I started to paint my new satellite dish because the original paint looked thin and I didn't want it to rust quickly. It was grey and I painted it black - but the spray paint ran out before I could spray all 6 sections, only three panels are black the others are grey. Then we got a technician to set it up, but he could not succeed, and he blames the paint job. Does anybody know if this reason is plausible or not? If I get another can of paint and spray the other 3 sections will it work (the technician said we should buy a new dish!).

Thanks.

Unless the paint is conductive (not an insulator) in some way, it should have no effect on the operation of a receiving antenna.

It's most definately plausible

At microwave frequencies all sorts of things can cause effects you wouldn't expect. There is a reason that the radomes on ships and aircraft have "Do Not Paint' stencilled on them.

That said, I wouldn't expect regular spray paint to have any effect (you did only paint the dish and not the LNB didn't you).

A new dish is not expensive, you may even be able to get replacement segments.

Next time let the man set it up before you do anything to invalidate the warranty

It should have no effect at all. However be sure the LNB and feedhorn were not painted also. Several satellite sites and forums all say this and show pictures of various paint job including a cameflauge version. Also it should be a matt finish and not glossy due to heat reflecting to the horn cap and potentially melting it or heat up the LNB which could cause noise. Also make sure you did not use a lead based paint. One last thing is the coat should be thin. The thicker it is the more chance of absorbing some of the microwave (RF) signal reducing the signal to the pickup.

Can they be sandblasted?