Reviving 50+ year old Wire Recorder

[Chris Cooper]

My father has "bestowed" upon me the old family wire recorder, a Silvertone
Model 8170. He claims that the last time he ran it (a year or two ago) it
worked for a while and then smoke came out of it.

And now I have it.

I opened it up, blew all the dust out, reseated the tubes, plugged it in,
and it ran fine - except that the only sound out of the speaker was a strong
60 Hz hum.

For $20 I've ordered replacement tubes for it, seems like that's got a good
chance of solving the problem.

If not, do people have suggestions on how to "debug" this problem? I've got
an old oscillscope I can use.

It's got a schematic printed on the bottom of the case, but only about half
the schematic remains, and it's the half dealing with the microphone and
phono input, not the speaker output.

The only idea I have, is to take beast apart even more, and try to re-create
the schematic, or at least the speaker amplifier portion.

And then the next question - if I get this thing working (or even if I
don't), is there anything reasonable to do with it? It has some mild
sentimental value, not much, on eBay some of these are going for a whopping
$10, are there museums that might be interested in such a piece?

Thanks all!
Chris

 

[James Sweet]

"Chris Cooper" <chrisnews@sc3.net> wrote in message
news:3faed79f$0$200$75868355@news.frii.net...

My father has "bestowed" upon me the old family wire recorder, a
Silvertone
Model 8170. He claims that the last time he ran it (a year or two ago) it
worked for a while and then smoke came out of it.

And now I have it.

I opened it up, blew all the dust out, reseated the tubes, plugged it in,
and it ran fine - except that the only sound out of the speaker was a
strong
60 Hz hum.

For $20 I've ordered replacement tubes for it, seems like that's got a
good
chance of solving the problem.

If not, do people have suggestions on how to "debug" this problem? I've
got
an old oscillscope I can use.

It's got a schematic printed on the bottom of the case, but only about
half
the schematic remains, and it's the half dealing with the microphone and
phono input, not the speaker output.

The only idea I have, is to take beast apart even more, and try to
re-create
the schematic, or at least the speaker amplifier portion.

And then the next question - if I get this thing working (or even if I
don't), is there anything reasonable to do with it? It has some mild
sentimental value, not much, on eBay some of these are going for a
whopping
$10, are there museums that might be interested in such a piece?

Thanks all!
Chris

The tubes are probably fine, you have some audio and tubes rarely just fail
unless the heater burns out, usually they gradually get weak. Any
electrolytic capacitors are likely dried out and will need to be replaced,
switches should be cleaned, and everything carefully inspected.

 

[Frank Dresser]

"Chris Cooper" <chrisnews@sc3.net> wrote in message
news:3faed79f$0$200$75868355@news.frii.net...

My father has "bestowed" upon me the old family wire recorder, a
Silvertone
Model 8170. He claims that the last time he ran it (a year or two
ago) it
worked for a while and then smoke came out of it.

[snip]

You can also ask on rec.antiques.radio+phono. Wire recorders are
discussed from time to time.

Frank Dresser

 

[Eric Vey]

If smoke came out, you should see some charring.

"Chris Cooper" <chrisnews@sc3.net> wrote in message
news:3faed79f$0$200$75868355@news.frii.net...

My father has "bestowed" upon me the old family wire recorder, a
Silvertone
Model 8170. He claims that the last time he ran it (a year or two
ago) it
worked for a while and then smoke came out of it.

And now I have it.

I opened it up, blew all the dust out, reseated the tubes, plugged it
in,
and it ran fine - except that the only sound out of the speaker was a
strong
60 Hz hum.

For $20 I've ordered replacement tubes for it, seems like that's got a
good
chance of solving the problem.

If not, do people have suggestions on how to "debug" this problem?
I've got
an old oscillscope I can use.

It's got a schematic printed on the bottom of the case, but only about
half
the schematic remains, and it's the half dealing with the microphone
and
phono input, not the speaker output.

The only idea I have, is to take beast apart even more, and try to
re-create
the schematic, or at least the speaker amplifier portion.

And then the next question - if I get this thing working (or even if I
don't), is there anything reasonable to do with it? It has some mild
sentimental value, not much, on eBay some of these are going for a
whopping
$10, are there museums that might be interested in such a piece?

Thanks all!
Chris

 

[Ken Taylor]

I'd actually suspect filter cap('s) in the power supply, or if it happens to
use selenium rectifier(s) in the ps, then those.

