Re: Sprague capacitors variants

#30083

Copy the URL then go to the wayback machine and enter the copied address.? Click on the most current save then open the address.

Jim

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

On Thursday, May 2, 2024 at 01:00:10 AM CDT, Richard Knoppow <1oldlens1@...> wrote:

Can't get this to load. Tried both Firefox and Edge

Show quoted text

On 5/1/2024 7:57 PM, wekemp@... wrote:

There is a most interesting online document written by a Jesse Acorn
about “Vintage Tubular Capacitors: Paper or Polymer?” at

<>.

Included is a table of 200 capacitor types by manufacturer with the
physical/dielectric parameters. He lists eight types of Sprague Black
Beauty capacitors. Also of note is any capacitors he had identified as
containing PCB oils are highlighted in Red letters (none of which were
Sprague).

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

Re: Sprague capacitors variants

#30082

Can't get this to load. Tried both Firefox and Edge

Show quoted text

On 5/1/2024 7:57 PM, wekemp@... wrote:

There is a most interesting online document written by a Jesse Acorn
about “Vintage Tubular Capacitors: Paper or Polymer?” at

<>.

Included is a table of 200 capacitor types by manufacturer with the
physical/dielectric parameters. He lists eight types of Sprague Black
Beauty capacitors. Also of note is any capacitors he had identified as
containing PCB oils are highlighted in Red letters (none of which were
Sprague).

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

Re: Sprague capacitors variants

#30081

Very nice, thank you!

Regards,

Jim

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

On Wednesday, May 1, 2024 at 09:57:44 PM CDT, wekemp@... <wekemp@...> wrote:

There is a most interesting online document written by a Jesse Acorn about “Vintage Tubular Capacitors: Paper or Polymer?” at .

Included is a table of 200 capacitor types by manufacturer with the physical/dielectric parameters. He lists eight types of Sprague Black Beauty capacitors. Also of note is any capacitors he had identified as containing PCB oils are highlighted in Red letters (none of which were Sprague).

Re: Sprague capacitors variants

#30080

There is a most interesting online document written by a Jesse Acorn about “Vintage Tubular Capacitors: Paper or Polymer?” at .

Included is a table of 200 capacitor types by manufacturer with the physical/dielectric parameters. He lists eight types of Sprague Black Beauty capacitors. Also of note is any capacitors he had identified as containing PCB oils are highlighted in Red letters (none of which were Sprague).

Re: Sprague capacitors variants

#30079
Edited

开云体育

Re signatures

A long time back this is how I managed to get an auto signature. That signature box was not obvious to me when it was empty, so maybe others have the same problem… image here:

?

Show quoted text

From: [email protected] [mailto:[email protected]] On Behalf Of Jacques_VE2JFE
Sent: Wednesday, May 1, 2024 11:16 AM
To: [email protected]
Subject: Re: [HallicraftersRadios] Sprague capacitors variants

?

Hi ”?Wekemp” (it can be good that you sign your postings, btw…)

?

--
don??? va3drl

Re: Sprague capacitors variants

#30078

Not to complicate matters but Bakelite is manufactured with both heat and pressure.? The maximum heat needed is well above that needed to boil water, typically about 150 deg C or 302 deg F per the Wikipedia article on compression molding.? The pressure is needed to prevent foaming of the uncured Bakelite.? The presence of water does not interferer with the manufacturing process but evidently prevents the uncured Bakelite from seeping into the rolled capacitor layers.

Regards,

Jim

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

On Wednesday, May 1, 2024 at 09:33:34 AM CDT, wekemp@... <wekemp@...> wrote:

Interesting stuff and thoughts on Sprague Caps.

My comment on the report about the water removal from inside Sprague Black Beauty caps as being “boiled” out of the capacitor body after molding as mentioned by Jacques. This suggests the capacitors may have been heated to a high temperature to remove the water. However more likely the water was “vaporized” from the capacitor body by the reduced pressure and not so much by heating. Don’t know how low the vacuum was that Sprague used to “boil” or “vaporize” water but at room temperature of say 72 degrees Fahrenheit water boils at 0.4 psia which is a relatively high vacuum but not difficult to obtain with your ordinary laboratory vacuum pump from a small volume like that inside a capacitor.

