Painting an antenna

[Tinariwen]

hi

i have build a 4G lte yagi antenna with cooper

and to prevent copper corrosion i will use non conductive spray paint

does spray painting an antenna have any impact on the signal quality ?

thank you

 

[ChrisABQ]

I don't believe it does, but I would use a clear coat rather than paint.

 

[jonwienke]

It can, especially if the paint has conductive ingredients. Minimize the thickness of the paint or clearcoat layer to minimize potential effects on performance.

 

[cpetraglia]

You can test the paint you plan to use. Spray a decent amount on a piece of cardboard. Let it dry completely. Place in microwave and if it does not heat up, your good to go. It has to be dry(cured) before you test it !

 

[Tinariwen]

Thank you very much for the information

 

[prcguy]

I've painted probably 100 VHF and UHF antennas and have never seen a problem. I've even tested Ku and Ka band satellite feed radomes with various spray paints and some have very little effect with just one coat. Others attenuate a lot, but painting a plastic radome is a little different than painting a metal antenna.

One thing that does happen is a coating of paint or anything on a metal antenna will cause it to resonate slightly lower in frequency because you are going from a bare metal radiator to one that has a dialectic coating. Its the same effect when going from a bare wire antenna for HF compared to using insulated wire and the effects from that can be several inch differences in wire lengths.

I'm not sure if you will notice on a small Yagi but on long lengths of wire its very noticeable.
prcguy

 

[AI7PM]

Use Krylon paint. It doesnt affect RF.

 

[Tinariwen]

ok now my antenna is painted with a thin coat of non-conductive paint (abro white)

and no difference in performance....