Re: Sprague capacitors variants
Hi Jim I did not call early ?molded phenolic resin tubulars ?by the names ¡°black beauty¡± or even ¡°telecaps¡± as they did not use that term early on, but it seems that they became telecaps and then ¡°black beauty¡± telecaps ??as in in the ad I posted before =?? ?????????? ???? ?if you look at other forums not all BBs were striped. I have looked at many many ads, and am left asking what is the deal about stripes? And it ?seems to me early ads were salesman¡¯s hype. ? Re The text in the first ad you found says that the TM (Tubular Molded?) says that it has been in development for 4 years.? That puts it at the end of WW2.? Printed values and logo, no stripes, so I'm not sure that the TM was ready for prime time.? Same as seen in your second ad. ? The earliest ad that I found for the first generation Black Beauties is September, 1948 in "Electronics," paper page 58, pdf page 62.? Still not called Black Beauty but the value is shown in color coded color stripes.
? the earliest TM I have stored away is ??????? first? ???"TM" units. ?See pdf? 21 --- ? ? re? ??A more detailed ad is in "Electronics," July, 1950, paper page 119.? Still not called Black Beauty, it is referred to as a molded tubular, with color stripes, as it is in the above ad. I¡¯ll take your word , but look at this,:a month earlier ?????????? 1950-06 ?BlackBeautyTelecap? ?? pdf???? 4? -----??? ? ? ? Re? Found an ad in "Electronics,"?January, 1956 on paper page 11,?calling the molded tubular capacitor a Black Beauty,? ?They switched to type 109p that used HCX [not oil] ?in nov 1955 ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Jim Whartenby via groups.io
Sent: Tuesday, April 30, 2024 2:52 AM
To: [email protected]
Subject: Re: [HallicraftersRadios] Sprague capacitors variants? The text in the first ad you found says that the TM (Tubular Molded?) says that it has been in development for 4 years.? That puts it at the end of WW2.? Printed values and logo, no stripes, so I'm not sure that the TM was ready for prime time.? Same as seen in your second ad. The earliest ad that I found for the first generation Black Beauties is September, 1948 in "Electronics," paper page 58, pdf page 62.? Still not called Black Beauty but the value is shown in color coded color stripes. A more detailed ad is in "Electronics," July, 1950, paper page 119.? Still not called Black Beauty, it is referred to as a molded tubular, with color stripes, as it is in the above ad. Found an ad in "Electronics,"?January, 1956 on paper page 11,?calling the molded tubular capacitor a Black Beauty,? I will search the jobber magazines for the Black Beauty trade name but I suspect that the equipment designers got their ideas from the more technical pubs like "Electronics."? If anyone finds a Black Beauty ad before 1955, give a holler. Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy On Monday, April 29, 2024 at 04:45:19 PM CDT, don Root <drootofallevil@...> wrote: Richard, also Jacques and all re¡..The early one does not list any molded paper caps Here is the first ad I found for the molded caps , no telecap or black beauty yet ??? ? ^^ 1948-02? Radio-Maintenance- pdf? 21 ---
? ¡and the first telecap ad ? ? ^^? 1949-04 RSD- Pdf?? 12 ? ?
? ? And telecaps are referred to by the expression ?[These "Black Beauties"] ?? ^^ 1950-04 Radio-News- pdf?? 16??? -----?? ? then two month later? =? Sprague Black Beauty Telecap? Tubulars ?? ?????????? ???? ^^?? 1950-06 Radio-Maintenance- pdf???? 4? -----? ? ?
? RE ?In any case, I believe these are the replacements for the Black Beauty caps I don¡¯t understand this. ???Black Beauty began in 1950, and ran in ads to 1967. but the construction changed first brought in HCX and later Difilm ? ? ? FWIW, I have a couple of hard copy "Radio's Master" catalogues.
Others are on the worldradiohistory.org site. The ones I have are 1947
and 1953. The early one does not list any molded paper caps, the 1953
edition shows Sprague Telecap, called Black Beauty in quotes but without
RMA code striping. These are described as "dry process" caps with the
same qualities as oil filled ones. In any case, I believe these are the
replacements for the Black Beauty caps. I am too lazy to look at the
on-line catalogues but, from memory, it seems to me that BB was used as
a trademark about 1950.
