"Richard Knoppow" wrote in message
...
On Apr 14, 6:38 pm, Bill M wrote:
Richard Knoppow wrote:
Looking at the schematic it appears that bands 1 and 2
have fixed padders in them. For Band-2 its C-11, a 2200 mmf
cap and probably one of the postage stamps. If this has
changed value it will throw off the band. I think this is
more likely than the coil having shifted. This is a common
value so a replacement should not be hard to find. I suggest
changing it before doing anything else.

Trying to follow your posts across the different forums.

The 38 is a plain jane AA5 with shortwave bands, Don't try to read too
much into it. Image rejection is so poor on the top band that it really
makes little difference as to how you tune it. You're welcome to try,
though.

I'm glad you wrote because I mistook the band Paul was trying to
align. Its band -3 which does not have a padder. So, if nothing else
seems wrong the coil may need tweeking.
I am pretty sure all the bands on the S-38 series tune with the
LO above the signal frequency. One can always try it below. If that's
wrong it won't track properly.
I don't think it has any image rejection at the upper part of
the top band:-)

Richard Knoppow
WB6KBL


Gentlemen,
A point of clarification:

Band 2 is the problematic band. It covers 1.650 to 5 MHz. The 5MHz is the
oscillator set point. The padder is to be set at 1.8MHz and does not even
come close with the difference at the 5MHz Osc Trimmer error. This band is
aligned after the 455 IF, BFO and two higher bands are aligned. After this
band is the standard broadcast band.

The padder C11 on band 2 is a variable cap with a postage stamp (domino) in
parallel. I disconnected this parallel cap in hopes of raising the overall
oscillator frequency to align to 5MHz with no success. It barely made a
difference (no big surprise here).

The other bands align properly starting with Band 4, 13.5 - 32 MHz,
band 3, 5 - 14.5 MHz and last
band 1 broadcast.

I will also check C9 (2700 or 3000pf) in series with the tuning gang on a
hunch. It may have some low end affects. I did not attempt to calculate
the low end cut off point (collage was too long ago). The band spread has
been set to Zero in accordance to the alignment procedure page 15-62.

I did use carbon composition resistors in front of the first IF for Rs 1, 2,
3, 20 & 21.

I will try all the suggestions today. I spoke with the owner yesterday. He
wound up in the hospital with a chainsaw gouge in his leg. He and another
were at our ham club cutting trees and had an accident. I want to get this
chassis working great for him. Your help is helpful.

As always, thanks for all the input!

Paul P.