"Alan Horowitz" wrote in message
om...
Is there a place in modern technique for regeneration (Q-multiplication)?

I guess that depends on the application. I don't know how true it is, but I
believe I saw that some of the 433 MHz ISM band receivers use either
regenerative or superregenerative detectors. They are tiny and have
sensitivities better than -106 dBm.

There has been new work on superregens (September/October 2000). An article
was published in QEX, a ham radio journal. The first file at
http://www.arrl.org/tis/info/vhfproj.html is that article but it requires
membership to get it. However, on the same Web page, I see another that
appears to be available without membership. It is An Ultra-Simple VHF
Receiver for 6 Meters .

You can probably contact the ARRL and buy a reprint of the first article. It
is well worth it. The author, Charles Kitchin, says the gain in a superregen
detector is about a million. He discusses his discovery of shaping the
quenching waveform so that selectivity is not lost. And he says it is
possible to receive FM and NBFM as well as AM. It is a very enlightening
article.

I plan to build a superregen to play with. After I get one going, I think I
will try to make it work at 450 MHz. Like some other posters here, I built
my previous regen 40 years ago.

Cheers,
John