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Ok gentlemen.....Need help here before I make a mistake. Couple of the bees have me confused on values.?
Can I get a second opinion please?
Thanks
Keith
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?The first three color bands determine the value. Start with the color band nearest an end. The color coding is the same as the traditional three color resistor code.
In your first example below it’s red, red, orange or 22 times an orange multiplier of 1000 for 22,000 pF or .0022 uF. .002 is a commonly found film cap today.
Sprague Bumblebee color code values are always in pf. To convert to uF, divide by 1,000,000.?
In your second photo we see red, red, yellow. That’s 22 x 10000 = 220,000 pF/1,000,000 or .22 uF.
Summarizing, use the typical three color resistor code. First two colors are a value, the third is the multiplier, the result is always in pF and divide by 1,000,000 to get uF.
It’s pretty common to have difficulty discerning some colors after ~50-70 years, especially violet, gray, brown, etc. If in doubt, locate the cap on the schematic and see what the value is declared to be. You can almost always figure it out or confirm an uncertain color and value.
Dan WB4GRA
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On Mar 22, 2024, at 7:31?PM, Keith <kd4avp@...> wrote:
?Ok gentlemen.....Need help here before I make a mistake. Couple of the bees have me confused on values.? Can I get a second opinion please? Thanks Keith
<Bee1.jpg> <Bee2.jpg> <Bee3.jpg> <Bee4.jpg>
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Thank you Dan. I was on the right track. You are correct on having problems with the colors. I have found a good chart for reference now also is helping. Thankfully there are not a lot of these in this radio. ? ? ?
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From: [email protected] <[email protected]> On Behalf Of Dan
Sent: Friday, March 22, 2024 8:06 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] SX-100 Repair Problems - Bumblebees!? ?The first three color bands determine the value. Start with the color band nearest an end. The color coding is the same as the traditional three color resistor code. In your first example below it’s red, red, orange or 22 times an orange multiplier of 1000 for 22,000 pF or .0022 uF. .002 is a commonly found film cap today. Sprague Bumblebee color code values are always in pf. To convert to uF, divide by 1,000,000.? In your second photo we see red, red, yellow. That’s 22 x 10000 = 220,000 pF/1,000,000 or .22 uF. Summarizing, use the typical three color resistor code. First two colors are a value, the third is the multiplier, the result is always in pF and divide by 1,000,000 to get uF. It’s pretty common to have difficulty discerning some colors after ~50-70 years, especially violet, gray, brown, etc. If in doubt, locate the cap on the schematic and see what the value is declared to be. You can almost always figure it out or confirm an uncertain color and value. ?
On Mar 22, 2024, at 7:31?PM, Keith <kd4avp@...> wrote:
?Ok gentlemen.....Need help here before I make a mistake. Couple of the bees have me confused on values.?
Can I get a second opinion please?
Thanks
Keith
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Keith, the problem with old “bumble bees” is that he color bands color also change with time. ? Best I can see is : ? Bee1: the left one seems to be red, violet, yellow, white, blue = 2, 7, 0000, 9, 6 = 270000 pF = 0,27?F, 10%, 600V Bee1: right one: red, red, yellow, white, blue = 2, 2, 0000, 9, 6 = 220000 pF = 0,22?F, 10%, 600V Bee2: red, red, yellow, gray, red = 2, 2, 0000, 8, 2 = 220000 pF = 0,22?F, 10%, 200V Bee3: brown, gray, red, gray, blue = 1, 8, 00, 8, 6, = 1800pF = 0,0018?F, 10%, 600V Bee4: brown, gray, red, gray, blue = 1, 8, 00, 8, 6 = 1800?F = 0,0018?F, 10%, 600V ? On some bumble bees, the use of 8 or 9 on the tolerance band really means 10% practically. These ones can be measured on an impedance bridge at 1kHz, but… The values they measure now does not necessary reflects the original manufactured values. The dielectric (oil impregnated paper) do not have the same dielectric constant since it had been contaminated with ambient oxygen. ? Values out of the “standard” 10% decade values makes no sense, so… ? 73, Jacques, VE2JFE in Montreal
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Dang… I made an error on this one: Bee4: brown, gray, red, gray, blue = 1, 8, 00, 8, 6 = 1800?F = 0,0018?F, 10%, 600V I really meant : gray, red, gray, blue = 1, 8, 00, 8, 6 = 1800pF = 0,0018?F, 10%, 600V ? ? 73, Jacques, VE2JFE in Montreal
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??Keith, I happen to have an SX-100 Mk1A opened up on my bench right now. It works pretty good. Belongs to a friend and we went through it about a year ago replacing all the paper caps, PS cap, a few resistors, and did an alignment. Actually, we did several alignments since we became quite familiar with the process, enjoyed it, and it seemed to get a “little tweak” better each time.