An observation from the Jan 1948 issue of Radio Maintenance magazine that don Root earlier referenced. On page 31, a company named “Sangamo Electric Company” in Springfield, IL advertised that “the first plastic tubular paper capacitor was introduced by Sangamo in 1946.” They improved on their product and their “new” paper tubular Type 30 capacitors were molded in “thermo-setting plastic”, which was probably Bakelite. So apparently Sangamo produced molded paper capacitors a little before Sprague using similar technology.

Anybody ever hear of Sangamo? At one time, Sangamo Electric Co. was a substantial manufacturer in the US. They made electrical meters, sonar and radio equipment during WWII as well as other items such as molded and electrolytic capacitors from the 1890s until 1978. An online article about rebuilding the esteemed Collins R390A mentions that Sangamo molded caps were used in the receivers built in the 1950s as well as caps made by Sprague.

From “Service” magazine, May 1947, page 38: “A paper tubular capacitor molded in thermo-setting plastic has been announced by the Sangamo Electric Company, Springfield, Illinois. These new capacitors are designated as type 30 and are offered in halo wax impregnated, in tan, and diaclor impregnated, in red.”

Note, “Diaclor” is a polycholorbyiphenlyl or PCB oil no longer used in electrical components for its alleged highly carcinogenic properties and banned by the US EPA in 1979. Sangano was listed in US EPA documents as using Diaclor in their capacitors. Sprague was also named in the EPA documents on capacitors for using a similar PCB material called “Clorinol”. So Clorinol is perhaps the type of oil Sprague used in their Black Beauty molded capacitors. For those guys who like to open up Black Beauty caps for examination, you might want to wash your hands afterwards.

Re: SX-101 MK 3 Basic Questions

#30077

Hello:
It has been forever, a few more projects jumped ahead of the SX101 MK3.
Question about the 50.5Khz alignment.
Is the HP-651B Signal Generator suitable for this job ?
Also have an HP-8640B but does not tune low enough.
Any advice on how to approach the alignment appreciated.
My email is CRY42@....
Thanks
Charles

Re: Sprague capacitors variants

#30076

开云体育

Hi ”?Wekemp” (it can be good that you sign your postings, btw…)

?

I did not suggested that the Sprague caps were heated after the phenolic molding process.

Only the pressure drop was enable to do this, but whatever we call it boiling or vaporisation, it turns out to be the same.

Some made instant “freeze dried” coffee with a similar process, right ?

My real concern is if Sprague really used the described manufacturing process, how they were able to make sure that no traces of moisture (or oxygen for that matter), remained inside the capacitor structure before the introduction of the oil ?

AFAIR, the old Sangamo caps were molded in blue polystyrene plastic.

Same kind of plastic for the brown British Hunts.

?

Thanks for the warnings about the PCB oils.

?

73, Jacques, VE2JFE in Montreal

Re: Sprague capacitors variants

#30075

开云体育

>”Anybody ever hear of Sangamo?”

Yes, producer of some of the industry’s worst electrolytic capacitors.? During college, I was the Chief Engineer for our local AM/FM broadcast stations.? ?The FM station’s control room console was a Rockwell/Collins Mark 8 and it used a sizable number of Sangamo caps in the power supply.? After several failures in a short time period, I switched to the equivalent Sprague ‘lytic caps and had no further difficulties.?

Paul, W9AC

Re: Sprague capacitors variants

#30074

Interesting stuff and thoughts on Sprague Caps.