The 1953 catalog also shows Sprague Vitamin-Q caps.
Some older Hewlett-Packard instruments, like early 400D and similar,
have molded sprague caps with RMA coding on them. These do not seem to
have failed and don't show the mechanical disintegration of the caps in
the Hammarlund receivers. I don't know if they are the same caps or not.
The signal corps issued modification work orders to replace all
paper caps in the SP-600 about the mid 1950's, I don't know the exact
date. The caps were replaced with disc ceramic types.
The Black Beauty caps were advertised as "deluxe quality at no
higher price" for use in locations with high heat. Telecaps were
advertised for similar applications especially, as the name implies, in
television sets. Other manufacturers made similar molded caps, for
instance, Cornell-Dublier made Blue Cubs. Paper caps of all types have
limited lives but the Black Beauty seems to have had a special problem.
On 3/25/2024 1:17 PM, Richard Knoppow wrote: Sprague began using the trade name "Telecap" after the Black Beauty
was discontinued. I don't know for certain but think they were the same
capacitor with whatever was wrong fixed. These look like their
advertising illustrations, no stripes, values marked in numerals. Again,
I don't know the exact dates but think the BB problems happened about
the mid or late 1950s.
On 3/25/2024 11:43 AM, Jacques_VE2JFE wrote:
Hi all, I still had, until recently, few ¡°Bumblebee-coded¡± 0.01?F, 600V
Sprague capacitors that passed all the leakage tests with flying colors.
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998 -- don??? va3drl
|
Re: HT-44 idle current drift
Floyd - K8AC <floydsense@...> wrote Didn't notice this previously when testing, but, when the tube bias is set per the manual, the idling current continuously drifts upwards. For example, I can set the bias at .9 V (read across the 10 ohm resistor) and it will drift up to 1 V over the next minute or two. After repeatedly adjusting the bias, it's no longer possible to achieve the 1 volt reading with the bias pot turned full clockwise. Seems to be that the new tubes I purchased are likely soft? The plate voltage at the test pins on the power supply is 682 VDC. <snip> Hi, Are the two 6DQ5s balanced? You can check by removing one (NOT just removing a plate cap connector), and retesting the resting current. Each tube should draw an indicated 0.45V on the 10 Ohm resistor, when set to the bias voltage you started at. Also, 0.9V indicates 90mA for the pair. At 680V plate volts, that means 61 Watts plate dissipation. The 6DQ5s are only rated at 48W max plate dissipation for the pair, so the pair are already being overloaded at that resting current, even if perfectly balanced. If the tubes are unbalanced, one may be hogging most of the plate current, pushing it way over its maximum rated plate dissipation. The plate current drifts as one tube is possibly slowly dying. 73, Ed Knobloch K4PF
|
Re: HT-44 idle current drift
Sounds like they are a bit gassy.
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On 4/30/2024 12:14 PM, Floyd - K8AC wrote: I installed a different set of tubes and after the warm up period
recommended, the idle current is stable and I can set the idle current
to 1 VDC well within the range of the bias pot.? Guess the other tubes
have a problem.
73, Floyd - K8AC
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: Sprague capacitors variants
That's perfectly fine. I think a combination is possible. Actually,
I think its necessary. Probably my strongest motivation is curiosity.
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On 4/30/2024 12:11 PM, Jim Whartenby via groups.io wrote: Richard
I completely agree with you, I had just put on my history cap after
removing the engineering one!
Regards,
Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.
Murphy
On Tuesday, April 30, 2024 at 02:05:16 PM CDT, Richard Knoppow
<1oldlens1@...> wrote:
Well, I think the construction is important because the same trade
name was evidently used for multiple similar products. The web site is
not of good academic quality since it lacks dates and findable
citations. However, it does give some idea of the time line. I am
generally skeptical of statements made on hi-fi or electronic musical
instrument sites. The name "Bumble Bee" was never used by Sprague, of
anyone else, for a commercial product but seems to refer to the use of
RMA color coding stripes, something done on many capacitors.
I think that you, as am I, am interested in the particular caps that
failed so miserably in the Hammarlund receivers.
