MB:
Higgler (Electrical)
Well,
As an antenna engineer with some great test
equipment, if anyone wants to send me a painted and non painted antenna, a simple test takes just 10 minutes and it's easy to do, and I won't charge you anything (other than return shipping). You could also send me the paint for loss tests, that'll cost you a bit, I'd have to make a test setup special.
In general, low frequency wider
bandwidth antennas can be painted with most non metallic paints and you'll never see the difference.
The worst antenna to paint is a narrow band antenna (
GPS antenna is best example) using a thick paint coating. It'll shift the frequency downward and not work in your frequency band anymore.
Narrow bandwidth (typically thin antennas = narrow bandwidth) antennas, if designed properly should have a thick radome so that multiple thick paint coatings (or rain/ice) will be far enough away from the metal radiating part of the antenna to be out of the field.
On the same thought pattern, water is dielectric = 81, and very high loss, much much higher than 99.999% of all paints. That's the worst paint equivalent (other than metallic paint) that you can imagine. If it works in the rain, generally it'll work with a little extra paint on it.
kchiggins
Toyon Research Corporation
Antenna Group.
Metallic paint has a high dielectric constant (Basically, it provides a barrier between
the electromagnetic waves and your antenna). Painting an antenna protects the antenna from the elements and painting it is also for appearance. That is basically the reason to paint it.