dual cb antenna is it worth the trouble
 

will two cb antennas make a big difference my friend is going to
put two mobile antennas on his truck i told him it will more
trouble than it is worth. because to set the swr will be a pain
thanks and 73s

http://community.webtv.net/jcooper874/doc
click here
http://community.webtv.net/jcooper874/haveagreatday

http://community.webtv.net/jcooper874/doc0

jc,
Your right, they're more trouble than they're worth,
and most of the claims for them are pure myth.
'Doc

That depends on a bunch of factors you didn't mention. A 1/4 wave CB
antenna is about 11 feet long IIRC. More important, it needs a ground plane
with the same radius. Most perforce shorten the antenna using coils, at the
expense of efficiency and pattern shape, and get by without an optimum
ground plane but both transmission and reception suffer - how much depends
on the vehicle, the antenna(s) and where you mount it/them. A pair of
antenna may yield a pattern favoring the road ahead and behind depending on
seperation. That's why big rigs use them. I had a cross-bed tool box with
one 6' "Firestick" mounted in it's center that worked as well or better than
anthing else I tried.

Of course 2 meters is the better solution.


wrote in message
...
will two cb antennas make a big difference

That's what I always thought, but according to one of the links you provided
http://www.signalengineering.com/ult..._antennas.html
it's done to even out the skew in the omnidirectional pattern caused by the
asymmetric vehicle ground plane.
For the 18-wheelers with side mirror mounted antennas it might also help to
eliminate the shielding effect of the large trailer body if only one antenna
was used.

A real simple measurement would be to walk a circle around the truck with a
field strength meter and see what you've got.

But for anything else than an 18 wheeler I think it'd be a total waste. But
then again with CBers it's not just about how you sound but about how you
*look* !

John




wrote in message
...
will two cb antennas make a big difference my friend is going to
put two mobile antennas on his truck i told him it will more
trouble than it is worth. because to set the swr will be a pain
thanks and 73s

http://community.webtv.net/jcooper874/doc
click here
http://community.webtv.net/jcooper874/haveagreatday

http://community.webtv.net/jcooper874/doc0

Hi J

Many eons ago, almost more than I care to remember, I was using SIX
102 inch whips on my rig. They were actually two sets of three whips
cophased together. Using three whips in a small 3 inch triangular
pattern allowed the whips to be shortened so they would not clip the
occasional low bridge. The purpose of cophasing was obvious, it was
to get more front and rear directional along the roadway.

Whether you use a single whip on each side, twin whips or triple whips
your spacing between the two units must be far enough apart for it to
make any difference. Or, in our case, that big box behind us was like
a shield to radio signals.

FWIW, a 1/4 wave magmount sitting on top of the trailer was often more
effective in and around cities, where a 1/2 wave magmount was more
effective on the road than the cophased whips. That is, until you
crossed under a bridge and wiped them off the trailer.

Unless you can get those whips at least 8 feet apart, it's not really
worth messing with!

TTUL
Gary