. They have a tendency to self oscillate. Sir Douglas Hall did a 2 transistor regen with speaker output. http://www.spontaflex.free-online.co.uk/begin/page2.jpg The circuit would need updating. See what you think.

Hi. The regeneration comes from the Darlington transistor. If you redraw it as two transistors the base emitter capacitance on each transistor form a capacitive tap for a Colpitts oscillator.

Hi Larry. Have you tried any of Sir Douglas Hall's circuits?

Thanks. I saw that. I was wondering if anyone had a video of it operating. It's an interesting circuit. Perhaps I'll put one together when I get the time.

Interesting circuit. Has anyone tried it?

My pleasure.

The Chineese are remanufacturing these. Unfortunatley the scale is over 300 degrees. But it may be of some help. Try this web address:- RV24YN Series Button Linear Digital Knob SB360 RV30YN Potentiometer Switch Knob Hole Diameter 6mm - AliExpress

Thank for the comment Larry. I've used a plain wire for years but the electrical noise got worse and worse. A short doublet seems to do the trick. I've just added a video of the antenna working with an ATS20+.