[Hallicrafters] S-38C dial tracking and AGC

[Glen Zook]

Considering that the i.f. frequency in the S-38 series
equipment is 455 KHz, and the fact that you can't vary
it more than +/- 5 KHz (and probably less), the i.f.
frequency alignment isn't going to make any difference
in the calibration!  It only means that the injection
oscillator is going to be shifted up to 5 KHz in
either direction and, frankly, you can't tell that
difference in the calibration of the S-38 series dial!

Now, you can run into problems with images and align
the dial at one end or the other on the image which is
910 KHz away from the desired frequency.  That will
cause all sorts of problems with the dial accuracy
since you think that it is on one frequency at the low
end and another at the high end.

Single conversion receivers are VERY prone to images
especially on the higher frequency bands especially
with lower i.f. frequencies.

Glen, K9STH


--- Craig Roberts <crgrbrts at verizon.net> wrote:

Regarding the dial tracking, he makes a very good
point about IF alignment.

=====
Glen, K9STH

Web sites

http://home.comcast.net/~k9sth
http://home.comcast.net/~zcomco

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