Re: SX100 Sensitivity Pot replacement
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
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
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).
toggle quoted message
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
Jim, ?the trade mark was filed about the time of the first ad, so the words spread quickly
? -- don??? va3drl
|
Re: Sprague capacitors variants
Richard and Jim Because there are significant construction changes as time passed, there are at least 3 types of ¡°black beauty¡± ?ads from 1950 to about 1968 And if you want to relate to failures, it is best to segregate the types And it seems that they all look much the same in the ads But there are variations as there are pre-molded versions of the 109p or5160p
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Tuesday, April 30, 2024 3:05 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] 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.
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 -- don??? va3drl
|
Re: Sprague capacitors variants
Don Since the Sprague molded tubular caps are black and Sprague was making tons of them once they caught on and were used in everything, it is no surprise that they would be called Black Beauty by the sales staff.??
We all know the story behind the first National HRO receiver, don't we? Regards, Jim Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy
On Tuesday, April 30, 2024 at 04:21:05 PM CDT, don Root <drootofallevil@...> wrote:
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 ? ?
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
|
Re: Sprague capacitors variants
Richard, I saw that long ago , but that needs even more debunking ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Tuesday, April 30, 2024 3:41 AM
To: [email protected]
Subject: Re: [HallicraftersRadios] Sprague capacitors variants? 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
-- don??? va3drl
|
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 ? ?
toggle quoted message
Show quoted text
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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Show quoted text
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.
toggle quoted message
Show quoted text
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.
toggle quoted message
Show quoted text
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:
<>
toggle quoted message
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
|
don Root
Jim Whartenby
Floyd - K8AC