My comment on the report about the water removal from inside Sprague Black Beauty caps as being “boiled” out of the capacitor body after molding as mentioned by Jacques. This suggests the capacitors may have been heated to a high temperature to remove the water. However more likely the water was “vaporized” from the capacitor body by the reduced pressure and not so much by heating. Don’t know how low the vacuum was that Sprague used to “boil” or “vaporize” water but at room temperature of say 72 degrees Fahrenheit water boils at 0.4 psia which is a relatively high vacuum but not difficult to obtain with your ordinary laboratory vacuum pump from a small volume like that inside a capacitor.

An observation from the Jan 1948 issue of Radio Maintenance magazine that don Root earlier referenced. On page 31, a company named “Sangamo Electric Company” in Springfield, IL advertised that “the first plastic tubular paper capacitor was introduced by Sangamo in 1946.” They improved on their product and their “new” paper tubular Type 30 capacitors were molded in “thermo-setting plastic”, which was probably Bakelite. So apparently Sangamo produced molded paper capacitors a little before Sprague using similar technology.

Anybody ever hear of Sangamo? At one time, Sangamo Electric Co. was a substantial manufacturer in the US. They made electrical meters, sonar and radio equipment during WWII as well as other items such as molded and electrolytic capacitors from the 1890s until 1978. An online article about rebuilding the esteemed Collins R390A mentions that Sangamo molded caps were used in the receivers built in the 1950s as well as caps made by Sprague.

From “Service” magazine, May 1947, page 38: “A paper tubular capacitor molded in thermo-setting plastic has been announced by the Sangamo Electric Company, Springfield, Illinois. These new capacitors are designated as type 30 and are offered in halo wax impregnated, in tan, and diaclor impregnated, in red.”

Note, “Diaclor” is a polycholorbyiphenlyl or PCB oil no longer used in electrical components for its alleged highly carcinogenic properties and banned by the US EPA in 1979. Sangano was listed in US EPA documents as using Diaclor in their capacitors. Sprague was also named in the EPA documents on capacitors for using a similar PCB material called “Clorinol”. So Clorinol is perhaps the type of oil Sprague used in their Black Beauty molded capacitors. For those guys who like to open up Black Beauty caps for examination, you might want to wash your hands afterwards.

Re: SX100 Sensitivity Pot replacement

#30073

Thank you so much. Thats exactly what I need. This is not a wire wound version. Going to stay with what was installed.?

Re: Sprague capacitors variants

#30072

It could explain why the windings of the caps I took apart were so
distorted. Steam pressure. Why did they do this? Perhaps to leave a void
for the oil. By eyelet I think they mean the hollow tube at one end.
This is connected to the foil on one end and allows both the moisture to
escape and the oil to enter. It is sealed by soldering a lead into it. I
always thought that the caps failed because too much heat was applied to
the lead on that end allowing the solder to melt out and the oil to
escape. However, that does not explain the mutilated windings. The
process of creating pressure during molding to create a void for the oil
could well explain it. I am sure the answer was in the engineering
records at Sprague but the chances they have survived is virtually zero.
I have dissected other failed caps but never saw any others with the
mashed up windings in the BB's.
I wonder how the world these escaped the QC at Sprague. Mashing the
winding must have affected the value if nothing else. Very strange, I
think we don't know the whole story yet.
I was also involved with audio professionally when my hearing was
still good. It is a great frustration to me that I am now deaf and can
no longer judge audio quality. There is probably more misinformation and
myth in audio than anywhere else beyond politics.
BTW, I may have mentioned that I have recently had surgery to place
a cochlear implant. Its too soon to know if it is going to work. If it
restores my hearing enough so that I can carry out a conversation and
use the telephone again I will be satisfied. It takes months and many
adjustments to make it work. At the moment I am no further ahead than I
was before the surgery. Well, I go in again on Friday and hope for the
best.
FWIW, the guitar amp folks WANT distortion, I was always working to
eliminate it. Its the difference between being a sound _producer_ and a
_reproducer_.

Show quoted text

On 4/30/2024 8:20 PM, Jacques_VE2JFE wrote:

Hi all,

Following the address provided by Richard, I read, then downloaded the
article and edited it before conversion in a .pdf.

See attached.

