Re: SX-100 Repair Problems - Bumblebees!
Best 73 Franz (HB9HPZ) ? ? 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 ? ? ?
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Re: SX-100 Repair Problems - Bumblebees!
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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Re: SX-100 Repair Problems - Bumblebees!
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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Re: SX-100 Repair Problems - Bumblebees!
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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Re: SX-100 Repair Problems - Bumblebees!
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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Re: SX-100 Repair Problems - Bumblebees!
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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Re: SX-100 Repair Problems - Bumblebees!
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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Re: SX-100 Repair Problems - Bumblebees!
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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Re: Thinking about an SX-117
The discovery of electromagnetism is indeed a fascinating subject.
In case you don't already have them, please find below some links that might be useful, and a .pdf of an article about Romagnosi's experiment. 73 Xavier (VE3XGS)
FROM
"Mr. Volta’s pile was prepared, built of round pieces of
zinc and copper, alternating with pieces of humid flannel with water
impregnated with ammoniac salt; a silver wire, divided in several pieces
like a chain, was attached to the pile. The last segment of the chain
passed through a glass tube, and from its exterior termination there
stretched a pure silver knob attached to the chain. After this was done,
he [the experimenter, Giandomenico Romagnosi] took an ordinary magnetic
needle, in the form of a nautical compass,boxed in a square wood plank;
and lifting up the crystal that enclosed it, he put it over a glass
insulator, near the aforementioned pile. Then, taking the silver chain
and holding it by the above-mentioned glass tube, he applied its end or
knob to the magnetic needle; and keeping the contact for a few seconds,
he made the needle deflect from the direction of the poles by a few
degrees. Taking off the silver chain,the needle remained steady in the
divergent direction that was given to it. He again applied the same
chain, and made the needle diverge even more from the polar direction,
and the needle always remained in the same place in which it was left,
in such a way that the polarity remained completely damped."
— Giandomenica Romagnosi, Description of His Experiments in Magnetism, May, 1802
..............................
FROM
"In 1802, an Italian lawyer called Gian Domenico Romagnosi published an account of an observation similar to Oersted’s. However, his article appeared in a newspaper and it wasn’t taken up by the scientific community. Romagnosi doesn’t appear to have followed up his preliminary findings." .............
Ohhh, I forgot the curiosity factor. There is always something to learn, or perhaps make you even more curious; a bit like kids opening Christmas presents. Right now I am still curious ?about how ??Gian Domenico Romagnosi [In 1802] ?fits into the picture of? the stuff we now call electricity and magnetism. Like some more recent radio questions, I’ll probably never know for sure… but ya gotta try. ? And Justin, if you know the “less than ideal” characteristics of a rig before you buy, then you won’t get too deflated when you try to use it. ? ? Don - You pretty much nailed my reasons!? To me it is very enjoyable to open up a box with a "dead" radio and after a few days work have come to life!
Floyd - Maybe I was a bit harsh but some of the shortcomings might irritate me!? It would probably be used for CW the majority of the time as I don't have an SSB transmitter.
73,
--
Justin B.
KI5GKD
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Re: Thinking about an SX-117
Ohhh, I forgot the curiosity factor. There is always something to learn, or perhaps make you even more curious; a bit like kids opening Christmas presents. Right now I am still curious ?about how ??Gian Domenico Romagnosi [In 1802] ?fits into the picture of? the stuff we now call electricity and magnetism. Like some more recent radio questions, I’ll probably never know for sure… but ya gotta try. ? And Justin, if you know the “less than ideal” characteristics of a rig before you buy, then you won’t get too deflated when you try to use it. ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Justin Bowser - KI5GKD
Sent: Saturday, March 23, 2024 1:47 AM
To: [email protected]
Subject: Re: [HallicraftersRadios] Thinking about an SX-117? Don - You pretty much nailed my reasons!? To me it is very enjoyable to open up a box with a "dead" radio and after a few days work have come to life!
Floyd - Maybe I was a bit harsh but some of the shortcomings might irritate me!? It would probably be used for CW the majority of the time as I don't have an SSB transmitter.
73,
--
Justin B.
KI5GKD -- don??? va3drl
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Re: Thinking about an SX-117
On Sat, Mar 23, 2024 at 01:47 AM, Justin Bowser - KI5GKD wrote:
Don - You pretty much nailed my reasons!? To me it is very enjoyable to open up a box with a "dead" radio and after a few days work have come to life!
Same here, Justin.? Back in the late 1970s, before prices of used stuff went crazy, I bought a Hallicrafters SX-88 sight unseen from a guy who described it as a "basket case".? Think I gave him $100 and paid for shipping.? Two boxes arrived - one had the cabinet - didn't look too bad.? The second large box contained a genuine plastic laundry basket containing all the parts and the chassis all wrapped up in newspaper.? Calling it a dead radio would not have done it justice.? After many, many hours spent in the basement workshop, it finally came to life and I was thrilled.? But I didn't think much of it as a CW receiver and so ended up passing it along to someone else.?? 73, Floyd
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Re: SX-100 Repair Problems - Bumblebees!
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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Well, interesting results today.? I received my "new" Johnson TR switch yesterday and had to recap its power supply and do a lot of physical cleanup work to it.? I next removed the antenna relay from the HT-44, restoring it to the unmodified state.? So now with the TR switch installed, the HT-44 antenna is connected directly to the antenna with the SX-117 antenna connection being through the TR switch.? Getting rid of the slow antenna relay made a huge difference.? With the relay, the first dit was so short it could barely be heard and just barely moved the needle on my peak reading wattmeter.? Today with the TR switch, the first dit is substantially longer and clearly audible with a single dit showing up on the wattmeter as full power (100W).? Not perfect, but maybe acceptable.? I see that the August 2018 issue of QST had an article on building a solid-state TR switch and will add that to the project list.? Johnson TR switche are sort of hard to come by these days and finding one without a rusted housing is just about impossible.? I'll scope the first dit later to see exactly how it compares to subsequent dits.
73, Floyd - K8AC
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Re: 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.
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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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Re: SX-100 Repair Problems - Bumblebees!
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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Re: SX-100 Repair Problems - Bumblebees!
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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ok, i sent you an email,..
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im not sure what address you want me to use,, my email is kullom99@...??
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Hi KU,
May be able to help. Send pm to rantidromic at the Google place.
Cheers,
=Randy=
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Looking for an R-274 parts radio, if anyone has a parts unit that they will sell, id be interested,,I need a bunch of stuff, so, thought it might be better to find one, if possible,, need an rf gain/ power switch and knob, audio pot and knob, a dial mask,
the plastic one on the front, a dial marker, that hangs down from the top to show the frequency,? and i could use an entire dial tuning assembly, as this ones literally worn out these are the parts im looking for , thanks, Kim..WV8KU
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Re: SX-100 Repair Problems - Bumblebees!
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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Jacques_VE2JFE
don Root
Floyd - K8AC