Let a radio engineer tell you the truth. For the proper results on phased
antennas the exact distance between antennas must be 1/4 wavelength at the
frequency used. 11 meters is approximately 108 inches or 9 feet. I don't
believe any pickup is 9 feet wide but a simi tractor could be. The only example
of properly phased whips I ever saw on a pickup was one on the cab roof and the
other at the rear of the camper topper. That was 9 feet. Also the phasing
harness used with most antennas feeds the antennas in phase so that the
radiation pattern looks like a fat figure 8 with the major lobes to the front
and rear. If the antennas are closer than 9 feet together you will still get
the figure 8 effect but there will be more radiation to the sides. So don't let
people make you think twin whips don't improve your signal to the front and rear
if they are not 9 feet apart. You will get some benefit if they are closer.
Jim in Waco, 99 R/T Ham call WB5OXQ. BS degree in electronic engineering.
Josh Stolarz wrote:
> When I had my Ferd F150 I had dual fiberglass whips mounted on the inside of
> the bed behind the cab. I got lauged at by the serious CB people because the
> whips were to close, they said they need to be mounted on the side mirror
> brackets for a dual whip setup to work. Otherwise there to close, and there
> is a technical reason behind this, just not sure of it now, was a few years
> ago. The side mirror brackets on the DAK are probaly equal to the inside
> width of the bed of my old F150, so putting it on the mirrors of the DAK
> will probaly not work. I used a single 8 FT. fiberglass whip with a peaked
> and tweaked CB, and it worked great...
>
> Josh
>
> 00 4x4, 4.7, CC, SLT+
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