The web site I linked seems to suggest the author has a lot more
history than he is giving us. Maybe worth a search into the old trade
journals, which is, I suspect, where he got his information.
On 4/30/2024 10:01 AM, Jim Whartenby via groups.io wrote:
Richard
I've found this site awhile ago.? No dates are shown for the ads or for
the data sheets.
My interest is in the time line, not the construction of the capacitor.
I've not seen Sprague capacitors earlier then the striped variation in
any radio that I have reworked.? ?I feel that Sprague was testing the
waters with the early ads as they developed the Black Beauty.? This is
just my opinion so I searched through the World Radio History site for
data to confirm this but I didn't find much.
Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.
Murphy
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: HT-44 idle current drift
I installed a different set of tubes and after the warm up period recommended, the idle current is stable and I can set the idle current to 1 VDC well within the range of the bias pot.? Guess the other tubes have a problem.
73, Floyd - K8AC
|
Re: Sprague capacitors variants
Richard I completely agree with you, I had just put on my history cap after removing the engineering one! Regards, Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
On Tuesday, April 30, 2024 at 02:05:16 PM CDT, Richard Knoppow <1oldlens1@...> wrote:
Well, I think the construction is important because the same trade
name was evidently used for multiple similar products. The web site is
not of good academic quality since it lacks dates and findable
citations. However, it does give some idea of the time line. I am
generally skeptical of statements made on hi-fi or electronic musical
instrument sites. The name "Bumble Bee" was never used by Sprague, of
anyone else, for a commercial product but seems to refer to the use of
RMA color coding stripes, something done on many capacitors.
I think that you, as am I, am interested in the particular caps that
failed so miserably in the Hammarlund receivers.
The web site I linked seems to suggest the author has a lot more
history than he is giving us. Maybe worth a search into the old trade
journals, which is, I suspect, where he got his information.
On 4/30/2024 10:01 AM, Jim Whartenby via groups.io wrote: Richard
I've found this site awhile ago.? No dates are shown for the ads or for
the data sheets.
My interest is in the time line, not the construction of the capacitor.
I've not seen Sprague capacitors earlier then the striped variation in
any radio that I have reworked.? ?I feel that Sprague was testing the
waters with the early ads as they developed the Black Beauty.? This is
just my opinion so I searched through the World Radio History site for
data to confirm this but I didn't find much.
Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.
Murphy
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: Sprague capacitors variants
Well, I think the construction is important because the same trade
name was evidently used for multiple similar products. The web site is
not of good academic quality since it lacks dates and findable
citations. However, it does give some idea of the time line. I am
generally skeptical of statements made on hi-fi or electronic musical
instrument sites. The name "Bumble Bee" was never used by Sprague, of
anyone else, for a commercial product but seems to refer to the use of
RMA color coding stripes, something done on many capacitors.
I think that you, as am I, am interested in the particular caps that
failed so miserably in the Hammarlund receivers.
The web site I linked seems to suggest the author has a lot more
history than he is giving us. Maybe worth a search into the old trade
journals, which is, I suspect, where he got his information.
toggle quoted message
Show quoted text
On 4/30/2024 10:01 AM, Jim Whartenby via groups.io wrote: Richard
I've found this site awhile ago.? No dates are shown for the ads or for
the data sheets.
My interest is in the time line, not the construction of the capacitor.
I've not seen Sprague capacitors earlier then the striped variation in
any radio that I have reworked.? ?I feel that Sprague was testing the
waters with the early ads as they developed the Black Beauty.? This is
just my opinion so I searched through the World Radio History site for
data to confirm this but I didn't find much.
Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.
Murphy
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Didn't notice this previously when testing, but, when the tube bias is set per the manual, the idling current continuously drifts upwards.? For example, I can set the bias at .9 V (read across the 10 ohm resistor) and it will drift up to 1 V over the next minute or two.? After repeatedly adjusting the bias, it's no longer possible to achieve the 1 volt reading with the bias pot turned full clockwise.? Seems to be that the new tubes I purchased are likely soft?? The plate voltage at the test pins on the power supply is 682 VDC.? The range of adjustment of the bias pot as measured at the wiper is -111 VDC to -154 VDC.? What do you say?
73, Floyd - K8AC
|
Re: Sprague capacitors variants
Richard I've found this site awhile ago.? No dates are shown for the ads or for the data sheets.??
