The AM Forum

THE AM BULLETIN BOARD => Technical Forum => Topic started by: Carl WA1KPD on June 16, 2020, 09:14:35 PM



Title: ZINC PASTE (PENETROX) On Coax Fittings
Post by: Carl WA1KPD on June 16, 2020, 09:14:35 PM
Just finished building a 6-meter beam and the manufacturer included some Penetrox tom be used on all metal to metal contacts. Someone told me it was also good to smear inside the PL-259 and SO239 junction to prevent corrosion.
I'm not sure as I understand the purpose is to keep the integrity of the electrical connection. I am concerned that this would cause a short between the inner pin and outer shell.

Does anyone have solid knowledge or experience? Google has not been helpful.


Title: Re: ZINC PASTE (PENETROX) On Coax Fittings
Post by: WA2SQQ on June 16, 2020, 09:58:42 PM
Itís conductive, so apply it sparingly. I always apply a spritz of deoxit, than wrap the connector. Just  checked a connector that was atop the tower for 7 years - still bright and shiney.


Title: Re: ZINC PASTE (PENETROX) On Coax Fittings
Post by: WBear2GCR on June 16, 2020, 11:00:29 PM
I'd personally prefer lead based (hard to find these days) or nickel based... on the outside threads of a PL-259 - SO-239, I think
it would be fine...

Otoh, I've had such a connector pair on dipoles and beams, which I wrapped in black electrical tape, then covered
with that stretchy/rubbery sealant stuff. They sell it, but I got mine from a friend who worked for NY Telephone, and
the later incarnations... When I peeled that off after 20 years, the connectors were bright and clean!

Oddly they seem to sell an "anti-seize" that is aluminum?? Huh? What is that?


                   _-_-bear


Title: Re: ZINC PASTE (PENETROX) On Coax Fittings
Post by: W1ITT on June 17, 2020, 10:16:42 AM
There are different flavors of Penetrox, the regular stuff, Penetrox-A for aluminum, and the copper bearing stuff.  Perhaps there are others.  I have seen evidence of Penetrox-A creeping in warm conditions.  Therefore I'd be cautious about using it in coax connectors, being scared that it would make its way onto the dielectric and either degrade it or provide a shunt path.  My experience with the quart can of Penetrox -A that I acquired decades ago is that one should use about a tenth of what you'd think is necessary, despite the fact that some packagings come with a brush in the cap.  If I were to use it on the threads of coax connectors (which I've never thought necessary) I'd apply it with a toothpick and let the threads carry ti. around.  In general, it's good stuff and I wouldn't want to be without it.

73 de Norm W1ITT


Title: Re: ZINC PASTE (PENETROX) On Coax Fittings
Post by: VE7RF on June 25, 2020, 01:14:53 PM
The only thing  you want to apply is a thin coating of dielectric grease (any auto parts store)
to both the center pin..and the threads, that's it.

Jim  VE7RF
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands