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joecb.
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March 19, 2023 at 12:18 pm #274139
Starting a new thread…. Tubs wrote ..
“They came from eBay. Got them to substitute the condenser in a poinion
as has been a topic here from some time. They didn’t work. Went back to
condensers as I know what to buy.”Tubs, I know that you are really good about working “fixes” out to final results, so what is with this “did not work” ?
I have had great success with substituting metal foil caps for the old paper capacitors. I have friends the swear by the substitute ,claims they will fix any ill magneto.
We use the Vishay #1839 HQ .22mf 850 Volt metal foil caps. I have found that .22 mf to be just about a universal fit.
Joe B
March 19, 2023 at 2:30 pm #274141when I use caps I use at least 600v minimum.
March 19, 2023 at 8:19 pm #274165I purchased theseto refill cans as per M.Mohat process. I haven’t tried them in real life but they are rated 630v
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March 20, 2023 at 12:09 pm #274188
Responding to Joe B. I was acquiring a lot of Super Elto’s and
they all need the wiring repaired. The coil and the condenser
are in a tube filled with tar. I had figured out how to get the coil
out, clean it up and reuse it but the condenser needed to be
replaced.
Its value is .1mf. I stumbled on to these. They exceeded the 600
volts that was being recommended. I posted them on the board
and asked if they would work before I ordered them and the
response was, they would.
When I tried one of these 1mf caps. I bench tested the assembly
before I filled the tube with wax. The coil would fire on the bench
but the motor wouldn’t run.
I took the coil out again and replaced the cap with a condenser
and it took right off.
Posted my experience and Tom Manley had an explanation that
made sense to me. He said – that condensers have a dV/dT
specification. Dumbing it down for me, the condenser wasn’t fast
enough. That would coincide (in my mind anyway) why it would
fire on the bench but motor wouldn’t run. He gave what the min.
spec. needs to be, and I have it some were, but its something you
would have to search out before you buy.
So its more than just the mf value and the voltage.
Now that I throw the original coil away and use a substitute who
knows what the correct condenser value would be. I have a few
that I favor but its more about how the fit. I can get most of the
ones I prefer at any auto parts store.
It was expanded to me that having the wrong condenser value can
accelerate the point wear but other things can change the actual value
at the points like, the length of the wire, poor connection at the wire,
or a poor ground. All can cause the points to pit prematurely but as
little as these motors get run you probably never notice it. So far that
has worked for me and I believe I run my motors more that most.
Tubs.
A "Boathouse Repair" is one that done without having tools or the skills to do it properly.
March 20, 2023 at 12:40 pm #274189Per Mr Mohat’s suggestion, I also tried these ceramic capacitors:
Murata KRM55TR73A224MH01K
This particular number is 0.22 uF, but the are available in 0.10, 0.15, and 0.33 uF also. I am unable to find the dV/dt rating for these capacitors. They are a little less than $3 each. You need to solder leads to them, but they are very small and can be used to rebuild all sorts of condensers. The ones with the brass cans, like WICO and some used on Mercury MK motors are really easy to do.
Tom
March 20, 2023 at 12:45 pm #274190I have some of those small ceramic caps … got to find them in the bin somewhere 🙁 and try them out
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March 20, 2023 at 2:18 pm #274197Just a word of caution here but beware if buying capacitors or any electronic components off Amazon or that big auction site as they are well known for selling fakes cleverly disguised as being genuine. It’s always best to spend a bit more and purchase from one of the major suppliers such as Mouser, Digi-Key, or Newark etc. That way you know you will be getting the real McCoy and not a counterfeit dressed up to look like the original.
Also, study the data sheets for the capacitors as some of them are SMD’s (Surface Mount Devices) and can be extremely small requiring special skill and equipment to install them.
March 20, 2023 at 2:58 pm #274200nothing new under the sun… remember those early 5-6 -7 transistor radios with most of the transistor legs all soldered under the board… yes the radios had 5-6-7 transistors
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March 20, 2023 at 5:47 pm #274214See this thread:
https://www.aomci.org/forums/topic/condenser-can-stuffers/page/2/
The Vishays work well.
March 20, 2023 at 6:38 pm #274221Another thread about the Vishay caps.
https://www.aomci.org/forums/topic/substituting-old-condensers-with-modern-capacitors/
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