I had reported earlier that my antenna current varies considerably for
reasons that I don't understand.
Last week, during a session of 73kHz T/A tests the weather was very cold and
dry with a moderate north east wind. During that period the antenna current
varied in a cyclic manner over a 24hour period from 3.9amps to 5amps!.
During the periods of high current the power supply current meter indicated
that the transmitter was using more power.
The weather in the last few days has been very wet and the lawn is
saturated. The maximum antenna current is 3 amps and that is after I have
adjusted to matching transformer to try and compensate for chang in losses.
Furthermore the current variation over the 24 hour period is not apparent.
I am located about 400m from the beach. The ground comprises 3m of heavy
clay over shingle.
The periods of high current appear to coincide with high tides.
Ground effects come in the black art category.
Regards,
Peter, G3LDO
e-mail <[email protected]>
Web <http://web.ukonline.co.uk/g3ldo>
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