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Old November 23rd 06, 03:34 AM posted to rec.radio.amateur.boatanchors
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Default hallicrafters s-40a, bad band(s)

"ablebravo" wrote in message
ups.com...
this is the first more complex (than s38s) halli have i tried to
repair. as received, the set. set played, but w/out sensitivity or
volume ... [snip].
docs say make sure the image freq is out of the way of oscillator freq
for bands. i don't quite understand what this means, or how to be sure
they aren't colliding, but i think i may have misaligned the base IF?
maybe aligned with an image of it? have noticed when aligning other
sets, you can find several positions that ring w/the tone, but only one
that rings best. is this the result of getting the echo instead of the
original? care was taken on the rf aligns to find thru most of the adj
range for the best response. but did not try moving the if's
radically.
ab


Yes, after I reread your first post -- you may have aligned this incorrectly
Bruce McCalley has a good article on this subject for restorers
http://www.antiqueradios.org/gazette/align.htm

OR it may be ....
http://www.burnyourbonus.net/rec.rad...thread306.html

http://bama.sbc.edu/hallicra.htm

I would suggest looking at these S-40A web pages (and owners who have also
performed major restorations and alignments on this model)

Phillip I. Nelson (a good documentation restorer)
http://antiqueradio.org/halli02.htm

VE7SL
http://imagenisp.ca/jsm/s40.html
"A close inspection of the BFO circuit indicated a previous but unsuccessful
repair attempt. As the Hallicrafter's engineers often liked to do in BFO
circuits, a gimmick capacitor consisting of two short twisted wires was used
to couple the BFO signal into the detector. This particular S-40 had one of
the two wires soldered to the correct tube pin but the other one (to twist
together with) was not to be found. Examining the tube pin showed no
indication that there ever had been a second wire as the solder was smooth,
original and undisturbed. The one wire that was installed showed no
indication of ever being twisted with another. It is likely that the BFO
circuit on radio 12,733 never did work, right off the Rogers Majestic
assembly line in Toronto.
Perhaps it was wired or tested very late on a Friday afternoon, back in
1947! "

http://portabletubes.co.uk/boats/hs40.htm


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Old November 23rd 06, 04:33 AM posted to rec.radio.amateur.boatanchors
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Default hallicrafters s-40a, bad band(s)

yep using bama copy halli s40a service guide. have sams. reread phil
for first 4 sets i did. will read bruce w/interest, but some over my
head. think i will retry if align since cleaned band again w/no
change. band rotors look pretty good. have located the band 1 related
coils and will try to figure out how to test for opens....4
solderpoints per coil.... not sure which should be connected to meter.

thank you all for your patience and advice
ab

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Old November 23rd 06, 04:43 AM posted to rec.radio.amateur.boatanchors
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First recorded activity by RadioBanter: Oct 2006
Posts: 134
Default hallicrafters s-40a, bad band(s)

"ablebravo" wrote in message
ups.com...
yep using bama copy halli s40a service guide. have sams. reread phil
for first 4 sets i did. will read bruce w/interest, but some over my
head. think i will retry if align since cleaned band again w/no
change. band rotors look pretty good. have located the band 1 related
coils and will try to figure out how to test for opens....4
solderpoints per coil.... not sure which should be connected to meter.

thank you all for your patience and advice
ab

Richard reminded me of one other point .. check you coils in the BC (band
1).

Phil found bad capacitors in some of these sections or inside cans (great
way to ruin the day) ...
finding and replacing resolved his sensitivity and peaking.
Note that many have commented that sensitivity was lousy (compared to what?)
on band 1.

gb


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