"Bill M" wrote in message
...
Paul P wrote:



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.

Are you able to get the 5Mc point set ok?

Sometimes the solution is to fudge on the dial pointer alignment and
see if the other 3 bands can line up. However, if they are spot on now
that might not be the direction to go.

-Bill

Should not have to fudge anything. The top and bottom bands are good so the
Oscillator is good. The 5 mc band is off so there is a bad part connected
to the band switch. Fix or replace. Fudging always makes more problems.

I had an S-120 growing up
http://image08.webshots.com/8/8/80/8...3yhLWvj_fs.jpg
and later, S-38E for show.
http://www.woulfeman.com/Radio%20Hallicrafters.jpg
I was SWL long before I got around to the ham ticket.

Should not have to fudge anything. The top and bottom bands are good so
the
Oscillator is good. The 5 mc band is off so there is a bad part connected
to the band switch. Fix or replace. Fudging always makes more problems.

I had an S-120 growing up
http://image08.webshots.com/8/8/80/8...3yhLWvj_fs.jpg
and later, S-38E for show.
http://www.woulfeman.com/Radio%20Hallicrafters.jpg
I was SWL long before I got around to the ham ticket.


JB was the closest. After fussing with it for another two hours I started
tracing the padders on each band. What I found was very curios.

There was a rather original looking wire connected from the band 2 osc
trimmer (coil lug 20, see schematic) to one of the antenna coils (tab O on
the wafer switch). Why that was put there? I have not a clue. Once I
disconnected the trimmer side of the wire the oscillator snapped back into
alignment range. It tweaked in at both the 5Mc and 1.8Mc alignment points
dead nuts on.

I desoldered the switch side of the jumper (tab O). The joint looked rather
factory and not owner installed. Curious. The Trimmer side (coil lug 20)
was definitely messed with (short lead and burned insulation).

Ham owned gear. It's like a box of chocolates. Ya never know what you will
find.

Thanks to all for the comments. They did help focus me on the band 2
circuit.

Paul P.

Paul P wrote:

There was a rather original looking wire connected from the band 2 osc
trimmer (coil lug 20, see schematic) to one of the antenna coils (tab O
on the wafer switch). Why that was put there? I have not a clue. Once
I disconnected the trimmer side of the wire the oscillator snapped back
into alignment range. It tweaked in at both the 5Mc and 1.8Mc alignment
points dead nuts on.

Amazing! Kudos for finding it.

-Bill

"Paul P" REMOVE paul @ REMOVE ppinyot . REMOVEcom wrote in
message ...

"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.
OK then I wasn't wrong about which band was the
problem:-) However, in the Rider's manual from Nostalgia
Radio C-11 is shown as a fixed 2200 uuf cap.
I also found a PDF of the original Hallicrafters
handbook. This also shows a 2200 uuf fixed cap in the padder
position. The component numbers are different from the
Rider's sheets, in the Hallicrafter's book this cap is
called C-16 and is listed as a 600V mica. For band-2 the
only adjustment is the trimmer, C-21 (in the H book). If the
low end is off or if the entire band is off I suspect C-21
or else coil damage. The S-38 does have an adjustable padder
for Band-2 but the S-38A and S-38B do not. So, I suspect
someone added the adjustable cap for some reason, perhaps
because of the problem you are having. Anyway. I would
remove it, put a 2200 uuf mica cap there and see what you
get. If the thing is still off check the coils and value of
the trimmer, maybe someone substituted it.


--
Richard Knoppow
Los Angeles
WB6KBL

"Paul P" REMOVE paul @ REMOVE ppinyot . REMOVEcom wrote in
message news
Should not have to fudge anything. The top and bottom
bands are good so the
Oscillator is good. The 5 mc band is off so there is a
bad part connected
to the band switch. Fix or replace. Fudging always
makes more problems.

I had an S-120 growing up
http://image08.webshots.com/8/8/80/8...3yhLWvj_fs.jpg
and later, S-38E for show.
http://www.woulfeman.com/Radio%20Hallicrafters.jpg
I was SWL long before I got around to the ham ticket.


JB was the closest. After fussing with it for another two
hours I started tracing the padders on each band. What I
found was very curios.

There was a rather original looking wire connected from
the band 2 osc trimmer (coil lug 20, see schematic) to one
of the antenna coils (tab O on the wafer switch). Why
that was put there? I have not a clue. Once I
disconnected the trimmer side of the wire the oscillator
snapped back into alignment range. It tweaked in at both
the 5Mc and 1.8Mc alignment points dead nuts on.

I desoldered the switch side of the jumper (tab O). The
joint looked rather factory and not owner installed.
Curious. The Trimmer side (coil lug 20) was definitely
messed with (short lead and burned insulation).

Ham owned gear. It's like a box of chocolates. Ya never
know what you will find.

Thanks to all for the comments. They did help focus me on
the band 2 circuit.

Paul P.

Congratulations!!! I was about to post another answer
because I find that only the S-38 had a padder on this band,
the S-38A and B have just the 2200 uuf fixed padder.
As you say, who knows what that person thought they were
doing.
If the owner plays around with chain saws I can
understand why you wanted to please him.


--
Richard Knoppow
Los Angeles
WB6KBL

If the owner plays around with chain saws I can
understand why you wanted to please him.


--
Richard Knoppow
Los Angeles
WB6KBL

Yes. I should be seeing him today. He is an very active member of the
Skyview Radio Society ham club. He (and others) do a lot to promote Ham
Radio. He tried to talk the nurses into a VE session and getting their
license.