My interest is in the time line, not the construction of the capacitor.? I've not seen Sprague capacitors earlier then the striped variation in any radio that I have reworked.? ?I feel that Sprague was testing the waters with the early ads as they developed the Black Beauty.? This is just my opinion so I searched through the World Radio History site for data to confirm this but I didn't find much. Jim
Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
On Tuesday, April 30, 2024 at 02:41:23 AM CDT, Richard Knoppow <1oldlens1@...> wrote:
A brief search found this:
<>
On 4/29/2024 11:52 PM, Jim Whartenby via groups.io wrote: Don
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: Sprague capacitors variants
After reading this article again I find I disagree with some things
in it, for one thing he states that you can't figure out how caps were
made by dissecting them, I think that is wrong. While you probably can't
figure out a complex manufacturing method you can certainly see what the
materials are. Since this page seems aimed at guitar players it talks
about the "sound" of capacitors, something I am very skeptical about. I
do think leaky coupling caps may sound different because they affect the
bias of following stages and its possible that dielectric absorption may
have some effect for the most part I don't think one can tell the
difference in caps by sound, perhaps excepting Hi-K ceramic caps which
have serious voltage coefficient of capacitance. Paper caps, BTW, have
very low dielectric absorption.
In any case, the article gives some idea of the different capacitors
made by Sprague under the same or similar names Note that the "difilm"
caps are dated 1960, long after the faulty Bumble Bee caps were made.
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On 4/30/2024 12:41 AM, Richard Knoppow wrote: A brief search found this:
< <>
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: Sprague capacitors variants
A brief search found this:
<>
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Show quoted text
On 4/29/2024 11:52 PM, Jim Whartenby via groups.io wrote: Don
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: Sprague capacitors variants
Don The text in the first ad you found says that the TM (Tubular Molded?) says that it has been in development for 4 years.? That puts it at the end of WW2.? Printed values and logo, no stripes, so I'm not sure that the TM was ready for prime time.? Same as seen in your second ad.
The earliest ad that I found for the first generation Black Beauties is September, 1948 in "Electronics," paper page 58, pdf page 62.? Still not called Black Beauty but the value is shown in color coded color stripes.
A more detailed ad is in "Electronics," July, 1950, paper page 119.? Still not called Black Beauty, it is referred to as a molded tubular, with color stripes, as it is in the above ad.
Found an ad in "Electronics,"?January, 1956 on paper page 11,?calling the molded tubular capacitor a Black Beauty,?
I will search the jobber magazines for the Black Beauty trade name but I suspect that the equipment designers got their ideas from the more technical pubs like "Electronics."? If anyone finds a Black Beauty ad before 1955, give a holler.
Regards, Jim Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
On Monday, April 29, 2024 at 04:45:19 PM CDT, don Root <drootofallevil@...> wrote:
Richard, also Jacques and all re¡..The early one does not list any molded paper caps Here is the first ad I found for the molded caps , no telecap or black beauty yet ??? ? ^^ 1948-02? Radio-Maintenance- pdf? 21 --- ? ¡and the first telecap ad ? ? ^^? 1949-04 RSD- Pdf?? 12 ? ? ? ? And telecaps are referred to by the expression ?[These "Black Beauties"] ?? ^^ 1950-04 Radio-News- pdf?? 16??? -----?? ? then two month later? =? Sprague Black Beauty Telecap? Tubulars ?? ?????????? ???? ^^?? 1950-06 Radio-Maintenance- pdf???? 4? -----? ? ? ? RE ?In any case, I believe these are the replacements for the Black Beauty caps I don¡¯t understand this. ???Black Beauty began in 1950, and ran in ads to 1967. but the construction changed first brought in HCX and later Difilm ? ?
From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Sunday, April 28, 2024 10:42 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Sprague capacitors variants ? FWIW, I have a couple of hard copy "Radio's Master" catalogues.
Others are on the worldradiohistory.org site. The ones I have are 1947
and 1953. The early one does not list any molded paper caps, the 1953
edition shows Sprague Telecap, called Black Beauty in quotes but without
RMA code striping. These are described as "dry process" caps with the
same qualities as oil filled ones. In any case, I believe these are the
replacements for the Black Beauty caps. I am too lazy to look at the
on-line catalogues but, from memory, it seems to me that BB was used as
a trademark about 1950.
