In article , "Jim, N2VX"
writes:

On Mon, 19 Jan 2004 04:18:19 -0000, Pete Beals
wrote:

Yes most used AM stereo demodulators but those IC's might not be sold
anymore.

There must be reasonable implementations as many shortwave receivers have
sync detectors.

I just need one to demodulate AM.


Pete
I think that "as few parts as possible" and "works good" are probably
somewhat mutually exclusive. Have you done the usual google and
altavista searches on "synchronous detector"?

A long long time ago one appeared in the user-contributed circuits
section of Electronic Design magazine. Don't remember the name of the
column but it was always good. They also used to publish circuit
collections from the column every few years. Lots of clever ideas:
"Build this quadraphonic stereo receiver with a single CMOS interter"
is just a slight exaggeration. I remember reading the magazine up to
the early 90's. Don't know what happened to them.

Electronic Design is online at http://www.elecdesign.com

Their newer website makes it a bit difficult to search for Design
Ideas in past issues. Those probably don't go back farther than
2001 but I could be mistaken. Source code for those column
pieces requiring source is available as separate text files.

EDN is online at http://www.reed-electronics.com/ednmag

EDN's Design Ideas go back only to 1995...but are easier to
access.

The synchronous detector used two analog multiplier chips and as I
recall was contributed by someone with a callsign. Don't remember any
other details. Anybody remember the magazine and the column?

I still get both Electronic Design and EDN, plus RF Design and
Microwaves & RF. Used to cut up the issues after a month or so
and file them for reference...until they all got on-line and I could
write them onto a CD (much easier to reference, less space).

Don't recall the article or didn't bother to log it in memory as
"important." :-) :-(

Motorola quit a whole bunch of specialty ICs a bit ago, very few
showing up on other websites. They made a nice stereo AM IC that
had an automatic synchronous detection system. Not enough
market demand for it. ON Semiconductor still makes a few of the old
Motorola line.

Len Anderson
retired (from regular hours) electronic engineer person