The AM Forum

THE AM BULLETIN BOARD => Technical Forum => Topic started by: W9BHI on May 24, 2014, 09:49:23 PM



Title: Polarity of oil cap
Post by: W9BHI on May 24, 2014, 09:49:23 PM
I have a General Electric Pyranol capacitor  CAT 23F406  8MUF  3000VDC.
It is for a Johnson DKW.
It was removed when I got it and has no polarity markings on it.
Any ideas on how to identify the polarity of the terminals or doesn't it matter since they are both insulated from the case.

Thanks,
Don W9BHI


Title: Re: Polarity of oil cap
Post by: WQ9E on May 24, 2014, 09:54:02 PM
Don,

With  rare exception oil caps don't have a polarity orientation and the one in the Desk KW certainly doesn't.  The only time I have seen a polarized oil cap was in a piece of mil gear where the case itself was the ground terminal and I think it was designed that way to fit in the minimum space possible.

By the way, be very careful feeding the cables when sliding the mainframe into the pedestal because it is easy to crimp a coax cable.  I believe I have already cautioned you about doing something about reinforcing the bottom rails in the pedestal to prevent them from spreading which would then result in a stuck mainframe with no way to pull it back out short of metal cutting.  That has happened to at least two Desk KW owners.


Title: Re: Polarity of oil cap
Post by: W9BHI on May 24, 2014, 10:29:13 PM
Thanks Rodger,
Now I can get that reinstalled in the unit.
I am going to install threaded rods between the lower rails in 3 places.
That should keep the rails from spreading.
Don W9BHI


Title: Re: Polarity of oil cap
Post by: KA0HCP on May 25, 2014, 12:54:36 AM
BTW, Pyranol caps have PCB oils, so wash your hands after handling them and avoid any touching any leakage.
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands