When u co-phase antennas you split the power between two antennas,
co-phasing will give you a 3db gain,
(when done correctly) 1/4~ antennas HAVE to be
placed a 1/4~ apart or else the near-fields will overlap and any gain you
hoped to produce be lost.
Don't waste your time my friend, you will get better results with 1 antenna
mounted in the center of the roof!
Go with a Wilson Lil Wil.
Co-phased antennas look cool but don't work and will
actually decrease the performance unless set-up correctly.
a 1/4~ is approximately 9ft. or 102".
--
Mad Dog

"PES949" wrote in message
...
I am thinking of getting a Twin Trucker for my Ford Explorer...

I would mount the antennas to the roof rack and run a ground wire since
the
racks have a rubber gasket to prevent leaks. I also want to use springs at
the
base in case I get some low branches etc.

Will the springs hinder the quality of the signal? If so, is it marginal?
Is the ground wire idea ok?

Rinning a Cobra CB.