No stations picked up by my S-38C! Bad cap? Help!
Matt Senecal
speaker works, I get a hum when I tune, but where it should be picking
up stations there's nothing. Even local AM stations that should be
coming through loud and clear aren't picked up. All the tubes are OK.
I don't know a lot about old radio circuits (yet :) ), but I suspect
that one of the capacitors is blown. Short of replacing everything,
can anyone suggest a part(s) that I might want to check?
Thanks in advance,
Matt
Uncle Peter
Pete
"Matt Senecal" <msen...@juno.com> wrote in message
news:62bf14a6.02062...@posting.google.com...
w9gb
If you are unfamiliar with the repair of older tube (now antique) receivers
or replacement of parts, ask the advice of your local restorers or
professional radio shop.
Ground Up Restoration (a great primer)
http://antiqueradio.org/groundup.htm
Hallicrafters S-38C.0.54-32MHz AM/CW 6-tube short-wave receiver. 1946.
A nice set with fine selectivity, excellent band spread, and great audio.
Usually a good performer in AM DXing as well. A nice, inexpensive vintage
set.
Stan Watkins has a good web page, with photographs on his restoration of the
S-38 receiver.
http://www.concentric.net/~Stwradio/hals38.htm#Hallicrafters%20S-38%20Restor
ation
Phil Nelson also has some notes on restoring the S-38 receiver.
http://antiqueradio.org/halli08.htm
Electrolytic capacitors (and paper capacitors) can dry out as they age (hey
this receiver is easily over 40 years old). The audio hum you hear
indicates you may have this specific problem. Here are some links for
replacing antique radio capacitors:
http://www.ezlink.com/~crash/parks/caps.html
http://antiqueradio.org/recap.htm
NOTE: This receiver has rubber isolators that keeps line voltage (110 VAC)
off the metal cabinet. There are four isolators, one on each corner.
These MUST be replaced properly, if the radio is going to be operated
SAFELY, without an isolation transformer. [See Stan Watkins web page for
photographs]
If I was restoring this receiver, I would get a schematic and replace the
electrolytic and paper capacitors.
Available at: http://bama.sbc.edu/hallicra.htm
Greg
w9gb
PS Discussion of this receiver is quite frequent on boatanchors, check
archives for the December 2001 discussions.
"Matt Senecal" <msen...@juno.com> wrote in message
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w9gb
"Matt Senecal" <msen...@juno.com> wrote in message
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Silicon Geek
msen...@juno.com says...
I hate to tell you this, but you should replace everything, or at least
every capacitor. If you are going to use it regularly you don't want to
dig through the underside with a multimeter to discern which cap blew
this time.
:-) Bill
>
> I hate to tell you this, but you should replace everything, or at least
> every capacitor. If you are going to use it regularly you don't want to
> dig through the underside with a multimeter to discern which cap blew
> this time.
Ditto. There's only about 6 or 8 wax caps in the set and it would be
advisable to replace them all in one fell swoop unless you want a
forever fixit project. The S-38 series are somewhat easy and decent
little sets to fix up and listen to. No real challenges other than the
cheapo BFO scheme.
-Bill
CW
--
CW
KC7NOD
Web Page http://www.kc7nod.20m.com
"w9gb" <gregor...@attbi.com> wrote in message
news:q8tT8.362605$cQ3.23193@sccrnsc01...
Robert Casey
Matt Senecal wrote:
> My S-38C doesn't seem to be picking any stations up. That is, the
> speaker works, I get a hum when I tune, but where it should be picking
> up stations there's nothing. Even local AM stations that should be
> coming through loud and clear aren't picked up. All the tubes are OK.
Along with the advice from other responders, I would mention that
switches can get dirty and make the set not work. RatShack sells
contact cleaner for this sort of thing.
A hard to read diagram is at:
http://ww3.nostalgiaair.org/schematics/HAL/_HAL_15-59.gif
It's really just an enhanced "All American 5ive" radio.
w9gb
site :-)
http://antiqueradio.org/index.html
73 de w9gb
"CW" <clinton...@attbi.com> wrote in message
news:ixuT8.200736$nZ3.96547@rwcrnsc53...
CW
w9gb
http://antiqueradio.org/safety.htm
"Matt Senecal" <msen...@juno.com> wrote in message
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Kevin T.
switches can get dirty and make the set not work. RatShack sells
contact cleaner for this sort of thing. <<
The S-38C has a "Speaker/Phones" switch, and a "Receive/Stand By"
switch. If either of these two switches is set to the wrong position,
or the switch and/or its associated wiring is faulty, then you will get
no audio.
Also, the S-38C should be sensitive enough to pick up local AM stations
even with no antenna (or ground) connected. And I mean *no* antenna --
not even a typical AM loop or ferrite bar antenna that most other radios
have built-in.
For casual shortwave listening, any member of the Hallicrafters S-38
series makes a very satisfying radio to use, with its excellent sound
quality, powerful audio output, and surprisingly good reception for such
a simple design. I have a S-38C myself and the two things that really
set it apart from modern shortwave receivers is that it has a very low
level of background noise, allowing even very weak signals to be
received without annoying background hiss, and it does not have the
typical tuning distortion that modern ceramic-filter-based receivers
have.
By this I mean when you are tuning across stations on the dial and are
not tuned into the "center" of a signal, the sound will not be
distorted. On a crowded band, the signals smoothly blend into each
other, but it still has good enough selectivity to pick up stations
5 kHz apart from each other.
I have two shortwave "band-scan" recordings made from my S-38C, and I
think they give a very good example of its reception and audio quality.
When I get these files uploaded in MP3 format, they will be available in
this web directory:
starman
How do you know all the tubes are OK? Have you tried substituting each
one with known good ones? I suppose it wouldn't hurt to change all the
paper/wax capacitors but you may still have the same problem after doing
so, if you haven't done some diagnostics first. Do you have the
schematic for making voltage and resistance measurements? If not, try to
find someone with vacuum tube experience.
*****
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Dbowey
S38 get injured. It's a simple set, and unless there's a defective IF
transformer, there can't be much wrong with it.
Don
Matt Senecal
I checked them with my tube tester.
Matt Senecal
> every capacitor.
Glad to hear it! It wouldn't be nearly as much fun if the fix was
simple! :) Would a place like Mouser be a good place to get the caps?
Radio Shack's been getting awfully expensive....
Bob
drifted like a raft in a storm. It was prone to self oscillation and was a
safety hazard.
Use on other than standard broadcast band was difficult. It did fairly well
on that band, however.
The original S-38 had six tubes. The sixth tube, the BFO, was eliminated in
later versions and the BFO function was accomplished by positive feedback
around the IF amplifier.
I had some of those and made a comment back then about the Hallicrafters
slogan. "The radio that amazes the experts." Maybe I was an expert because
I was amazed. Amazed that they could sell such a thing. I believe the
original price was $39.95 but later versions kept going up in price with
little or no change. The most major change was the S-38E that was given a
slide rule dial, similar to the S-53 and the HT-18. It seemed that the only
thing they changed otherwise was the color of the cabinet.
Echophone, a division of Hallicrafters, sold something like an EC-1 I
believe that was essentially the same radio.
73, Bob
w9gb
harder to find parts
w9gb
"Matt Senecal" <msen...@juno.com> wrote in message
news:62bf14a6.02063...@posting.google.com...
Dbowey
original price was $39.95 but later versions kept going up in price with
little or no change. >>
That was about 1 weeks pay for a truck driver in about 1949. As far as
performance, it beat my super-regen in many respects. My neigbor owned one and
loaned it to me often. One thing I had in good measure was antennas - and lots
of space for them with trees in about the right places. With a decent antenna,
the S38C worked well.
Don
Kevin T.
bandspread, and drifted like a raft in a storm. It was prone to self
oscillation and was a safety hazard. <<
My S-38C doesn't seem so bad. With only five tubes, only one of which
provides the audio output, it has enough audio power through its
"Phones" jack to provide room-filling sound from a set of four speakers
that I have normally connected to a 65W/ch stereo system. It picks up
many stations with no antenna at all, and a simple indoor wire antenna
fills up the shortwave bands with activity. And I've never gotten as
much as a tingle from it, as long as I have the power cord plugged in
the right way.
