MOLDY CAPACITORS

[loosecannon]

thanks for the info CK.

I do wonder if this substance is forming on the outside of the cap or whether it is coming from inside the cap, and attaching itself by static electricity as Robb suggested.

in the video, Mike shows a crack in the capacitors that have the white powder on them.

this is very intriguing.
LC

 

[Captain Kilowatt]

I wouldn't think there would be much static INSIDE a radio chassis especially in humid environments. Usually the problem is just the opposite, too much humidity along with large temperature swings like we have in the spring and fall here in the Northeast, something those desert dwellers out west don't understand.

 

[loosecannon]

LOL! no, i guess we don't. to us, going from 59 degrees to 89 degrees in the same week is a big temp. shift.
LC

 

[Robb]

I cannot reason why there is powder - that looks the same as the internals of those caps - found only on the outside of the same. Other than a static charge, I cannot see another mechanism that could be responsible. Thoughts?

Yes; the West Coast is a desert climate. Actually referred to as a "Mediterranean Climate". Humidity here rarely reaches 30%

 

[Captain Kilowatt]

Yes; the West Coast is a desert climate. Actually referred to as a "Mediterranean Climate". Humidity here rarely reaches 30%

Humidity here in Nova Scotia rarely gets down to 30% except in the dead of winter. We have what is called a Maritime Climate hence we are one of the so-called Maritime provinces. It never gets nearly as cold as inland regions like Ontario or the mid-western states nor does it get nearly as hot as those same regions. Rare is the day it gets below zero F or higher than 80-85F but we get some pretty wild swings in the spring and fall. It is common to wake up to a heavy frost and be a few degrees below freezing and be wearing short pants and sandals by mid/late afternoon when it is in the 70's. In the early spring/late fall mobile radios are subjected to sub-freezing temps at night followed by very high temps in the day when the vehicle is parked with the windows closed. This makes for some pretty wild swings in temps which also results in high humidity levels inside chassis. I have seen the cases and meter panels sweat when the heater is turned on high during the winter when the radio is frozen cold and the heater heats the vehicle up quickly.The metal cased IF and RF transformers will be damp/wet from condensation at times. Whenever I used to bring my FT-857 in from the vehicle during winter I would always wrap it in a heavy towel first and let it sit for an hour or more at room temp before unwrapping it so that condensation would not form on/inside it from the sudden and dramatic temp change.