What scares me the most in it is the description of the manufacturing
process for the “Bumblebees”:

/Construction Details (eyelet variation):///

/Eyelet was soldered to a wound foil and left sticking out of the
Bakelite phenolic case during the molding process./

/_Paper and foil slug is soaked with water_//before casing in the
Bakelite to give the slug extra body and prevent the high pressure of
the casting process from distorting the capacitor./

/_After the slug is encased in Bakelite, it is placed in a vacuum oven
where moisture is allowed to escape through the eyelet_//./

/Oil is then introduced into the vacuum chamber and pressure is applied
to force it into the capacitor through the eyelet./

/Capacitor is then removed from the chamber and the wire lead is
soldered onto the eyelet./

I never figured that WATER SOAKING can be used as a part of the
manufacturing process for a PIO capacitor.

I also understand that this water, once that the external envelope was
cast, was evacuated thru the use of vacuum.

This means that the water within the envelope was forced to _boil_ when
the pressure was lowered.

What was the time allowed for the water vapor to escape ?

What if some water (or some oxidation on the aluminum plates) remained
inside the capacitor before the “oil” was forced inside the envelope and
the “tip” sealed ??

Can it ultimately explain why they failed so bad ??

It remembers me the failure mechanism described in the article about the
BBoD failures on a SX-88 by this guy in Germany we read some time ago.

Not that those BBoDs will have stayed good forever without the use of
water during their manufacturing process: all the PIO we know are
failing sooner or later (except the ones in gas-tight enclosures) but
can it be that the Sprague BBoDs failed earlier because of this
manufacturing process ?

Related to the reference (and the doubts of Richard) about the
capacitors “sound”:

At an earlier age, I was bitten by two bugs: Radio was the first, but
Audio was the second, to the point that I earned my living for some time
with audio amplifier design (tube based variants).

From a lot of testing and listening sessions, I can testify that no
capacitor “sound” the same and certainly not like no capacitor at all
for most.

All the capacitor variants changes the sound reconstruction, like adding
a different color to the picture if I can compare the effect with a
visual equivalent.

Pleasant or not, good or bad, all those “colorations” are judged by the
ears of the listeners, but they can definitively be heard.

There is no simple explanations for these effects, and sometime they
defies electronic laws, like some people that states that they prefer
the “sound” of a leaking PIO.

*73, Jacques, VE2JFE in Montreal*

_._,_._,_

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

Re: Sprague capacitors variants

#30071

开云体育

Hi all,

?

Following the address provided by Richard, I read, then downloaded the article and edited it before conversion in a .pdf.

See attached.

What scares me the most in it is the description of the manufacturing process for the “Bumblebees”:

Construction Details (eyelet variation):

Eyelet was soldered to a wound foil and left sticking out of the Bakelite phenolic case during the molding process.

Paper and foil slug is soaked with water before casing in the Bakelite to give the slug extra body and prevent the high pressure of the casting process from distorting the capacitor.

After the slug is encased in Bakelite, it is placed in a vacuum oven where moisture is allowed to escape through the eyelet.

Oil is then introduced into the vacuum chamber and pressure is applied to force it into the capacitor through the eyelet.

Capacitor is then removed from the chamber and the wire lead is soldered onto the eyelet.

?

I never figured that WATER SOAKING can be used as a part of the manufacturing process for a PIO capacitor.

I also understand that this water, once that the external envelope was cast, was evacuated thru the use of vacuum.

This means that the water within the envelope was forced to boil when the pressure was lowered.

What was the time allowed for the water vapor to escape ?

What if some water (or some oxidation on the aluminum plates) remained inside the capacitor before the “oil” was forced inside the envelope and the “tip” sealed ??

Can it ultimately explain why they failed so bad ??

It remembers me the failure mechanism described in the article about the BBoD failures on a SX-88 by this guy in Germany we read some time ago.