Ken

"Eric Vey" <junk@ericvey.com> wrote in message
news:bomv4v$1gptqh$1@ID-61706.news.uni-berlin.de...

If smoke came out, you should see some charring.

"Chris Cooper" <chrisnews@sc3.net> wrote in message
news:3faed79f$0$200$75868355@news.frii.net...
My father has "bestowed" upon me the old family wire recorder, a
Silvertone
Model 8170. He claims that the last time he ran it (a year or two
ago) it
worked for a while and then smoke came out of it.

And now I have it.

I opened it up, blew all the dust out, reseated the tubes, plugged it
in,
and it ran fine - except that the only sound out of the speaker was a
strong
60 Hz hum.

For $20 I've ordered replacement tubes for it, seems like that's got a
good
chance of solving the problem.

If not, do people have suggestions on how to "debug" this problem?
I've got
an old oscillscope I can use.

It's got a schematic printed on the bottom of the case, but only about
half
the schematic remains, and it's the half dealing with the microphone
and
phono input, not the speaker output.

The only idea I have, is to take beast apart even more, and try to
re-create
the schematic, or at least the speaker amplifier portion.

And then the next question - if I get this thing working (or even if I
don't), is there anything reasonable to do with it? It has some mild
sentimental value, not much, on eBay some of these are going for a
whopping
$10, are there museums that might be interested in such a piece?

Thanks all!
Chris

 

[GPG]

"Ken Taylor" <ken123@xtra.co.nz> wrote in message news:<gIDrb.14005$Mn.346734@news.xtra.co.nz>...

I'd actually suspect filter cap('s) in the power supply, or if it happens to
use selenium rectifier(s) in the ps, then those.

Selenium rectifiers make a very distinctive smell when they fail

 

[Sam Goldwasser]

"Eric Vey" <junk@ericvey.com> writes:

If smoke came out, you should see some charring.

Or dripping if the filter cap.

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Important: The email address in this message header may no longer work. To
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[James Sweet]

"GPG" <peg@slingshot.co.nz> wrote in message
news:62069f15.0311100429.5635e55c@posting.google.com...

"Ken Taylor" <ken123@xtra.co.nz> wrote in message
news:<gIDrb.14005$Mn.346734@news.xtra.co.nz>...
I'd actually suspect filter cap('s) in the power supply, or if it
happens to
use selenium rectifier(s) in the ps, then those.

Selenium rectifiers make a very distinctive smell when they fail

Blech! Yeah they do! Is there anything that smells more horrible?

 

[Roy J. Tellason]

GPG wrote:

"Ken Taylor" <ken123@xtra.co.nz> wrote in message
news:<gIDrb.14005$Mn.346734@news.xtra.co.nz>...
I'd actually suspect filter cap('s) in the power supply, or if it happens
to use selenium rectifier(s) in the ps, then those.

Selenium rectifiers make a very distinctive smell when they fail

Oh yeah! If you've ever smoked one of these there's no way you're *ever*
going to forget that smell...

I wonder how many of you guys have worked on stuff that uses these?

 

[Jason D.]

On 10 Nov 2003 08:21:32 -0500, Sam Goldwasser <sam@saul.cis.upenn.edu>
wrote:

"Eric Vey" <junk@ericvey.com> writes:

If smoke came out, you should see some charring.

Or dripping if the filter cap.

What about those aka stinky rotten fish cans (caps) when soldering?
This made me really go oooh! snorting & hands waving trying to get
stink out of my nose every time. Is this like that for smoking
selenium rectifiers? Yes I did seen them but not ones that blew.

What about the blue disk caps that let out pall of BIG thick pink
smoke, somewhat stinky?

Cheers,

Wizard

 

[Robert Baer]

Chris Cooper wrote:

My father has "bestowed" upon me the old family wire recorder, a Silvertone
Model 8170. He claims that the last time he ran it (a year or two ago) it
worked for a while and then smoke came out of it.

And now I have it.

I opened it up, blew all the dust out, reseated the tubes, plugged it in,
and it ran fine - except that the only sound out of the speaker was a strong
60 Hz hum.

For $20 I've ordered replacement tubes for it, seems like that's got a good
chance of solving the problem.

If not, do people have suggestions on how to "debug" this problem? I've got
an old oscillscope I can use.

It's got a schematic printed on the bottom of the case, but only about half
the schematic remains, and it's the half dealing with the microphone and
phono input, not the speaker output.

