Topic: CB is off on sick time- AGAIN, BUT FIXED IN A JIFFY

[Maraakate]

Wasn’t recommending you dissect a good condenser, merely the failed one.

Understood, but to do a full blown comparo, like the oil filter comparo, the whole variety of manufacturers should be covered. Probably need more sophisticated test equipment than what I have, and some material ID skills that I don't have for the insulating paper/film.

Hondaman ignition

Might be on my wish list for a Christmas gift.

The TEC condensers measured .273uF, even the bad Daiichi measured .21uF

I think I can make out a TEC logo on the DSS part photo:

Measuring condensors with a capacitor checker may be useless.  Depending on the voltage rating of this cap (if it's anything over 16V) you may need an old school tube-based capacitor checker.  Heat will affect the capacitance reading as well.  The capacitor checks sold today are meant for low voltage electronics.  They do make ESR meters which apparently are more accurate but I have never used one and probably wouldn't trust the cheap ones on Amazon.

[Kevin D]

Wasn’t recommending you dissect a good condenser, merely the failed one.

Understood, but to do a full blown comparo, like the oil filter comparo, the whole variety of manufacturers should be covered. Probably need more sophisticated test equipment than what I have, and some material ID skills that I don't have for the insulating paper/film.

Hondaman ignition

Might be on my wish list for a Christmas gift.

The TEC condensers measured .273uF, even the bad Daiichi measured .21uF

I think I can make out a TEC logo on the DSS part photo:

Measuring condensors with a capacitor checker may be useless.  Depending on the voltage rating of this cap (if it's anything over 16V) you may need an old school tube-based capacitor checker.  Heat will affect the capacitance reading as well.  The capacitor checks sold today are meant for low voltage electronics.  They do make ESR meters which apparently are more accurate but I have never used one and probably wouldn't trust the cheap ones on Amazon.

 I much prefer riding my CB as opposed to working on it. Im just giving this some extra attention because I have had NO failures in 46 years and two failures in the last three years.... and I have read about other condenser failures here at SOHC4.
 I'm using a Fluke 87 that has a capacitance setting and I'm measuring about .25uF +/- on any condenser that I have, even the failed ones, so the Fluke isn't pushing the condenser hard enough. Maybe put the condenser in the oven at 250f for 1/2 hr and repeat tests.
  The new "genuine" replacements that I got were indeed TEK, Honda p/n 30250-300-154, $23 each, and the CB is running very well with them installed.  I won't have another daiichi anything. I'm going to un-can the failed condenser and have a look at it. But I believe these companies have forgotten how to make a proper condenser. Is it only vintage equipment that uses such a condenser?

[Maraakate]

I still don't know what the voltage rating is of these condensors.  Are they 12V-16V?  Are they higher like 500V?  They are large caps, so I'm assuming they are greater than 25V but I don't have one in front of me or the specs so I have no idea.

I normally deal with vintage mopeds, but like to keep a few 70s Hondas around.  With that said... I have only ever had one condensor go bad, and it was on a moped.  What would happen is the bike ran great for about 5-10 minutes then would die.  I'd have to wait another 5 minutes before it would run again.  The heat changes the capacitance and then does nothing.  If this bothers you, at least on mopeds, you can mount the condensors externally.  This is what I've done for some mopeds and have never had a condensor go bad after doing such a thing.  This may help the cheap/unreliable condensors live much longer.

In any case, if you're serious about testing condensors you really need to get something like an old Heathkit Capacitor Checker.  These are tube based, but easy to restore.  There's like maybe 4 electrolytic caps in them so they are cheap to get them going again.  They have a wide range of high voltages and can even test leakage.

I just saw earlier there is a mention of 630V.  That fluke tester will not be able to stress it anywhere near those specs.  Again, you really need that Heathkit Capacitor Tester if you really want to test it properly.  For those interested, if the bike has sat an incredibly long time you can "reform" capacitors.  Results are mixed, but basically you would use a variac or the capacitor tester and leave it 5v for a few hours, then 10v, and so on and it takes a few days.  May be worth it to you but usually it's way cheaper and easier to just replace the cap.

[Kevin D]

I have disassembled the Daiichi condenser and I didn't find anything notable, but here is what I found:
About 10 feet of film backed (AL?) foil, spooled inside the can
The film measured .001"
The film + the foil measured .002".

It would have come out with the 12 v lead attached if I had ground the rolled edge off instead of trying to pull the rubber plug out.

[Maraakate]

Yes, you won't find anything interesting in there.  It's just foil with some dielectric.  Depending on what they used the dielectric might have even smelled kind of "fishy"!

[RAFster122s]

I expected you to find a breech in the dielectric film.
It would have been nice to see evidence of arcing between layers or breech between layers compromising the capacitance value.

[Maraakate]

Yeah, it's hard to say.  We're positive it is a condensor issue?  It may be possible the simple fact of swapping them out has "disturbed" the connectors and that's the real issue at hand as opposed to the condensors themselves.

With that said, depending on how nuts you want to get... you could get a very large non-polarized cap of the same (or similar) value from mouser or digikey.  Volting rating must be the same or higher.  You would have to mount it external.  It likely would be large and $$$.  Like $40-$50 if you can find something that matches.  But ceramic caps can withstand some serious abuse and "practically" never go bad.  I say practically because it's so incredibly rare for a ceramic to go bad that almost nobody tests them or replaces them in other types of equipment.

You can also find an electrolytic rated for the same specs that is automotive grade and can handle at least 105C.  From there you can "re-stuff" the can if the dimensions are smaller (they probably are).  I work on antique radios as well, and some of the antique radio guys do this when they need the outer shell or want to keep a stock appearance.  Panasonic makes amazing electrolytics that can do 105C, some even 125C rated.  For a few cents to a couple of dollars more as opposed to 85C.  This will be overkill for the application, but will last much longer.  Panasonics just seem to last way past their expected life output as well.

What are the dimensions and voltage rating of the condensor?  I could look up possible replacements if you want to restuff the cap.  See https://antiqueradio.org/recap.htm#replacing and go to the "To Hide or Not To Hide" section to see how to restuff a cap.

[Maraakate]

https://www.mouser.com/Passive-Components/Capacitors/Film-Capacitors/_/N-9x371?P=1z0wqtp

Film capacitors, which means they are non-polarized.  There is 630VDC and 650VAC.  Not sure if this is VDC or VAC as the 630V rating you mention.  Any of these may or may not work if you want to experiment with finding something better.  RMS rating may affect their ability to withstand the load.  But, I'm unsure what the original specs were.

I checked the electrolytics and nobody has anything over 400V any more.  You'd need to go to antique electronic supply to find something if you want polarized electrolytics.