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Old November 22nd 06, 08:10 PM posted to rec.radio.amateur.boatanchors
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Posts: 26
Default hallicrafters s-40a, bad band(s)

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
vol. recapped (not micas) and tested all tubes, replacing as needed.
checked resistors, and replaced a few. set also had severe crackling
which matched 'short in a tuning cap' as described in marcus and levy.
i replaced the tuning condensor, due to remaining crackles i simply
couldn't get out w/cleaning. crackles went away w/partswap and set
appeared to align well -- used scope across output to voice coil. got
good volume and nice waves as i went thru the IF and the band steps.
for IF the sig gen was connected to the center of the gang, the middle
of 3 posts on the top of it, w/the ground to the chassis and the gang
fully open.

radio plays well on band 3 -- good vol on strong station, many stations
w/short wire. picks up similarly on band 2 down to about 4 mhz.

bc is silent except for what sounds like a couple of spots that 'want
to be' stations. very faint voice heard in one spot. band 4 seems to
be similar.

a quick reattach of sig gen, and good tones heard all bands at align
freq for those bands, and good IF tone. bandswitch was checked and
cleaned. seems to be making good contact w/clean click/pop as changed
w/set on. a little puzzled where to look because of this.

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

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Old November 22nd 06, 08:39 PM 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...
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
vol. recapped (not micas) and tested all tubes, replacing as needed.
checked resistors, and replaced a few. set also had severe crackling
which matched 'short in a tuning cap' as described in marcus and levy.
i replaced the tuning condensor, due to remaining crackles i simply
couldn't get out w/cleaning. crackles went away w/partswap and set
appeared to align well -- used scope across output to voice coil. got
good volume and nice waves as i went thru the IF and the band steps.
for IF the sig gen was connected to the center of the gang, the middle
of 3 posts on the top of it, w/the ground to the chassis and the gang
fully open.

radio plays well on band 3 -- good vol on strong station, many stations
w/short wire. picks up similarly on band 2 down to about 4 mhz.

bc is silent except for what sounds like a couple of spots that 'want
to be' stations. very faint voice heard in one spot. band 4 seems to
be similar.

a quick reattach of sig gen, and good tones heard all bands at align
freq for those bands, and good IF tone. bandswitch was checked and
cleaned. seems to be making good contact w/clean click/pop as changed
w/set on. a little puzzled where to look because of this.

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


First, carefully clean the band switch wafer metal wipers with a cotton
Q-tip and some DeOxit.
No need for heavy handiness here -- just good patient (methodical) cleaning.
IF you are short on time or not patient that day -- do something else and
come back to it.

gb


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Old November 22nd 06, 09:28 PM posted to rec.radio.amateur.boatanchors
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First recorded activity by RadioBanter: Nov 2006
Posts: 26
Default hallicrafters s-40a, bad band(s)

have done, 3 times, just as you say. the fingers seems to make good
contact (rise and fall as the switch is cycled). i can certainly do
again. i guess what i don't get is how i can get a nice signal thru
w/the gen -- tune the test signal and its images, but not tune
stations. i don't have a whole lot of experience w/this.
ab

First, carefully clean the band switch wafer metal wipers with a cotton
Q-tip and some DeOxit.
No need for heavy handiness here -- just good patient (methodical) cleaning.
IF you are short on time or not patient that day -- do something else and
come back to it.

gb


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Old November 22nd 06, 11:19 PM posted to rec.radio.amateur.boatanchors
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First recorded activity by RadioBanter: Jul 2006
Posts: 100
Default hallicrafters s-40a, bad band(s)

ablebravo wrote:
have done, 3 times, just as you say. the fingers seems to make good
contact (rise and fall as the switch is cycled). i can certainly do
again. i guess what i don't get is how i can get a nice signal thru
w/the gen -- tune the test signal and its images, but not tune
stations. i don't have a whole lot of experience w/this.
ab

First, carefully clean the band switch wafer metal wipers with a cotton
Q-tip and some DeOxit.
No need for heavy handiness here -- just good patient (methodical) cleaning.
IF you are short on time or not patient that day -- do something else and
come back to it.

gb



Perhaps you are simply trying to receive stations on bands for which
there is poor propagation during that particular time of day....

jak

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Old November 22nd 06, 11:34 PM posted to rec.radio.amateur.boatanchors
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First recorded activity by RadioBanter: Jul 2006
Posts: 69
Default hallicrafters s-40a, bad band(s)