The 1953 catalog also shows Sprague Vitamin-Q caps.
Some older Hewlett-Packard instruments, like early 400D and similar,
have molded sprague caps with RMA coding on them. These do not seem to
have failed and don't show the mechanical disintegration of the caps in
the Hammarlund receivers. I don't know if they are the same caps or not.
The signal corps issued modification work orders to replace all
paper caps in the SP-600 about the mid 1950's, I don't know the exact
date. The caps were replaced with disc ceramic types.
The Black Beauty caps were advertised as "deluxe quality at no
higher price" for use in locations with high heat. Telecaps were
advertised for similar applications especially, as the name implies, in
television sets. Other manufacturers made similar molded caps, for
instance, Cornell-Dublier made Blue Cubs. Paper caps of all types have
limited lives but the Black Beauty seems to have had a special problem.
On 3/25/2024 1:17 PM, Richard Knoppow wrote: Sprague began using the trade name "Telecap" after the Black Beauty
was discontinued. I don't know for certain but think they were the same
capacitor with whatever was wrong fixed. These look like their
advertising illustrations, no stripes, values marked in numerals. Again,
I don't know the exact dates but think the BB problems happened about
the mid or late 1950s.
On 3/25/2024 11:43 AM, Jacques_VE2JFE wrote:
Hi all, I still had, until recently, few ¡°Bumblebee-coded¡± 0.01?F, 600V
Sprague capacitors that passed all the leakage tests with flying colors.
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
--
don??? va3drl
|
Re: Sprague capacitors variants
In the clip of an ad in your last message. At the bottom where it
shows the solder seal and refers to large, metal encased, oil
capacitors. This appears to refer to large transmitting caps rather than
to the tubular Vitamin-Q ones although I think Vitamin-Q referred to the
filling and that there were square can caps made with that name.
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On 4/29/2024 6:49 PM, don Root wrote: You have many comments Richard
Re The metal cased caps the ad ?I did not see any ??¡°metal cased caps¡±
?in what I sent, but maybe my eyes are tired, where is it?
Vitamin-Q caps ?were in ads in 1943, and the ¡°elusive oil¡± just might be
±Ê°äµþ¡¯²õ????????????
That¡¯s it for now
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: Sprague capacitors variants
You have many comments Richard Re ?The metal cased caps the ad ?I did not see any ??¡°metal cased caps¡± ?in what I sent, but maybe my eyes are tired, where is it? ? Vitamin-Q caps ?were in ads in 1943, and the ¡°elusive oil¡± just might be ±Ê°äµþ¡¯²õ???????????? That¡¯s it for now ? ?? ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Monday, April 29, 2024 7:11 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Sprague capacitors variants? A couple of other thoughts: The metal cased caps the ad refers to are
probably the Vitamin-Q caps I mentioned. These are metal cases with
glass seals on the ends. I would guess from the description of the
Telecap that they were filled with oil after being molded. The lead on
one side of the cap is tubular and was used for filling, then a wire
lead was soldered into it to seal it and act as the lead on that side.
One mode of failure is that the heat of installing melts out the
sealing solder and allows the oil to leak out. I think the oil filling
was applied only to 600 volt caps, not to the lower voltage ones.
I have dissected a number of these caps. Often the cases are cracked
and sometimes have disintegrated. The cap windings are distorted. Its
possible that might have been done to adjust their values but I doubt
it, I think it is due to mechanical force applied by the casing as it
shrunk or, perhaps, from the oil filling process. In any case, the ads
for the later Telecap indicate they were NOT oil filled.
BB caps with RMA coding seem to have been quite widely used but
don't seem to have come apart in equipment other than the SP-600
suggesting that it was partly due to manufacturing technique at Hammarlund.
FWIW, the Mica-Mold paper caps did not fall apart nor have signs of
mechanical damage. I have no idea how long their lives were. The ones I
replaced in my RCA AR-88 were at least seventy years old. In the AR-88
the caps specified in the original handbook were RCA made mica caps.
