Antenna base corrosion

Trikesyke · Nov 28, 2017

I removed (unscrewed) both antennas and discovered the FM base threads were clean where they were covered by the antenna, but rusty where exposed to the elements (I presume). The CB base threads were however, corroded, not rusted, from top to bottom. I realize the corrosion is not good, a non conductor, but I wonder why the antenna did not protect the base like the FM antenna did. Anyone have an idea/answer? Also, would non conductive lubricant grease protect the connection? And how about cleaning the antenna and base threads?

vito · Nov 29, 2017

Trikesyke said:
I removed (unscrewed) both antennas and discovered the FM base threads were clean where they were covered by the antenna, but rusty where exposed to the elements (I presume). The CB base threads were however, corroded, not rusted, from top to bottom. I realize the corrosion is not good, a non conductor, but I wonder why the antenna did not protect the base like the FM antenna did. Anyone have an idea/answer? Also, would non conductive lubricant grease protect the connection? And how about cleaning the antenna and base threads?

A wire brush would clean the antenna. Not sure hot to clean little hole. Grease would help keep it from happening again, Don't worry about conductive or not at the frequencies they work on.

1dn5up · Nov 29, 2017

Use a dab of Die- Electric grease on the threads and screw on, good to go. Do both

Use the grease on butt connectors also.

Trikesyke · Nov 29, 2017

vito said:
A wire brush would clean the antenna. Not sure hot to clean little hole. Grease would help keep it from happening again, Don't worry about conductive or not at the frequencies they work on.

Thanks Vito. Wire brush sounds good. Are you implying that I don't have to clean off the corrosion? I would think there needs to be an electrical metal to metal connection between the base and antenna in order for the antenna to be the 'extension' of the wiring.

Trikesyke · Nov 29, 2017

1dn5up said:
Use a dab of Die- Electric grease on the threads and screw on, good to go. Do both

Use the grease on butt connectors also.

I couldnt think of dielectric. Thanks 1dn. Are you saying the grease will cut through the corrosion?

1dn5up · Nov 30, 2017

Trikesyke said:
I couldnt think of dielectric. Thanks 1dn. Are you saying the grease will cut through the corrosion?

Yup, it’s only brass. If it was that bad you would of struggled to unscrew the antenna.

vito · Nov 30, 2017

Trikesyke said:
Thanks Vito. Wire brush sounds good. Are you implying that I don't have to clean off the corrosion? I would think there needs to be an electrical metal to metal connection between the base and antenna in order for the antenna to be the 'extension' of the wiring.

Metal to metal is best but if insulated by a very thin layer of grease it forms a capacitor that has very little impedance at FM or even CB frequencies - probably not enough to matter. Generally, the first/last thing you'll find inside your radio is a capacitor that's there to protect the rest of the circuits from external voltages.

Trikesyke · Nov 30, 2017

1dn5up said:
Yup, it’s only brass. If it was that bad you would of struggled to unscrew the antenna.

Actually, I did have some difficulty unscrewing the antennas....

Trikesyke · Nov 30, 2017

vito said:
Metal to metal is best but if insulated by a very thin layer of grease it forms a capacitor that has very little impedance at FM or even CB frequencies - probably not enough to matter. Generally, the first/last thing you'll find inside your radio is a capacitor that's there to protect the rest of the circuits from external voltages.

And this is why I wanted to ask on this forum! Thanks vito.

hocnsoc · Dec 5, 2017

Clean internal threads.

Trikesyke said:
And this is why I wanted to ask on this forum! Thanks vito.

If you want to clean internal threads, a small bore gun brush works quite well.

MikeyTX · Dec 5, 2017

1dn5up said:
Use a dab of Die- Electric grease on the threads and screw on, good to go. Do both

Use the grease on butt connectors also.

So true. stuff is great.

vito · Dec 5, 2017

MikeyTX said:
So true. stuff is great.

dielectric grease is an insulator that has a place but that place is not between two conductors that are supposed to pass current. It is good for keeping moisture out of connectors. So is Vaseline.

hogcowboy · Dec 5, 2017

hocnsoc said:
If you want to clean internal threads, a small bore gun brush works quite well.

There ya go. I knew I'd seen a brush that would be perfect for cleaning those threads. Right there in my gun cleaning kit. DUH!!! :facepalm::facepalm::facepalm::gah::gah::gah:

ultrafxr · Dec 5, 2017

vito said:
dielectric grease is an insulator that has a place but that place is not between two conductors that are supposed to pass current. It is good for keeping moisture out of connectors. So is Vaseline.

I agree. I hate the stuff. A friend who is a heavy equipment mechanic with Caterpillar told me they were instructed to NOT use dielectric grease. After a while it dries out, gets hard and sticky and is just a general mess. Keep it clean and dry and you'll be OK.

MikeyTX · Dec 5, 2017

vito said:
dielectric grease is an insulator that has a place but that place is not between two conductors that are supposed to pass current. It is good for keeping moisture out of connectors. So is Vaseline.

Not sure who told you that. There is a reason it is on the base of every damn bulb Harley installs at York. Dielectric grease is used on spark plug terminals, and many other electrical applications because it does not inhibit current flow. Google it !

MikeyTX · Dec 5, 2017

Is Vaseline a good conductor of electricity?

"Petroleum jelly is not a conductor - though it might have very slight conductivity, even air does. It is not a good thing to put on electronics as some wire insulation deteriorates in the presence of grease and oil. It is also messy and I'd expect that if there are high temps present it may melt and leak." Direct quote from a google search.

Trikesyke · Dec 5, 2017

hocnsoc said:
If you want to clean internal threads, a small bore gun brush works quite well.

Thanks Hoc. I'm thinking 9mm isn't the correct size then........

MikeyTX · Dec 5, 2017

A bore brush for the M108 ought to work just fine ....................:yahoo:

vito · Dec 6, 2017

MikeyTX said:
Not sure who told you that. There is a reason it is on the base of every damn bulb Harley installs at York. Dielectric grease is used on spark plug terminals, and many other electrical applications because it does not inhibit current flow. Google it !

We used to use it inside high voltage coaxial RF connectors because other greases would short the inner conductor to the outer. Use is also recommended to prevent 'fretting' where there is vibration. Maker describe it as "electrically neutral" whatever that means. I use it on handlebar switch assemblies of older HDs to keep rain from shorting switches.