Keep in mind that the S-38C was a *bottom*-of-the-line shortwave
receiver, from *half a century* ago. That it still manages to have
superior reception and audio fidelity compared to today's receivers of
equal selling price is a testament to the quality of its original design
and craftsmanship. Where can you find a $39.95 radio today that is
hand-made in the USA, covers continuously from 520 to 30,000 kHz, and
has a BFO, a lighted bandspread dial, and powerful audio with excellent
fidelity?
And if you'd like to hear some examples of what the Hallicrafters S-38C
can do, including two band-scans and a high fidelity recording of Radio
Exterior de España, fire up your MP3 player and take a listen to the
files at this web site:
Phil Witt
wrote:
>And if you'd like to hear some examples of what the Hallicrafters S-38C
>can do, including two band-scans and a high fidelity recording of Radio
>Exterior de España, fire up your MP3 player and take a listen to the
>files at this web site:
>
>http://rvcc2.raritanval.edu/ktek9053/s38c/
Nice recordings. Makes me want to fire up my regen. Shortwave
broadcast stations don't broadcast in "high fidelity," though.
John Stone
on 6/30/02 2:21 PM:
> Keep in mind that the S-38C was a *bottom*-of-the-line shortwave
> receiver, from *half a century* ago. That it still manages to have
> superior reception and audio fidelity compared to today's receivers of
> equal selling price is a testament to the quality of its original design
> and craftsmanship. Where can you find a $39.95 radio today that is
> hand-made in the USA, covers continuously from 520 to 30,000 kHz, and
> has a BFO, a lighted bandspread dial, and powerful audio with excellent
> fidelity?
$39.95 in 1952 dollars was worth a hell of a lot more than $39.95 in 2002
dollars. As for "powerful audio", it was no more powerful than other AA5
radio on the market; which is to say-maybe a watt and a half, give or take
a watt. Depends on how much distortion you are willing to tolerate. That
said, a watt into efficient speakers can be fairly loud.
CW
radio.
"John Stone" <jms...@attbi.com> wrote in message
news:B944D9B3.1AE2F%jms...@attbi.com...
Kevin T.
cheap radio. <<
Try making a radio today in the USA using hand-assembled wiring and
components (with or without vacuum tubes) and it will likely come out to
cost $270+, regardless if its performance justifies that cost or not.
That is why the Bose WaveRadio is darn expensive ($350+)... it is one of
the last American-made radios.
norm...@pacbell.net
Norm Lehfeldt
"Kevin T." <kevtr...@oohay.com> wrotf:
CW
<norm...@pacbell.net> wrote in message
news:3d1fbe92...@news.sf.sbcglobal.net...
Larry Ozarow
>
> 39.95 in 1952 was about equivalent to 270.00 today. It was not a cheap
> radio.
> --
> CW
> KC7NOD
> Web Page http://www.kc7nod.20m.com
Well, it wasn't cheap, but as far as shortwave sets went it was a
cheap radio. Straight currency translations don't always tell
the whole story, since people had to pay a heck of a lot more
for their electronic gizmos back then. A basic 9 tube "communications
receiver" from Hallicrafters or National went for well over $100, as
did a Trans Oceanic, which was itself a 5 tube radio. Certainly
the 9 tube sets and the Zeniths were much better radios, but at as
much as three times the price they better have been.
Oz
Kevin T.
but at as much as three times the price they better have been. <<
And today we have come full circle. You can spend $1000 on a stereo
system whose AM tuner sounds like crap and picks up maybe 2 or 3
stations on the whole dial, or you can spend $10 on a cheap pocket radio
whose AM tuner sounds great and has the dial filled with stations,
especially at night.
For example, try the Radio Shack "Pocket Size AM Radio", for a whopping
$6.99. It is probably the cheapest new radio you can buy anywhere, and
yet it has darn good reception and sound quality that would make most
stereo systems costing 10 or 100 times as much jealous.
