Batboard

Pretty much as it says. I am doing a custom job; I have a L band sat dish that I am modifying. It has a fiberglass radome in marine white, I need it to be a little more inconspicuous. Can I paint this a flat color like black, and if I can, what kind of paint can I use that won't kill the RF?

Thanks,

-Shawn

OK, Shawn, the main thing you have to worry about is the RF conductivity of the paint you choose. Its fairly easy to check. Just put a sample of your chosen paint in a microwave-safe container (I'm assuming you're intelligent enough to know better, but just in case, DO NOT!!! put an aerosol spray can in a microwave!), and put it in a microwave along with a small cup of water (the microwave needs something for a load), and nuke it for a minute or two. If your paint sample gets warm at all, its RF conductive. If its RF conductive, you may as well wrap tinfoil around the antenna. If its not, you should be OK. Good luck!

THAT sounds like a GREAT idea! Thanks much!

-Shawn

kf4sqb wrote:OK, Shawn, the main thing you have to worry about is the RF conductivity of the paint you choose. Its fairly easy to check. Just put a sample of your chosen paint in a microwave-safe container (I'm assuming you're intelligent enough to know better, but just in case, DO NOT!!! put an aerosol spray can in a microwave!), and put it in a microwave along with a small cup of water (the microwave needs something for a load), and nuke it for a minute or two. If your paint sample gets warm at all, its RF conductive. If its RF conductive, you may as well wrap tinfoil around the antenna. If its not, you should be OK. Good luck!

You sound like the kind of person that could be seen on AFV or Country Fried Home Videos. BUt someone has to try all these hairbrained ideas. I hay have to try that myself.

dbfd588 wrote:You sound like the kind of person that could be seen on AFV or Country Fried Home Videos. BUt someone has to try all these hairbrained ideas. I hay have to try that myself.

Gee, that was polite.

This Board just gets better and better all the time, as well as
more entertaining.

Before you denounce my method, stop for a moment and think about it. What is a microwave oven? A large, high-powered radio transmitter (around 2.2 GHz, if memory serves). It heats a substance by exciting the substance's molecules. For it to excite the molecules of a substance, that substance has to be conductive at RF frequencies. Does it not, therefore, stand to reason that if it doesn't heat a given substance, that substance isn't conductive at RF frequencies? If you want proof, try this:

Put a sample of standard Carlon PVC water pipe (the white stuff) in a microwave as detailed earlier. It will get hot, because Carlon uses Titanium Dioxide as a pigment. Being a metal, Titanium Dioxide is conductive. Now, try the same experiment with a sample of SilverLine PVC (if you can find any). I have no idea what SilverLine uses for a pigment, but it isn't Titanium Dioxide. Whatever it is, it isn't conductive, and it doesn't get hot. There may be others besides SilverLine, but its the only one I know of.

BTW, an RF engineer told me about this little trick. Care to argue with him?