WILSON 2000 trucker

At least an 8 gauge wire from the antenna mount to the frame. If your using a mag mount then your mag is not pulling enough ground from the body of your truck and you need to go to a bigger mag mount.

 

Brian,
Is there any chance that the hot part of your mount (the 3/8x24 where your antenna threads into the base) is shorted to ground? If you've got an ohmmeter, set it for ohms and put one lead on the hot, and the other lead to ground (like the sheet metal of the roof). Alternatively, just unscrew the coax connector from the radio and read between the center pin and the shell. If you show essentially *any* numbers, or all zeroes, your system is shorted, and no amount of adjusting of the antenna's length will fix it.
3 checks to do on any coax after an installation:
1) Center pin to shell: should show infinite resistance, meaning not connected to one another;
2) Center pin on plug to the hot part of the mount, where the whip screws in: should show 0 ohms or very close to it;
3) Outer shell of coax plug to ground, ideally at the mount: should show 0 ohms, or very close to it

If any of these three conditions are not met, you already have an antenna feed system fault, and need to fix it before you go any further.

When I do an install, I always do these checks *before* I install the connector on the "radio end" of the coax. That way, if I've got a braid strand shorting at the mount, or a pinched coax going through a body panel or someplace, I can fix it right then. If I waited until after I'd put on the PL-259 connector, I wouldn't be able to tell where the fault was (sometimes plug installations go awry).

All this assumes that your GMC pickup's roof is metal; if it's some sorta Jimmy or something with a plastic roof, you'll have to change antennas or install ground plane foil on the underside of the roof.

Hope that helps,
-- Handlebar in NC --

 

Statesville NC? Im an Ex Alexander county boy myself. You run a base at home? May have talked to you at some point.

 

Yuppers, and don't think so, in that order, unless you're also on 2M or 75M.
I only moved here about a year ago, and have only a modest antenna up at the homestead.

I only know of Alexander County cuz their jail had an escapee two days ago, and a horde of police officers caught him in the woods half-a-mile from the house after a 4-hour search with doggies.

Clearly, I've gotta get out more And spend more time with a map

Just in case, though, I use Handlebar as my -- excuse the term -- handle, mostly on 19 & 22.

73,

-- Han.... ah, you already know --

 

Yuppers, and don't think so, in that order, unless you're also on 2M or 75M.
I only moved here about a year ago, and have only a modest antenna up at the homestead.

I only know of Alexander County cuz their jail had an escape two days ago, and a horde of police officers caught the miscreant lad in the woods a half-mile from the house after a 4-hour search with doggies.

Clearly, I've gotta get out more And spend more time with a map

Just in case, though, I use Handlebar as my -- excuse the term -- handle, mostly on 19 & 22.

73,

-- Han.... ah, you already know --