Magnetic mount CB antenna on outside AC unit, good ground?

Question

i have a base CB radio and a couple of magnetic mount CB antennas that i used for cars. i want to use the mobile magnetic mount for my base CB radio. if i place the magnetic mount antenna on my A/C unit that is outside on a concrete slab. will this give me a good ground plane to use the antenna? i don't want to burn out my radio. i would like to use this mount because i have a couple of them and they work great on my car. OR how about if i pound in a metal rod (1/4 OD) alteast 3 ft in the ground and mount the antenna to it?

Answer 1

you want the antennae up high off the ground to give you the best distance range.

Howabout  the roof?

Like this: antennae,,,steel plate,,,wire to the ground rod--6 feet deep.

Answer 2

You don't want to put a whip on the roof and run a wire down to a ground rod.  That "ground" may be a dc ground, but to rf it could be anything from a "ground" to an open, depending upon the length of the wire running between the antenna and the ground rod.

This is why folks use ground planes.  You've seen 'em, with perhaps 4 rods extending from the base of the antenna (mounted on a tower or on the roof) out several feet.  They act as an artificial ground and that technique works quite well.  Of course, you could simply buy a ground plane in the first place!

The other option would be to mount two mag-mounts back to back and form a dipole.  This could be mounted vertically and you'd have a half-wave antenna.  The shield side of the coax would feed one and the inner conductor would feed the other.  Coil a few turns of the coax a foot away or so and the coil will prevent the rf from returning via the outside of the coax.  It will feed the other whip.

Best regards,

Jim

ps - you can take a length of coax, strip off the last 102 inches of shield and inner insulator, go back another 102 inches or so and form the loop (perhaps 2-3 turns of coax a couple of feet in diameter).  You now have a dipole.  Simply move (by coiling up or down) the loop a bit and adjust for minimum SWR.  No ground necessary.  Notice that neither the Dish Network nor Direct Tv require a ground on their satellites nor on their dishes (other than a safety ground)

Answer 3

its good to talk to another cber. i have 1 in my car and a k-40 antenna.it should ground there. if your in doubt, go ahead and put it there and hook up a meter to it and see if it goes in the red, if it does, run a piece of wire from the antenna to a copper rod in the ground.

Answer 4

Try it out!

If it does not work well, ground it out

Answer 5

I think that having the antenna stuck to the A/C unit would cause some interference from the inductive motor inside the unit. You probably wont notice it much for close range communication, but will affect comms over a distance.

You would be better off placing the antenna away from the A/C unit.