I have a Reciprocating Detector that I built from a kit of parts that I purchased
from W1SNN back in 1972. I use it at 455kHz in an AM broadcast receiver to
eliminate selective fading.

The IEEE Comm paper by Badessa lists the patent on the RD that you can look up.
Also if you get a null in the center of the lock range you may be locking 90
degrees out of phase with the carrier.

Bob K4QQK

Michael Black wrote:

"Tom Holden" ) writes:
I've been tinkering with an add-on project for a RS DX-394 receiver based on
Stirling Olberg's (W1SNN) "Reciprocating Detector" design(s) published in
Ham Radio in 1972 to 1978. Has anybody had any experience with this design.
Is it fundamentally any different from a synchronous detector such as the
NE602 design by OH2GF in the current ARRL Handbook?

Tom


I've read those articles, and specifically reread them last year, and
for the life of me I really not sure how it's supposed to work. The way
he explains it, it sure seems like there is some specific little bit that
is happening in there. If I'm remembering, he claims it works for FM
too, and I don't see how it could demodulate FM if it was just a synchronous
detector.

He references some professional article or paper as the source of
scheme, and one would hope if someone could get ahold of that, what
is going on might be clearer.

When I did some searches on the internet last year, I sure didn't find
anything more about it. A handful of Usenet posts, none of which added
to the scheme or even an understanding of it.

Michael VE2BVW