"Scott Dorsey" wrote in message
...
Henry Kolesnik wrote:
The secondary of the IF xfmrm feeding the diode will have
a different
winding than the first two. My transformer theory is not
up to snuff,
I'm 68 and if I recall correctly a diode has a much lower
input
impedance that has to be matched so I'm guessing it will
have less
turns. Remember that a transformer reflects the impedance
back.
You may want to get a copy of The Radiotron Designers
Handbook by
Langford, it covers just about anything you would want to
know about
tube radios, over 1000 pages.

The over 1000-page one is the Fourth Edition, which is the
most expensive
on the used market, and the one which has the most hi-fi
information in
it.

The discussion of IF strip design is also in the smaller
and much less
expensive Third Edition. Some people like the third
edition because it
has some information on transformer design which was not
carried into
the fourth.

A copy of the fourth edition is available online he
http://geek.scorpiorising.ca/RDH4.html
--scott
The forth edition is available in PDF form from Pete
Milette's site:
http://www.pmillett.com/
Along with many other classic books including
K.R.Sturley's two volume book on radio receiver design. The
organization of the site is a bit confusing so a bit of
poking around in needed to find everything. The quality of
his scans is excellent but the files are _very_ large and
really require a high speed connection to be practical.
I also recommend the 4th edition of the Radiotron, I
think I have two, the one I bought new fell apart from use
(rebound it). The 3rd edition, which is much smaller, also
has a lot of useful information in it.
I agree with the statements made about the final IF
transformer but not all detectors offer low impedance to the
transformer although this is true of straight diode
detectors. Both of the above books have thorough discussions
of AM detectors and their relative merits.

--
Richard Knoppow
Los Angeles
WB6KBL