CB antenna prob?? (1 Viewer)

Joined
Sep 3, 2007
Messages
4,432
Location
Longmont, CO
 
 
I've got a CB in my 40 and I can't hear anybody! Granted, I wouldn't imagine the CA bay area has high CB traffic given that its at the end of the interstates, but I've been listening and mike-checking on 19 for a couple days during my commute and am getting not a peep.

I'm wondering if my antenna is the problem - I'm not a radio guru, so bear with me.

My antenna is mounted on the rear of the truck, on the tire carrier. There is paint in the way of a good ground path (its a rear-view-mirror-clamp-on-job), so I ran a ground wire from the antenna bracket to the body to ground it out. The antenna itself is a 2foot fiberglass whip, at the rear left corner of the truck - it protrudes a lil bit above the highest metal parts of the hardtop, and is sitting directly in front of the corner window. I thought this would be a good location given the restrictions imposed by the height of my garage, have good visibility, etc.

Anyway, before I added the ground wire I heard some spanish being spoken on on ch10 (barely, mind you) but that was it - I thought adding the wire would put me in the clear. But nope, didn't help, I haven't heard anyone for days now. Since I don't know what I'm doing, I've been trying it manually squelching up and down as well as with the automatic "DSC" thing on. RF gain set at 50%, because i dunno how to really set that guy.

Weatherband works fine, great even.

Ideas?
 
Joined
Dec 2, 2004
Messages
1,601
 
 
 
Don't know what you have in the way of a radio and antenna, but you can start by turning squelch off and the RF gain up to max. Check if there is a mic gain, turn that up as well.
 
Joined
Sep 3, 2007
Messages
4,432
Location
Longmont, CO
 
 
Joined
Jan 12, 2006
Messages
1,107
Location
St. Louis, MO
 
 
At a minimum, you need to connect an SWR meter in-line with the antenna and get a reading. This will let you know what direction to go (you could have a ground short somewhere, or just a badly tuned antenna - or excellent setup with just no traffic around, but I doubt the last option).

I wouldn't transmit without testing the SWR as you could damage the radio (though not real likely if you're operating at the legal limit).

The SWR meter can be had for ~$20 but you might see if you can find someone local who will help you use it (and let you borrow their meter!).

Good luck!
 

uHu

Bridgeburner
Joined
Nov 27, 2005
Messages
2,045
Location
Oslo, Norway
 
 
 
Vehicle CB antennas are of the GP (Ground Plane) design. That means they have to be mounted directly on a large sheet of conductive material which is a part of the vehicle. Only good place is on the roof or on a wing a bit away from any pillar. If you put it on top of the wheel carrier, or ground it with a cable, the heigth of that grounding will count as a part of the antenna lenght and the antenna will not be in tune anymore. You can get antennas which are not GP, which you can mount anywhere (like on a pole, a boat or a house).
If your hardtop is of steel, and well grounded to the rest of the body, I imagine the best would be to put an antenna up there. There are antennas with a spring at the base so that they bend without breaking in case you forget to fold it down before "garaging".
Anyhow, SWR (Standing Wave Ratio (= Reflected Power)) metering is a must.
 

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