Paul P.

OK then I wasn't wrong about which band was the problem:-) However, in
the Rider's manual from Nostalgia Radio C-11 is shown as a fixed 2200 uuf
cap.
I also found a PDF of the original Hallicrafters handbook. This also
shows a 2200 uuf fixed cap in the padder position. The component numbers
are different from the Rider's sheets, in the Hallicrafter's book this cap
is called C-16 and is listed as a 600V mica. For band-2 the only
adjustment is the trimmer, C-21 (in the H book). If the low end is off or
if the entire band is off I suspect C-21 or else coil damage. The S-38
does have an adjustable padder for Band-2 but the S-38A and S-38B do not.
So, I suspect someone added the adjustable cap for some reason, perhaps
because of the problem you are having. Anyway. I would remove it, put a
2200 uuf mica cap there and see what you get. If the thing is still off
check the coils and value of the trimmer, maybe someone substituted it.


--
Richard Knoppow
Los Angeles
WB6KBL



Richard,

Where did you find that manual?

As a side note, if you look at the Nostalgia Air schematic it does show a
padder on the band 2 position and it is bolted on the chassis with access
holes from the top. Band 2 does have a 1200pf cap in parallel with the
padder that is needed to align the 1.8Mc point. That cap is NOT depicted on
the schematic. The padder does look factory as do the holes, wires and bolt
through the chassis.

And thanks again for all the comments and help,

Thanks, Paul P.

The culprit: http://www.ppinyot.com/H/Hallicrafte...8straywire.JPG

The rest of the story: http://www.ppinyot.com/s-38.htm

Paul P.

"Paul P" REMOVE paul @ REMOVE ppinyot . REMOVEcom wrote in message
news
Should not have to fudge anything. The top and bottom bands are good so
the
Oscillator is good. The 5 mc band is off so there is a bad part
connected
to the band switch. Fix or replace. Fudging always makes more
problems.

I had an S-120 growing up
http://image08.webshots.com/8/8/80/8...3yhLWvj_fs.jpg
and later, S-38E for show.
http://www.woulfeman.com/Radio%20Hallicrafters.jpg
I was SWL long before I got around to the ham ticket.


JB was the closest. After fussing with it for another two hours I started
tracing the padders on each band. What I found was very curios.

There was a rather original looking wire connected from the band 2 osc
trimmer (coil lug 20, see schematic) to one of the antenna coils (tab O on
the wafer switch). Why that was put there? I have not a clue. Once I
disconnected the trimmer side of the wire the oscillator snapped back into
alignment range. It tweaked in at both the 5Mc and 1.8Mc alignment points
dead nuts on.

I desoldered the switch side of the jumper (tab O). The joint looked
rather
factory and not owner installed. Curious. The Trimmer side (coil lug 20)
was definitely messed with (short lead and burned insulation).

Ham owned gear. It's like a box of chocolates. Ya never know what you
will
find.

Thanks to all for the comments. They did help focus me on the band 2
circuit.

Paul P.

Occasionally I find some equipment that never worked from the factory and so
escaped much wear and tear, being passed from one shelf to another. After I
acquire it for a song, I find a quality control issue. I got my IFR that
way.

"Paul P" REMOVE paul @ REMOVE ppinyot . REMOVEcom wrote in
message ...
OK then I wasn't wrong about which band was the
problem:-) However, in the Rider's manual from Nostalgia
Radio C-11 is shown as a fixed 2200 uuf cap.
I also found a PDF of the original Hallicrafters
handbook. This also shows a 2200 uuf fixed cap in the
padder position. The component numbers are different from
the Rider's sheets, in the Hallicrafter's book this cap
is called C-16 and is listed as a 600V mica. For band-2
the only adjustment is the trimmer, C-21 (in the H book).
If the low end is off or if the entire band is off I
suspect C-21 or else coil damage. The S-38 does have an
adjustable padder for Band-2 but the S-38A and S-38B do
not. So, I suspect someone added the adjustable cap for
some reason, perhaps because of the problem you are
having. Anyway. I would remove it, put a 2200 uuf mica
cap there and see what you get. If the thing is still off
check the coils and value of the trimmer, maybe someone
substituted it.


--
Richard Knoppow
Los Angeles
WB6KBL



Richard,

Where did you find that manual?

As a side note, if you look at the Nostalgia Air schematic
it does show a padder on the band 2 position and it is
bolted on the chassis with access holes from the top.
Band 2 does have a 1200pf cap in parallel with the padder
that is needed to align the 1.8Mc point. That cap is NOT
depicted on the schematic. The padder does look factory
as do the holes, wires and bolt through the chassis.

And thanks again for all the comments and help,

Thanks, Paul P.


Its on BAMA. I usually use the mirror site because its
much faster most of the time. See
http://bama.edebris.com/manuals/hallicra/s38b/
There is also a Sam's folder in the same place.

I suspect Hallicrafters made a lot of undocumented
changes at various times. The S-38 has a padder on the
second band but it faces the bottom.

I have both an S-38 and S-38B in the hopper except the
S-38B is in one of a couple of storage garages and I no
longer remember where. This was my first short wave receiver
bought by my parents new after a great deal of nagging. I
think I have become a defacto Hallicrafters collector
without meaning to.

--
Richard Knoppow
Los Angeles
WB6KBL