    
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 2499
Registered: 9-2004
| | Posted on Thursday, April 19, 2007 - 12:28 am: | 
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you are not thinking about the right type of grounding.
yes, your antenna is DC grounded just fine, but what you should be concerned with is the RF ground.
all mobile antennas require a ground "plane" as a counterpoise to work properly.
the word "plane" is important here because thats what a car body provides; a big horizontal groundplane.
when you put the 102" whip 2" above the roof, where is the mount attatched at?
is it welded right to the cab above the glass?
is it a vertical "mast" of some sort, with the bottom being somewhere in the bed?
if its this one, thats where your problems lie.
what your antenna wants is a direct connection from the shield of your coax at the connector to the vehicle body.
any lengths of wire you use to make this connection are acting like mistuned antennas and throwing your SWR off.
i would mount the antenna about a foot back on the bed rail.
it'll work great there.
of course, the best would be a ball mount right in the center of the roof, but...
hope this helps,
matt
anyone wanting a "clean signal", just look to the left and build one of these!!!
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