Because mica was a strategic material during the war the paper caps were
substituted. Evidently, they performed well enough for RF use. The
original RCA caps, where found, are all good but the Mica-Mold caps must
all be replaced. I was warned about Mica-Mold by my engineering mentor
but that was when they were very old. Mica-Mold made a wide range of
caps, they disappeared around 1948 along with Solar, I have not been
able to find out what happened to either.
On 4/29/2024 2:45 PM, don Root wrote: Richard, also Jacques and all
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
-- don??? va3drl
|
Re: Sprague capacitors variants
A couple of other thoughts: The metal cased caps the ad refers to are
probably the Vitamin-Q caps I mentioned. These are metal cases with
glass seals on the ends. I would guess from the description of the
Telecap that they were filled with oil after being molded. The lead on
one side of the cap is tubular and was used for filling, then a wire
lead was soldered into it to seal it and act as the lead on that side.
One mode of failure is that the heat of installing melts out the
sealing solder and allows the oil to leak out. I think the oil filling
was applied only to 600 volt caps, not to the lower voltage ones.
I have dissected a number of these caps. Often the cases are cracked
and sometimes have disintegrated. The cap windings are distorted. Its
possible that might have been done to adjust their values but I doubt
it, I think it is due to mechanical force applied by the casing as it
shrunk or, perhaps, from the oil filling process. In any case, the ads
for the later Telecap indicate they were NOT oil filled.
BB caps with RMA coding seem to have been quite widely used but
don't seem to have come apart in equipment other than the SP-600
suggesting that it was partly due to manufacturing technique at Hammarlund.
FWIW, the Mica-Mold paper caps did not fall apart nor have signs of
mechanical damage. I have no idea how long their lives were. The ones I
replaced in my RCA AR-88 were at least seventy years old. In the AR-88
the caps specified in the original handbook were RCA made mica caps.
Because mica was a strategic material during the war the paper caps were
substituted. Evidently, they performed well enough for RF use. The
original RCA caps, where found, are all good but the Mica-Mold caps must
all be replaced. I was warned about Mica-Mold by my engineering mentor
but that was when they were very old. Mica-Mold made a wide range of
caps, they disappeared around 1948 along with Solar, I have not been
able to find out what happened to either.
toggle quoted message
Show quoted text
On 4/29/2024 2:45 PM, don Root wrote: Richard, also Jacques and all
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: Sprague capacitors variants
This is about when molded paper caps were introduced although one
can consider the Mica-Mold flat caps that look like mica to be molded
paper. Those evidently date from the early 1940s since they are found in
WW-2 vintage receivers.
I don't know when Sprague began to use the name Black Beauty for
its caps but must have been about 1950, that is about when the first
SP-600 receivers were built (although advertised earlier). Telecap seems
to have been a replacement trade-name for the former Black Beauty, I
suspect after the BB caps began to fail rapidly. Since the trade
journals made their living off of advertising I suspect there won't be
much about this in them.
Not all molded paper caps had problems, in fact, the BB seems to
have been unique. There were many brands. All paper caps eventually
degrade although some have very long lifetimes. For instance, oil filled
transmitting paper caps can last for decades, but the resin molded ones
and wax paper ones probably had lives of about ten years.
Sprague was a well established company with a reputation for good
quality so the failure of the BB caps must have been a blow to them.
Of course the name Bumble Bee was a nick name given to them long
after they were made, never used by Sprague, and inspired by the RMA
color stripes on them, which were also used on other brands for a time.
Its interesting that Sprague also made the Vitamin-Q paper caps
which have a very good reputation for reliability and long life.
toggle quoted message
Show quoted text
On 4/29/2024 2:45 PM, don Root wrote: Richard, also Jacques and all
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
|
Re: Sprague capacitors variants
Richard, also Jacques and all re¡..The early one does not list any molded paper caps Here is the first ad I found for the molded caps , no telecap or black beauty yet ??? ? ^^ 1948-02? Radio-Maintenance- pdf? 21 --- ? ¡and the first telecap ad ? ? ^^? 1949-04 RSD- Pdf?? 12 ? ? ? ? And telecaps are referred to by the expression ?[These "Black Beauties"] ?? ^^ 1950-04 Radio-News- pdf?? 16??? -----?? ? then two month later? =? Sprague Black Beauty Telecap? Tubulars ?? ?????????? ???? ^^?? 1950-06 Radio-Maintenance- pdf???? 4? -----? ? ? ? RE ?In any case, I believe these are the replacements for the Black Beauty caps I don¡¯t understand this. ???Black Beauty began in 1950, and ran in ads to 1967. but the construction changed first brought in HCX and later Difilm ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Sunday, April 28, 2024 10:42 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] Sprague capacitors variants? FWIW, I have a couple of hard copy "Radio's Master" catalogues.
