Thread: Service Help
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Old June 15th 05, 08:21 PM
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" wrote in message
oups.com...
Thank you again for your replies.

I agree with your assessment that much of our (company's) internal
(operational) systems may be considered "broken" by virtue of current
circumstance. Unfortunately (or perhaps fortunately depending on ones
point of view), I am not in a position to have any real effect in
matters I am not paid to have an opinion on.

However, regarding the communications amongst the 40 or so busses I can
have a positive effect on, there may be some positive contributions I
can make. I have recently learned that our mechanic has been the one to
install the radios, coax, and antennas all along.

The way the (broken) system apparently works:

Barn gets new bus in.
Manager asks for permission to buy new radio for new bus.
Uppon approval, manager orders new radio system (radio, coax, antenna,
hardware, etc.), from local company.
Mechanic installs new radio into new bus.
Everyone hopes for the best.

In the course of conversation with our mechanic this morning on the
matter, I learned that he has mounted a number of the antennas on a
part of the bus that is fiberglass. I tried to explain a bit about
ground-plane to him and the need for the antennas to be mounted on a
metal part of the bus. I' am having him take one of the "worst"
communicating busses and move the antenna to a metal part of the bus. I
am also having him go through all the contacts and connections and
cleaning them. I'll post what was done and what the results have been.

Thanks again for your help!
Mike


Mike -

VERY USEFUL INFORMATION.

Yes, fiberglass is worthless for the required ground plane of a 1/4 wave UHF
antenna - and requires additional materials.
PCTEL based in the Chicago area is a major antenna mfg. and suppliers (e.g.
MAXRAD, Antenna Specialists).

They have 2 suitable products specifically made for fiberglass body vehicles
and antenna mounting (Page 44 of their catalog)
http://www.antenna.com/lm_cat/pdf/lmr_catalog.pdf
Ground Plane Kit Model K-67

Ground plane kit for fiberglass-bodied vehicles. Complete with instructions
and sufficient adhesive backed foil for one low-band/high-band or six UHF
ground planes (3 inches x 44 ft). Includes metal clips for circuit
continuity.

Ground Plane Disk Model K-332

Provides ground plane for fiberglass-bodied vehicles.

THIS NEEDS TO BE ADDED TO THE "BILL of MATERIALS that you are ordering from
the "local company" supplying the radio and antenna materials

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Greg, w9gb