I believe your antenna coil is open...Look at schematic and find
BC band coil,check continuity from ant post to ground... coil is
probably open..This sometimes happens when lightning sends a surge via
an external antenna,burns out the ant coil on the band that is selected
at the time..You may be able to repair the coil if that is the
problem...GL HS
jakdedert wrote:
ablebravo wrote:
have done, 3 times, just as you say. the fingers seems to make good
contact (rise and fall as the switch is cycled). i can certainly do
again. i guess what i don't get is how i can get a nice signal thru
w/the gen -- tune the test signal and its images, but not tune
stations. i don't have a whole lot of experience w/this.
ab

First, carefully clean the band switch wafer metal wipers with a cotton
Q-tip and some DeOxit.
No need for heavy handiness here -- just good patient (methodical) cleaning.
IF you are short on time or not patient that day -- do something else and
come back to it.

gb



Perhaps you are simply trying to receive stations on bands for which
there is poor propagation during that particular time of day....

jak




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Old November 22nd 06, 11:34 PM posted to rec.radio.amateur.boatanchors
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First recorded activity by RadioBanter: Jul 2006
Posts: 69
Default hallicrafters s-40a, bad band(s)

I believe your antenna coil is open...Look at schematic and find
BC band coil,check continuity from ant post to ground... coil is
probably open..This sometimes happens when lightning sends a surge via
an external antenna,burns out the ant coil on the band that is selected
at the time..You may be able to repair the coil if that is the
problem...GL HS
jakdedert wrote:
ablebravo wrote:
have done, 3 times, just as you say. the fingers seems to make good
contact (rise and fall as the switch is cycled). i can certainly do
again. i guess what i don't get is how i can get a nice signal thru
w/the gen -- tune the test signal and its images, but not tune
stations. i don't have a whole lot of experience w/this.
ab

First, carefully clean the band switch wafer metal wipers with a cotton
Q-tip and some DeOxit.
No need for heavy handiness here -- just good patient (methodical) cleaning.
IF you are short on time or not patient that day -- do something else and
come back to it.

gb



Perhaps you are simply trying to receive stations on bands for which
there is poor propagation during that particular time of day....

jak


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Old November 22nd 06, 11:34 PM posted to rec.radio.amateur.boatanchors
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First recorded activity by RadioBanter: Jul 2006
Posts: 69
Default hallicrafters s-40a, bad band(s)

I believe your antenna coil is open...Look at schematic and find
BC band coil,check continuity from ant post to ground... coil is
probably open..This sometimes happens when lightning sends a surge via
an external antenna,burns out the ant coil on the band that is selected
at the time..You may be able to repair the coil if that is the
problem...GL HS
jakdedert wrote:
ablebravo wrote:
have done, 3 times, just as you say. the fingers seems to make good
contact (rise and fall as the switch is cycled). i can certainly do
again. i guess what i don't get is how i can get a nice signal thru
w/the gen -- tune the test signal and its images, but not tune
stations. i don't have a whole lot of experience w/this.
ab

First, carefully clean the band switch wafer metal wipers with a cotton
Q-tip and some DeOxit.
No need for heavy handiness here -- just good patient (methodical) cleaning.
IF you are short on time or not patient that day -- do something else and
come back to it.

gb



Perhaps you are simply trying to receive stations on bands for which
there is poor propagation during that particular time of day....

jak


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Old November 23rd 06, 12:07 AM posted to rec.radio.amateur.boatanchors
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First recorded activity by RadioBanter: Nov 2006
Posts: 26
Default hallicrafters s-40a, bad band(s)

checked against a zenith transoceanic, same bands same time of day. i
guess a better phrasing would be, 'could misalignment (image maybe)
cause these problems. i will check the coil, but suspect ok. before
pulling the old tuner cap, could receive bc outside the areas it was
crackling on.
ab
jakdedert wrote:
ablebravo wrote:
have done, 3 times, just as you say. the fingers seems to make good
contact (rise and fall as the switch is cycled). i can certainly do
again. i guess what i don't get is how i can get a nice signal thru
w/the gen -- tune the test signal and its images, but not tune
stations. i don't have a whole lot of experience w/this.
ab

First, carefully clean the band switch wafer metal wipers with a cotton
Q-tip and some DeOxit.
No need for heavy handiness here -- just good patient (methodical) cleaning.
IF you are short on time or not patient that day -- do something else and
come back to it.

gb



Perhaps you are simply trying to receive stations on bands for which
there is poor propagation during that particular time of day....

jak


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Old November 23rd 06, 03:05 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
oups.com...
have done, 3 times, just as you say. the fingers seems to make good
contact (rise and fall as the switch is cycled). i can certainly do
again. i guess what i don't get is how i can get a nice signal thru
w/the gen -- tune the test signal and its images, but not tune
stations. i don't have a whole lot of experience w/this.
ab

Well if you removed visible tarnish (brown or black) you are then
likely okay in that department.

You have performed the alignment, right?

gb


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Old November 23rd 06, 03:34 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...
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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