The only idea I have, is to take beast apart even more, and try to re-create
the schematic, or at least the speaker amplifier portion.

And then the next question - if I get this thing working (or even if I
don't), is there anything reasonable to do with it? It has some mild
sentimental value, not much, on eBay some of these are going for a whopping
$10, are there museums that might be interested in such a piece?

Thanks all!
Chris

Old tube circuits should be powered up slowly with a variac, so that
the electrolytics have a chance to reform.
Failing that, all electrolytics should be replaced before power on, as
it is extremely likely they are bad; that is why you heard hum. New
tubes will not fix that.
My questions are (1) do the e-bay recorders *work*, (2) are those you
found actually wire recorders?, (3) if they had been repaired, were as
orginal parts as possible used? (4) case, panel, knobs, etc in
semi-pristine condition?
I dare say *no* to most of that criteria.
You have a possible collectible, and the better the condition, and
original-type parts for repair used, the higher the value.
Oh, yes i forgot - any wire spools for recording? And what is recorded
on those you have? Any documented provenance concerning those recordings
(historical interest).

 

[Roy J. Tellason]

Robert Baer wrote:

Old tube circuits should be powered up slowly with a variac, so that
the electrolytics have a chance to reform.

Yeah, *real* slowly, if you have the patience for that. And they may end up
turning out to not be any good anyway...

Failing that, all electrolytics should be replaced before power on, as
it is extremely likely they are bad; that is why you heard hum. New
tubes will not fix that.

Right.

My questions are (1) do the e-bay recorders *work*, (2) are those you
found actually wire recorders?, (3) if they had been repaired, were as
orginal parts as possible used? (4) case, panel, knobs, etc in
semi-pristine condition?

That "original parts" bit got my attention.

I dare say *no* to most of that criteria.
You have a possible collectible, and the better the condition, and
original-type parts for repair used, the higher the value.

How can you even *get* "original-type parts" for a lot of this stuff? And why
would you want to, assuming that you wanted something to work?

Going back a couple of decades, I spent some time helping a guy get a number
of antique radios working. He was interested in anything that wasn't
plastic, most of it going back to WWII or before. I'd take the guts out and
work 'em over, get it working well.

For electrolytics a number of those sets had cans that had a *big* nut going
around a threaded bushing. I'd never seen those prior to working with those
sets. At that time, I had a few of those mounting plates for the twist-tab
type cans (and probably still have a couple) and I ended up drilling screw
holes, putting one of those in, and putting a twist-tab can in there.
These days I'm not sure those are even available.

And those old wax-coated paper caps! I always end up yanking them out and
replacing them with mylar types. There's little likelihood of them still all
being good after all those years.

Now, assuming that you could even _find_ original-type parts for these
things, would you really want to use them? Seems to me that would be just
asking for trouble...

 

[Ian]

On Tue, 11 Nov 2003 00:22:06 GMT, jpero@sympatico.ca (Jason D.) wrote:

On 10 Nov 2003 08:21:32 -0500, Sam Goldwasser <sam@saul.cis.upenn.edu
wrote:

"Eric Vey" <junk@ericvey.com> writes:

If smoke came out, you should see some charring.

Or dripping if the filter cap.


What about those aka stinky rotten fish cans (caps) when soldering?
This made me really go oooh! snorting & hands waving trying to get
stink out of my nose every time. Is this like that for smoking
selenium rectifiers? Yes I did seen them but not ones that blew.

Be very careful about the smoke from selenium rectifiers it's quite
toxic

 

[Robert Baer]

"Roy J. Tellason" wrote:

Robert Baer wrote:

Old tube circuits should be powered up slowly with a variac, so that
the electrolytics have a chance to reform.

Yeah, *real* slowly, if you have the patience for that. And they may end up
turning out to not be any good anyway...
Absolutely correct!

Failing that, all electrolytics should be replaced before power on, as
it is extremely likely they are bad; that is why you heard hum. New
tubes will not fix that.

Right.

My questions are (1) do the e-bay recorders *work*, (2) are those you
found actually wire recorders?, (3) if they had been repaired, were as
orginal parts as possible used? (4) case, panel, knobs, etc in
semi-pristine condition?

That "original parts" bit got my attention.

I dare say *no* to most of that criteria.
You have a possible collectible, and the better the condition, and
original-type parts for repair used, the higher the value.