Stephen C. Robbins
"Kevin T." <kevtr...@oohay.com> wrote in message
news:3D1FBD...@oohay.com...
> That is why the Bose WaveRadio is darn expensive ($350+)... it is one of
> the last American-made radios.
Dead wrong Kevin. The crew at The Mountain created the WaveRadio with
marketing as the primary basis for design. It was to be a quality product,
cheap to manufacture, that could generate sales directly proportional to the
budget spent on marketing campaigns which placed the product in a targeted
market.
The marketing crew did a great job. They have created the image which has
no basis in reality. It is an awesome feat to sell several hundred $50
radios for $600+ . You achieve the same profit as if you sold thousands
at their true $50 value BUT do not have to maintain as large a manufacturing
base (buildings, people, facilities mountainous, etc). You can scale your
profits by marketing more... another TV infomercial, another ad in a yuppie
magazine, etc etc......
As far as "American Made" goes, Bose doesn't emphasize that since it has no
marketing value. (Think BMW, Lexis, Gucci, Mercedes, Browning, Movado, etc
etc)
The Bose WeveRadio is an OK radio but I laugh at the suckers who pay to buy
into the marketing hype and I sit in awe of the marketing machine that
pulled off commercialization of this product.
Steve
cashaw
Stephen C. Robbins wrote in message <3d2052a4$1...@news.netacc.net>...
>
>"Kevin T." <kevtr...@oohay.com> wrote in message
>news:3D1FBD...@oohay.com...
>> That is why the Bose WaveRadio is darn expensive ($350+)... it is one of
>> the last American-made radios.
>
The marketing of the Waveradio is impressive, they are advertised in the
British Press as a luxury, must have item and they did semi-convince me that
I really needed a Waveradio as part of my collection. I was therefore
disappointed when I ran across one in person in a shop in Sweden. OK, I
didn't have chance to listen to it but looking at the rather 'plasticky'
build quality and the rubber control buttons it felt looked a bit cheap.
It certainly didn't make me wish to open my wallet there and then. OK, a
radio is in the listening, I know, but I certainly hope the sound far
exceeds it's image in build quality.
William Sommerwerck
kindly.
Basically, it's sonic crap.
A KLH Model Eight or Model 21 table radio provides a much more-pleasing
listening experience, despite the fact that neither is stereo. Heck, the
speakers in the Wave are so close together, you have to bend over and stick your
head next to the unit to even begin to hear stereo.
The Wave has one and only one advantage -- it's a single-piece unit. If you
don't mind larger speakers and the some cable clutter, you can do much, much,
much better for a lot less money.
I have a Monsoon M-1000 speaker/amp system attached to my computer. It cost less
than $200, and the sound is far superior to the Bose's. I bought a used Sony
D-T66 Discman for $20, and plugged it into the Monsoon's second input for CD
playback and stereo FM.
If I ever get the KLH Model 13 Multiplex Adapter realigned, I just might replace
the Monsoon with the adapter and a Model Eight. Now, that would be a fun system!
Pete Gianakopoulos
function of the low system gain of the S-38C. Granted, you don't need any
better than a 12dB noise figure to hear anything on shortwave, given a
fairly good antenna, but it never hurts to have that extra gain, so you
don't have to turn up the volume on very weak signals. Now, as far as that
comment about ceramic filters..........................I have been using
them in my own designs for several years, and the distortion on my receivers
from antenna input to speaker output is less than .5%.
In all fairness to you, Kevin, that distortion phenomenum with ceramic
filters that you are talking about is a result of those filters not being
terminated properly. Correctly terminated, you should have less than 1dB of
passband ripple.
That S-38 is a pretty cool receiver though!
Pete KE9OA
Kevin T. <kevtr...@oohay.com> wrote in message
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Ian Smith
I hear you on this one. You don't always get what you pay
for. I once owned one of those $1000 stereo with a deaf front
end on AM and FM. Now make do with cheap radio connected to
cheap computer speakers (with amp and subwoofer built in). Good
sound. Works for me!
========================================
= Ian Smith, Colorado Springs. =
= 38.7977°N, 104.7452°W, alt.1830m =
= ianinbun...@earthlink.net =
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