Painting an antenna? Bad idea?

Yes. Smog interferes with it also. However not by much - would it be a transmitter - no big deal - a feeble signal receiver most likely.

Martin

Wow - used to consult with that group - 24 years ago has it been - Phew! Flew all over the U.S. installing computer systems for REA power / load control. Naturally it drove at least one Motorola transmitter.

Martin

Except for the fact that the skin is deeper for less conductive materials, the extreme being fully nonconductive materials like vacuum, where no skin travels (not counting electron emissions, but that's not a bulk conduction sort of mode). Or rather, I should say, the skin depth is full, being the electric field continues across it.

Which brings me to another point: insulation won't harm anything, because the electric field across the paint will be very low. (Most of the E-field 'voltage drop' occurs across the air.) To AC, an insulator of high dielectric constant (plastics go from say 2 to 10, paint might be 3 to 6, SWAG) looks like another piece of wire.

The worst combination would be a paint which has the right resistivity that a large portion of the current flows in it, while still being resistive to it. About analogous to stealth radar-absorbent material, but for your antenna (and at lower frequency). But since this layer is much thinner, especially with respect to the wavelength, I sincerely doubt you'll notice any difference whether the paint is a perfect insulator, resistor or conductor.

Tim

-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @

Thanks for your help. I have been leanign toward the ground plane but have been confused at some of the articles I have been reading:

I have a radio shack antenna book that has a saple plan for building a small wire antenna directly to a pl connector. It says that radials for a ground plane are bent to determine the antenna's impedance. But I have seen some that were not bent.

I would like to build something I would not have to fool with once it is up because I plan to put it high atop my tv antenna tower and I am not crazy about heights!

The other thing that bothers me about a ground plane is I have not seen any plans for a dual band version and I would also like to get on 440. By the way, I have my license.

It always warms the heart to see a troll's attempt get short-circuited.

Ok, I'm sure that the right thing to do is get it right the first time. Have fun on your quest! I also enjoy the book/reading side of several hobbies. For me, that's a large part of my hobby life. The book/learning thing is a whole different track than my comments about getting something working. I'd be tempted to just buy a dual band vertical at one of the ham sites, or swap meets around whereever you are, and mount that on the tower.

I don't know of any DIY's that don't need a bit of tweeking/tuning to get working, or at least not with me putting them together.

If it's about $$, the ground plane bothers you, and you only want to go up the tower once, I'm out of suggestions, perhaps TV? but I still stand by my statement of having fun!

Forgive my ignorance, but what is a "indexing jig" I wonder if I could make a discone that would be an all bander. I have plans for a uhf copper discone. I wonder if I could modify it to cover vhf too. I wonder if I could use aluminum elements instead of all copper flashing? WOuld there be a difference in performance?

If you google for "indexing jig" you will be enlightened. Don't forget the quote marks.