Some additional comments and observations after many years operating mobile
with the trailing wire antenna for top band (and other bands) in vehicles:
The Trailing Wire i use is actually an inverted L. When using less (horizontal)
wire it provides stronger DX Sigs. In the other extreme (longer horizontal
wire) it provides stronger "Local sigs". Actually i use this characteristic to
"trim" the antenna for the particular trip (DEP and ARR QTR, etc).
In the pictures showed at www.py2cw.net the wire is not showed and is attached
in the Whip Tip with lenghts ranging from 10 ft to 40 ft or so.
The lenght normally defined as a function of Trip QTR an estimated traffic.
Typically the cars behind (watched by a camera) doesn't present a problem.
I Had several DX 599 or even 59+ in topband. (The key over my right leg and
using a T17 converted (to dynamic) mike (no boom mike/vox).
I never became without comm. from 20m to Top using this antenna. Even in short
tunnels (1,000 ft) The sigs "scape" allowing continuing QSO. And even at pre
dawn hours in winter i always stayed at least receiving some station. And if
receiving, always able to be listened.
With the RV parked (gas gen On) and erected (vertical) antenna or inv L, 120
ft total lenght, the STN performance is superb.
An aspect i observed in the station wagon: When placing the antenna in the rear
it showed better Sigs to the front. (better "directional ground" from the
vehicle body).
The parts of the antenna and setup came from my first Guru Rolf (PY1RO) and War
Surplus parts from here and US.
Some parts from the equipment listed in http://www.qrz.com/db/py2cw and other
aircraft radios were used like RF ammeters, roller coils, variometer and big
relays.
The first operations were conducted in a fiberglass body jeep presenting a lot
of EMI/EMC issues. Finally in the RV i was able to solve most issues achieving
a good degree of compatibility between the XCVR and the laptops, Smartphones,
etc. thanks to the aluminun body of the D18 Winnebago
Finally, some safety issues: You drive slower naturally when in QSO. As a SWL
(most of time) you adjust the speed as a function of what you receive.
I faced some emergency situations (operating phone) without any problem from
the use of the ham gear. Very different situation comparing to cell phone use
issues.
Finally the mobile operation gives you an extra adrenaline from the interaction
with the other operator making (a paradox?) a safer operation of the vehicle.
Here in Brazil the Hwy Patrol "appreciates" a well maintained and equipped rare
old RV and i never had any problem with the "non conventional setup"
In over 3,000 hrs of ops. I operated 2,000 hrs "solo" and the other 1,000 with
my family (6 pob) or less "pax". TopBand background noise acting like "music".
Allowing to keep alive, like Stew (W1BB) comments on the wireless magic, the
passion for LF Comm in aviation, back in 1970 hearing Clipper Connies, DC7's,
etc.
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160 meters is a serious band, it should be treated with respect. - TF4M
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