"- - Bill - -" exray@coquidotnet wrote in message
...
Uncle Peter wrote:


Just a few general notes if no answers forth coming:

1: Measure the LO with a counter at the low end (if there is no
adjustment for setting the low end of the tuning);
that will tell you if that band uses hi or lo side injection.
It makes a big difference if set wrong!!!

Not on an S-38! It probably won't track well enough to determine for
sure.


2: If the osc. section of the tuning cap uses smaller sized plates,
the
radio is probably hi side injection.

Ya might want to rethink that suggestion Pete. Any set with AM band on
it will have smaller osc plates.

I was recently struggling with a cheapo little SW radio and it
tracks/tunes/rejects images about the same (which means not very good)
no matter which way ya go on the upper band. Low side may have had an
edge in this particular case but it would take a jury of sharp-eared
engineers to decide.

-Bill M


1: It doesn't matter providing the set has fixed inductors;
the small-value trimmer used for setting the high end will not have enough
authority to permit setting injection improperly on the low end of the
tuning.
A frequency counter will usually determine the correct LO side for injection
if you check the LO at the low end of the tuning range.
You can set it wrong on the high end of the tuning range, but the radio
will
work like crap midband where it still has some front end selectivity.
You may think it is working, but unless you check
it across the full tuning range you might be surprised

2: The majority of sets I collect seem to have equal sized plates in the
osc. and mixer/rf sections? I don't think the offset oscillator section
came
into vogue until the late 30s or early 40s??

Pete