Not that those BBoDs will have stayed good forever without the use of water during their manufacturing process: all the PIO we know are failing sooner or later (except the ones in gas-tight enclosures) but can it be that the Sprague BBoDs failed earlier because of this manufacturing process ?

?

Related to the reference (and the doubts of Richard) about the capacitors “sound”:

At an earlier age, I was bitten by two bugs: Radio was the first, but Audio was the second, to the point that I earned my living for some time with audio amplifier design (tube based variants).

From a lot of testing and listening sessions, I can testify that no capacitor “sound” the same and certainly not like no capacitor at all for most.

All the capacitor variants changes the sound reconstruction, like adding a different color to the picture if I can compare the effect with a visual equivalent.

Pleasant or not, good or bad, all those “colorations” are judged by the ears of the listeners, but they can definitively be heard.

There is no simple explanations for these effects, and sometime they defies electronic laws, like some people that states that they prefer the “sound” of a leaking PIO.

?

73, Jacques, VE2JFE in Montreal

Sprague_PIO_Caps.pdf

Re: Sprague capacitors variants

#30070
Edited

Well done!

Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy

On Tuesday, April 30, 2024 at 05:09:47 PM CDT, don Root <drootofallevil@...> wrote:

Jim, ?the trade mark was filed about the time of the first ad, so the words spread quickly

?

--
don??? va3drl

Re: SX100 Sensitivity Pot replacement

#30069

Suggest you try Digitkey part number RV4N103C-ND which is made by Precision Electronics Corp manufacturer number RV4NAYSD103A. This is for a carbon resistance element. If you want a wire wound pot suggest you search for an old Clarostat RA20SASD103A on Ebay. I find several there.

Re: SX100 Sensitivity Pot replacement

#30068

I sent them an email. Hopefully they have one.
I really dont want to pull one out of another SX chassis thats here.
But if it comes down to it, thats what I will do

Re: SX100 Sensitivity Pot replacement

#30067

Keith,

? ? You might want to check with this fellow.

? ? ? ? ? ? ? ? ? Joe Connor

On Tuesday, April 30, 2024 at 08:08:56 PM EDT, Keith <kd4avp@...> wrote:

Discovered an issue with the pot for the sensitivity. Having intermittent connection and losing audio. That pot was a real pain to get out but managed to work it out.
Its a 10k linear, but looking around online, not seeing something similar. Tons of stuff for a guitar amp. But those dont quite fit the bill size wize.?
Suggestions?
I have taken the pot apart and will try to clean it and lube it but not sure it will be successful.?
Was buttoning up the radio after putting on the faceplate thats when the problem surfaced.
Wife said should have left it off and let it play.....I didnt say anything...she just doesnt understand. lol

SX100 Sensitivity Pot replacement

#30066

Discovered an issue with the pot for the sensitivity. Having intermittent connection and losing audio. That pot was a real pain to get out but managed to work it out.
Its a 10k linear, but looking around online, not seeing something similar. Tons of stuff for a guitar amp. But those dont quite fit the bill size wize.?
Suggestions?
I have taken the pot apart and will try to clean it and lube it but not sure it will be successful.?
Was buttoning up the radio after putting on the faceplate thats when the problem surfaced.
Wife said should have left it off and let it play.....I didnt say anything...she just doesnt understand. lol

Re: Sprague capacitors variants

#30065

Thank you for looking this up.
Note that a fairly popular movie was made of the novel "Black
Beauty" (1877) in 1946. Boy gets girl, girl gets boy, girl gets horse. I
probably saw it as a kid but don't remember it. The name "Black Beauty"
was probably still popular. I think this was also the name of the Green
Hornet's car (as the gleaming Black Beauty speeds into the night).

Show quoted text

On 4/30/2024 3:09 PM, don Root wrote:

Jim, ?the trade mark was filed about the time of the first ad, so the
words spread quickly

**

--
don??? va3drl

--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998

Re: Sprague capacitors variants

#30064
Edited

开云体育

Jim, ?the trade mark was filed about the time of the first ad, so the words spread quickly

?

--
don??? va3drl