CB issues

[m0th]

Getting high SWR  on a new CB install. Not pegging, but over 3.0 on all channels. Bad ground maybe? Anything else I should be looking at?

[Elsifer]

Getting high SWR  on a new CB install. Not pegging, but over 3.0 on all channels. Bad ground maybe? Anything else I should be looking at?

If the antenna is tuneable, try the moving the tip in/out.
The ground for the antenna only matters if the antenna length is less that 5/8ths of a wave. CB is 11m wavelength, so an antenna under 6.875 meters in length will need grounding to make an adequate counterpoise. But be careful. Just because the antenna isn't that long, doesnt mean the radiating wire element isnt coiled around many many times around the fibreglass rod. You antenna documentation will give you the radiating length.

Also, check your length of feedline to the antenna.

Good writeups on radio's here:
http://www.stu-offroad.com/misc.asp

[m0th]

Thanks - some good links there.

Yeah, it's tunable - a 4' Firestik Firefly. Haven't even tried tuning it because I thought over 3 was more likely something wrong with the install and got worried I might destroy the radio 

Checked all the connections this morning. All looks good. Might just pull the Wilson antenna off the Liberty and see what it's like with that one.

[FiEND]

if it is a ground issue, it tends to pin the needle (into the red).

on a tj, 3 SWR is average when mounted to the back, i've seen better and worse bit typically 3.  especially with a hardtop on.  if it is 3, it's not bad and i'd live with it - 75% power isn't all that bad for a rear mounted antenna.

http://www.firestik.com/Tech_Docs.htm is another good site.

[m0th]

That's the site I had been using Al. Some good diagrams there for the clueless like me. 

Anyway, after realising my voltmeter was b0rked (at least I think the red probe is supposed to stay attached to the red lead  ) I went back and checked all the connections AGAIN. Seemed ok, but just for good measure I reached inside the tub and gave it a good sanding, reconnected everything and now its in the mid 1s on 1 and 20 and the mid 2s on 40. Going to take out somewhere away from the house tomorrow and tune it properly.

[Yellow RUBI]

For mobile instalations, ground is a huge factor. As you have just learned it is very important to make sure you antenna mount is well grounded and that your stud mount is tight but not over[tight.
Any SWR over 2 should be thought of as unacceptable and will reduce your range and the life of your radio!
Make sure when you tune your antenna you are well away from buildings and larger vehicles, (an empty parking lot is best).