"John Doe" wrote in message
...
If you can't contribute anything positive to this question, then stay out
of it, with your trash!

I have a 10m base loaded mag mount antenna, that I had to put a piece of
felt over the magnet as not to scratch a new vehicle.

When I did this I apparently changed the capacitance between the mag mount
and the roof of the vehicle. Someone suggested that I might want to
replace the felt with either a large balloon or a large prophylactic as it
is thinner and the capacitance would then return to almost where it should
be.

Positive comments only!

John

I would have thought that the felt would make the mag mount more likely to
slip against the roof. You might not get any scratches, but you probably
would be minus one antenna at the end of a fast drive.

I have had good results using strips of insulating tape or adhesive backed
plastic type materials, similar to the stuff they print stickers on covering
the magnet. For best results, you want a soft resiliant type of plastic,
something that wont slip against the roof metal. Or have a look for some of
that plastic sheet that sticks to glass and smooth surfaces and is used to
secure licence or insurance details to car windscreens. That should protect
your paintwork and be removable at a moments notice. A favourite trick for
mincab or unlicensed cab drivers is to cover the antenna base with a stout
sandwich bag and secure it in place with a plastic tie wrap. Take the
antenna off the roof and no traces left behind.

Any of the above methods should work okay and they will all be a lot thinner
than a piece of felt.

Mike G0ULI