Others are on the worldradiohistory.org site. The ones I have are 1947
and 1953. The early one does not list any molded paper caps, the 1953
edition shows Sprague Telecap, called Black Beauty in quotes but without
RMA code striping. These are described as "dry process" caps with the
same qualities as oil filled ones. In any case, I believe these are the
replacements for the Black Beauty caps. I am too lazy to look at the
on-line catalogues but, from memory, it seems to me that BB was used as
a trademark about 1950.
The 1953 catalog also shows Sprague Vitamin-Q caps.
Some older Hewlett-Packard instruments, like early 400D and similar,
have molded sprague caps with RMA coding on them. These do not seem to
have failed and don't show the mechanical disintegration of the caps in
the Hammarlund receivers. I don't know if they are the same caps or not.
The signal corps issued modification work orders to replace all
paper caps in the SP-600 about the mid 1950's, I don't know the exact
date. The caps were replaced with disc ceramic types.
The Black Beauty caps were advertised as "deluxe quality at no
higher price" for use in locations with high heat. Telecaps were
advertised for similar applications especially, as the name implies, in
television sets. Other manufacturers made similar molded caps, for
instance, Cornell-Dublier made Blue Cubs. Paper caps of all types have
limited lives but the Black Beauty seems to have had a special problem.
On 3/25/2024 1:17 PM, Richard Knoppow wrote: Sprague began using the trade name "Telecap" after the Black Beauty
was discontinued. I don't know for certain but think they were the same
capacitor with whatever was wrong fixed. These look like their
advertising illustrations, no stripes, values marked in numerals. Again,
I don't know the exact dates but think the BB problems happened about
the mid or late 1950s.
On 3/25/2024 11:43 AM, Jacques_VE2JFE wrote:
Hi all, I still had, until recently, few ¡°Bumblebee-coded¡± 0.01?F, 600V
Sprague capacitors that passed all the leakage tests with flying colors.
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998 -- don??? va3drl
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Re: WTB: 1N3487, NTE506, or equivalent for my PS-150-120
I replaced them with BY133s.? Rating 1.3 kV, 1.0A.? $1.64 for 10 pieces at DK.
Halden VE7UTS
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Re: 5T restoration - IF cans and R4 toasting
Thank-you.? I appreciate your response as I do all feedback I receive.? I've gained a terrific amount of knowledge on these radios from this group and all of its contributors.?
Those caps had been replaced.? The loud "hum" cutting in and out turned out to be one of the rusty trimmers on top of the 2nd IF transformer.? Just touching that one screw could cause the "hum" to come or go, ?I suppose actually a low pitched out of tune IF squeal/motor-boating.? Removal and a good cleaning of the trimmer resolved that issue.? The oddball ohm rating on the coils seems to make no difference to operation.? Replacing the 6AF made no difference to operation despite how the original tube tests. ?I replaced the power transformer with a Stancor P8306 I had on the shelf and although it's a low 40ma supply where I think a 70ma is needed, the radio is alive and working all three bands.? R4 I changed to a 2W resistor and it seems OK at that wattage.? The 1500ohm dummy load for the open field coil will stay.? Since it's going to be more of a mantle type piece rather than a daily player I may leave it that way.? Played the chassis for an hour yesterday and was pleased with it's resurrected performance.? The BFO works too.? I'll get the reworked chassis final assembled and that spring loaded belt drive tuning in working order this week.
Now for the cabinet....
--
Dan
K1DTS
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Re: WTB: 1N3487, NTE506, or equivalent for my PS-150-120
Thank you to all who replied. The diodes have been sourced and purchased.
73,
Jeff
W8KZW
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don Root
Floyd - K8AC
Jim Whartenby