It can be done! All I have to do now is get
the thing solid enough to operate on the move. With the setup shown "static
mobile" in the Worcestershire countryside I have worked GW4ALG in Chepstow
(102km), G4HYU in Louth (166km), G0UPU in Cheltenham and G3YMC in Bracknell. I
have also had a good report from G3KEV in Scarborough (237km).
The amber coil is a huge 23mH job which, even
with the 12ft tank-whip on top wasn't quite enough to resonate on 136kHz. I had
to add some horizontal(ish) rods just above the coil and a bit of extra
inductance in the form of my /P loading coil and variometer seen on the roof.
The portable TX was used and, with about 300W of RF I was able to get almost 1A
of aerial current with only the car body for earth. I have since used a longer
top section of 15ft and it then loads OK without the extra coils. All I have to
do now is reduce the height to 14ft overall and we're really
I'm not the only one nuts enough to try this,
G3XTZ has also operated /M using a vacuum variable C inside the car connected
to a top wire attached to his whip. So far only a few miles range but I'm sure
the system is capable of more. We must try a mobile to mobile QSO...
Interested in HF mobile
operation? More info here..