How can you even *get* "original-type parts" for a lot of this stuff? And why
would you want to, assuming that you wanted something to work?
There is a *BIG* difference between -just- getting an old tube based

unit to work,
and *restoring* it. No antique dealer will pay thousands for an old
Model A Ford that
was just fixed!

Going back a couple of decades, I spent some time helping a guy get a number
of antique radios working. He was interested in anything that wasn't
plastic, most of it going back to WWII or before. I'd take the guts out and
work 'em over, get it working well.

For electrolytics a number of those sets had cans that had a *big* nut going
around a threaded bushing. I'd never seen those prior to working with those
sets. At that time, I had a few of those mounting plates for the twist-tab
type cans (and probably still have a couple) and I ended up drilling screw
holes, putting one of those in, and putting a twist-tab can in there.
These days I'm not sure those are even available.
I looked a few years ago and found that the twis-tab types were

avaialble then.
Concerning making something look authentic, i have put minature
electrolytics
inside those cans that you speak of - but only after approval of the
collector.
Heck, i have been able to rejuvenate the 20's type liquid
electrolytics - thereby
extending their life into the 70's (at least).

And those old wax-coated paper caps! I always end up yanking them out and
replacing them with mylar types. There's little likelihood of them still all
being good after all those years.
You are speaking of the oil impregnated paper capacitors where wax was

typically
used for the outer seal.
I have tested many hundreds of them and found only one bad unit.
The worst capacitors were the so-called "black beauty" which had a
plastic outer
covering and was an oil impregnated paper capacitor inside.
They typically leaked - !oil! and lost capacitance and made a damn
mess to clean up.

Now, assuming that you could even _find_ original-type parts for these
things, would you really want to use them? Seems to me that would be just
asking for trouble...
Up to the 80s, a large amount of the obsolete components in 20s and

30s radios
were available new, and some could be visually "faked" (namely the
chassis-mount
electrolytics) or rejuvenated (liquid electrolytics) or replaced with
NOS (resistors)
where the most discriminating collector demanded authenticity.

These daze, it is hard to find high voltage parts and/or high power
parts that were common
in the 80s to early 90s.

 

[Ken Taylor]

"Roy J. Tellason" <rtellason@DONTSPAM MEblazenet.net> wrote in message
news:vr039p8r2g6v68@corp.supernews.com...

GPG wrote:

"Ken Taylor" <ken123@xtra.co.nz> wrote in message
news:<gIDrb.14005$Mn.346734@news.xtra.co.nz>...
I'd actually suspect filter cap('s) in the power supply, or if it
happens
to use selenium rectifier(s) in the ps, then those.

Selenium rectifiers make a very distinctive smell when they fail

Oh yeah! If you've ever smoked one of these there's no way you're *ever*
going to forget that smell...

I wonder how many of you guys have worked on stuff that uses these?

I'm well aware of that smell too! The OP may not have been though, so

a reference to the pungent odour (which he hadn't smelt anyway) wouldn't
have helped.

Ken

 

[Frank Dresser]

"Robert Baer" <robertbaer@earthlink.net> wrote in message
news:3FB1474D.B4CE4E9B@earthlink.net...

You are speaking of the oil impregnated paper capacitors where wax
was
typically
used for the outer seal.
I have tested many hundreds of them and found only one bad unit.

Don't you mean only one good one?

The worst capacitors were the so-called "black beauty" which had a
plastic outer
covering and was an oil impregnated paper capacitor inside.
They typically leaked - !oil! and lost capacitance and made a damn
mess to clean up.


Up to the 80s, a large amount of the obsolete components in 20s and
30s radios
were available new, and some could be visually "faked" (namely the
chassis-mount
electrolytics) or rejuvenated (liquid electrolytics) or replaced with
NOS (resistors)
where the most discriminating collector demanded authenticity.

These daze, it is hard to find high voltage parts and/or high power
parts that were common
in the 80s to early 90s.

Digi-Key and Mouser both have a good selection of film caps up to 600V
and electrolytics to 450V. I'm sure Digi-Key has film caps up to 1600V
and it think Mouser has them. Other vendors should have them, as well.
Same with high power resistors.

There's several smaller vendors who sell such parts to hobbyists at a
good price:

http://www.radioantiques.com/supplies.html

Bob is one of the vendors who sells high voltage capacitor lots on
e-bay.

I've used alot of those yellow axial lead mylars, and I think they're a
great deal.

Frank Dresser

 

[Roy J. Tellason]

Frank Dresser wrote:

You are speaking of the oil impregnated paper capacitors where wax was
typically used for the outer seal.
I have tested many hundreds of them and found only one bad unit.

