How to test an antenna

[cabezon]

I bought a used rv and it has a 4' fiberglass antenna. I put a cb on it and a get 1.5 on the swr meter. I can only very faintly hear anything and when I call out I get no response. I tried four different radios on it and all get the same results. Is there a way to test the antenna with your standard electrical meter? I'm going to by a Wilson 1000 for my Galaxy 88 that is in the shop but I would like something for now just to put one of my cheap CBs on. Lee

['Doc]

I think you've pretty well tested it already. It seems to be acceptable to your radios, but that certainly doesn't say how well it's working. Are there any others near you that you could check it with? I think that could tell you more than a few random calls.
- 'Doc

[grandpaclint]

i assume the R.V you got is fiberglass, and not aluminum like my Camper.
You need to get an antenna with its own groundplane,same as used on a boat.
I think wilson makes a ground plane kit,i saw it awhile back.
you might look that up.

Doc knows all about that stuff.

['Doc]

grandpaclint,
I really do appreciate the 'flowers', but I certainly do NOT know about all this stuff. I've 'played' with antennas for a long time, I think it's fun, and I've made a huge number of mistakes having all that fun. Some of them I remember after making them enough times, and those I'll usually tell people about if it applies to what is asked.
- 'Doc

(Me and old Einstien really do have several things in common! Gray hair and bad taste in sweaters being the biggies.)

[cabezon]

The roof is alunimum,the antenna is mounted onthe edge of the roof. I was receiving some skip and some faint local talk. I tried to get a radio check on the local channel and got no response. I hooked up a 250w amp and when I keyed up the power meter barely moved. I have high voltage power lines about 30-40 ft directly above me and low voltage about 8ft above my roof. It's mounted on metal, but I will check the ground later. Thanks for the replies. Lee

[cabezon]

Update. checked my power supply and getting low voltage,11.5 and 10.9 when xmiting. I cleaned the battery connections and put a charger on them. Now I'm getting a ton of static with the charger on. Atleast the voltage is now good. I tested the SWRs with the good voltage and they are 2.5 -3+. Seems the antenna is not so good. I see no way to adjust it. Again, thanks for the input. With every trial comes learning. Lee

['Doc]

I think your next step is to tune that antenna. there are three basic ways of 'tuning' a fiberglass antenna. Some have an adjustable 'screw' or whip on the top. Some you pull the plastic cap off of the tip and look inside for a sort of loose wire. Adjusting the length of that 'loose wire' can tune that antenna. And then there are the ones with no means of adjusting length except to cut the thing off (-IF- needed!). Lots of "if's/and's/but's" in that, just depends on the antenna. No idea how yours is.
- 'Doc

[rattlesnake]

A swr meter