We have it opened up again, mostly out of curiosity, as my friend and I want to check another thing or two we learned when recently going through a closely similar ham band only SX-111.
Point is, for comparative purposes if you need a photo of something, a voltage measured, etc., let me know and I’ll be happy to follow through.
Dan WB4GRA
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On Mar 22, 2024, at 8:29?PM, Keith <kd4avp@...> wrote:
? Thank you Dan. I was on the right track. You are correct on having problems with the colors. I have found a good chart for reference now also is helping. Thankfully there are not a lot of these in this radio. ? ? ? ? ?The first three color bands determine the value. Start with the color band nearest an end. The color coding is the same as the traditional three color resistor code. In your first example below it’s red, red, orange or 22 times an orange multiplier of 1000 for 22,000 pF or .0022 uF. .002 is a commonly found film cap today. Sprague Bumblebee color code values are always in pf. To convert to uF, divide by 1,000,000.? In your second photo we see red, red, yellow. That’s 22 x 10000 = 220,000 pF/1,000,000 or .22 uF. Summarizing, use the typical three color resistor code. First two colors are a value, the third is the multiplier, the result is always in pF and divide by 1,000,000 to get uF. It’s pretty common to have difficulty discerning some colors after ~50-70 years, especially violet, gray, brown, etc. If in doubt, locate the cap on the schematic and see what the value is declared to be. You can almost always figure it out or confirm an uncertain color and value. ?
On Mar 22, 2024, at 7:31?PM, Keith <kd4avp@...> wrote:
?Ok gentlemen.....Need help here before I make a mistake. Couple of the bees have me confused on values.?
Can I get a second opinion please?
Thanks
Keith
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Many thanks Jacques!
The replies received so far back up my initial values pretty well.
I was very unsure of Bees 3 & 4.?
Need to check and see if I have a value close to the .0018's.
Thinking there are some .0022's in my parts drawer.?
With the bag of assortments that came this week, I am sure to find something suitable.?
The filter caps arrive today. so that will come first!
73
Keith
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Thank you so much Dan. I may have to take you up on that. I have a really good schematic and slowly learning where everything in the radio is located in relation to the drawing.?
I am not an electronics major by any stretch. My career has been in the furniture industry for many years as an industrial engineer. Always had an interest in radio since a kid.
This is a fun thing for me. Learning a lot as I do these things as well.?
I am grateful there are groups like this with very knowledgeable people to share what they have learned and experienced.
73
Keith
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22000/1000000 is not .0022.? According to my Chinese calculator.
Bill
On Saturday, March 23, 2024 at 08:14:11 AM EDT, Keith <kd4avp@...> wrote:
Thank you so much Dan. I may have to take you up on that. I have a really good schematic and slowly learning where everything in the radio is located in relation to the drawing.?
I am not an electronics major by any stretch. My career has been in the furniture industry for many years as an industrial engineer. Always had an interest in radio since a kid.
This is a fun thing for me. Learning a lot as I do these things as well.?
I am grateful there are groups like this with very knowledgeable people to share what they have learned and experienced.
73
Keith
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Really glad I waited on power application to this radio. Everyone of these tiny chiefs were in some form of break down or
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Progress….albeit slow. All the major caps replaced that I can easily do without taking the face off. Filter caps hit the mailbox anytime now. Will get those installed tmw. Fingers crossed.
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Its obvious that the Sprague Black Beauty caps (Bumble Bee) are not
the only ones to suffer from the casings disintegrating. These were
supposed to be much better than the cardboard and wax casings but had a
lot of problems.
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On 3/23/2024 10:32 AM, Keith wrote: Really glad I waited on power application to this radio. Everyone of
these tiny chiefs were in some form of break down or
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
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My struggle was reading the color bands reliably. Thankfully others chimed in who were much more familiar with the radio and the values.?
Amazing how much room you gain inside as those chassis as the large caps come out.
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Seems to me the older cap values are the same as for resistors and by standards for 10%... ”The series looks as follows: 1– 1.2 – 1.5 – 1.8 – 2.2 – 2.7 – 3.3 – 3.9 – 4.7 – 5.6 – 6.8 – 8.2 – ?10” From ???????? ? so ?if you can’t see the first color band? but the second ?is: ? black,??? it must be 10 ???? orange, it must be 3.3 ??? green,?? it must be 1.5 blue,? ?? it must be 5.6 white,?? it must be 3.9 gray, ??? it must be 1.8 or 6.8? ?? violet,?? it must be 2.7 ?or ?4.7 ?? red,?????? it must be 1.2 or 2.2 or ?8.2 ? brown, ?oops ?can’t be yellow, ?oops can’t be caveat; THIS INFO HAS NOT BEEN VERIFIED BY ANY RELIABLE ?SOURCE ? ? -- don??? va3drl
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Well Richard , they likely were much better … until they cracked open… do we know ? So when and why did many/most eventually crack open ?? did pressure from chemical decomposition build up and split them open? or did the case dry-out and shrink? Or did ?storage temp swings and humidity do it? , etc? Possibly ageing tests were only for 10 years ?? was there a standard by RMA or ? that? addressed life [expectancy]? Are there radios that survived without cracking ?cap casings because they entered a good care-home at an early age? Not done with babbling thoughts, but fingers were not rated for so many years either, so I give up. ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Richard Knoppow
Sent: Saturday, March 23, 2024 3:40 PM
To: [email protected]
Subject: Re: [HallicraftersRadios] SX-100 Repair Problems - Bumblebees!? Its obvious that the Sprague Black Beauty caps (Bumble Bee) are not
the only ones to suffer from the casings disintegrating. These were
supposed to be much better than the cardboard and wax casings but had a
lot of problems.
On 3/23/2024 10:32 AM, Keith wrote: Really glad I waited on power application to this radio. Everyone of
these tiny chiefs were in some form of break down or
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
-- don??? va3drl
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You might find the following blog and its follow up on replacement of the bumble bee caps on the selectivity switch of a SX-96 informative: . Note SX-100 has identical switch and caps.
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Don't know. The cases are probably Bakelite but most Bakelite
objects do not disintegrate. Something was done wrong in the composition
or molding of the cases which caused them to crack and split after a
time. the Sprague caps seem to have done this in a short time. Short
enough to cause Hammarlund and the Army to require changing all paper
caps in the SP-600 to disc ceramics. You would have to find the
modification work orders to find the dates. Hammarlund changed the type
of caps well within the production dates of the SP-600 and probably
other models. I was warned about Black Beauties and also about Micamold
caps by my mentor in highschool. Evidently their bad behavior was well
known in the engineering community.
Black Beauty caps of 600 Volt rating were oil filled, the oil being
introduced via a tubular lead on one end. This lead was sealed by
soldering a wire in it. If too much heat was applied when installing the
cap the seal was broken and the oil leaked out. These caps are
sometimes found with a coating of oil on them.
Not all cracked, for instance, a great many Sprague caps were used
by Hewlett-Packard. These do not seem to have suffered the early
failures of the Hammarlund caps. All go bad after a time but that is
typical of paper caps of all makes.
The Sprague caps I have dissected all had distorted windings. I have
not seem this in other paper caps. All I can think is that something
happened in the molding process. While all the flat Micamold caps I've
come across were bad none showed any mechanical problems. Same with
similar Solar flat paper caps.
FWIW, Sprague Black Beauty caps were sold as deluxe caps especially
designed for high voltage and high temperature television use.
I don't know who made the white molded caps with stripes shown in
some illustrations of the SP-600 or whether they suffered from the same
problems.
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On 3/23/2024 2:53 PM, don Root wrote: Well Richard , they likely were much better … until they cracked open…
do we know ?
So when and why did many/most eventually crack open ?? did pressure from
chemical decomposition build up and split them open? or did the case
dry-out and shrink? Or did ?storage temp swings and humidity do it? , etc?
Possibly ageing tests were only for 10 years ?? was there a standard by
RMA or ? that? addressed life [expectancy]?
Are there radios that survived without cracking ?cap casings because
they entered a good care-home at an early age?
Not done with babbling thoughts, but fingers were not rated for so many
years either, so I give up.
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
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Thanks for sharing this! It really did help. I am hoping it will be more accessible when the faceplate comes off, but not sure. May have pull it out to replace them. But that will be last thing. Want to make sure it even plays before going that far.
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Richard, ? When you wrote: I don't know who made the white molded caps with stripes shown in
some illustrations of the SP-600 or whether they suffered from the same
problems.
Did you really mean pale gray, like the ones in the attached picture ? If so, the answer is Cornell-Dubilier. And yes, they were victims of the same disease as the Bumble-Bees. ? 73, Jacques, VE2JFE in Montreal
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Those are the ones, thank you for identifying them. C-D had a good
reputation but so did Sprague. Evidently something went wrong. The one
at the top has what looks like a mold seam but could be a crack.
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On 3/23/2024 7:38 PM, Jacques_VE2JFE wrote: Richard,
When you wrote:
I don't know who made the white molded caps with stripes shown in
some illustrations of the SP-600 or whether they suffered from the same
problems.
Did you really mean pale gray, like the ones in the attached picture ?
If so, the answer is Cornell-Dubilier.
And yes, they were victims of the same disease as the Bumble-Bees.
*73, Jacques, VE2JFE in Montreal*
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
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Jacques_VE2JFE
don Root