Don't you mean only one good one?

 

[Rich Grise]

James Sweet wrote:

"GPG" <peg@slingshot.co.nz> wrote in message
news:62069f15.0311100429.5635e55c@posting.google.com...
"Ken Taylor" <ken123@xtra.co.nz> wrote in message
news:<gIDrb.14005$Mn.346734@news.xtra.co.nz>...
I'd actually suspect filter cap('s) in the power supply, or if it
happens to
use selenium rectifier(s) in the ps, then those.

Selenium rectifiers make a very distinctive smell when they fail

Blech! Yeah they do! Is there anything that smells more horrible?

Yes. When they fail inside a sealed, pressurized power supply housing,
and the dimwit pilot or EWO leaves it on for the whole mission (i.e.,
continuing to burn), and you open the power supply case in the shop.

It clears the room. (how do you do a yucchy-face with punct. marks?)

Cheers!
Rich

 

[Dennis Davis]

Chris Cooper wrote:

My father has "bestowed" upon me the old family wire recorder, a
Silvertone
Model 8170. He claims that the last time he ran it (a year or two ago) it
worked for a while and then smoke came out of it.

And now I have it.

I opened it up, blew all the dust out, reseated the tubes, plugged it in,
and it ran fine - except that the only sound out of the speaker was a
strong 60 Hz hum.

For $20 I've ordered replacement tubes for it, seems like that's got a
good chance of solving the problem.

If not, do people have suggestions on how to "debug" this problem? I've
got an old oscillscope I can use.

It's got a schematic printed on the bottom of the case, but only about
half the schematic remains, and it's the half dealing with the microphone
and phono input, not the speaker output.

The only idea I have, is to take beast apart even more, and try to
re-create the schematic, or at least the speaker amplifier portion.

And then the next question - if I get this thing working (or even if I
don't), is there anything reasonable to do with it? It has some mild
sentimental value, not much, on eBay some of these are going for a
whopping $10, are there museums that might be interested in such a piece?

Thanks all!
Chris
sounds like a paper capacitor smoked, could of caused a resistor or 2 to

burn as well,replace all the paper caps and check for bad resistors. a
schematic probably will be nessasary as the values on the parts will be
hard to read,might get lucky with schematic if its on inside of the cover.
the tubes are also a good idea, most are probably weak and in need of
replacement.

 

[N. Thornton]

Chris Cooper wrote:

My father has "bestowed" upon me the old family wire recorder, a
Silvertone
Model 8170. He claims that the last time he ran it (a year or two ago) it
worked for a while and then smoke came out of it.

And now I have it.

I opened it up, blew all the dust out, reseated the tubes, plugged it in,
and it ran fine - except that the only sound out of the speaker was a
strong 60 Hz hum.

For $20 I've ordered replacement tubes for it, seems like that's got a
good chance of solving the problem.

If not, do people have suggestions on how to "debug" this problem? I've
got an old oscillscope I can use.

It's got a schematic printed on the bottom of the case, but only about
half the schematic remains, and it's the half dealing with the microphone
and phono input, not the speaker output.

The only idea I have, is to take beast apart even more, and try to
re-create the schematic, or at least the speaker amplifier portion.

And then the next question - if I get this thing working (or even if I
don't), is there anything reasonable to do with it? It has some mild
sentimental value, not much, on eBay some of these are going for a
whopping $10, are there museums that might be interested in such a piece?

Thanks all!
Chris

Hi. Sounds probably like a bad capacitor, or possibly a dud connection
on the input end of the audio chain. I'm not sure if youve got the
knowledge to do it but we can see.

Forget new valves, keep the old ones in there if poss. And keep the
scope off it as you may make the scope case live and get electrocuted.
Place to start is work out which valve does what, and try the unit
with different valves pulled out to locate the problem area.

Next move would be to replace any bad caps. But since this is a
valuable museum piece I wouldnt replace them, I'd open the caps up,
fit well rated modern ones inside and reseal exactly as per original.
And only on caps that test bad.

Dont dismantle unless you know what youre doing. Live voltages may
appear where you least expect them, eg on heads, knob spindles,
chassis, and stored in reservoir caps when the things unlpugged. I
would do as assessment of its safety before plugging it in, theres
some truly stuipid stuff around from back then.

Really though I'd give it to a specialist to assess if possible.


Regards, NT