Since the radio was so noisy this weekend, I spent time both
improving the transmitted power and getting a better idea of the real
antenna current.
I finally managed to get 1.7A into my inverted-L from my 200W Tx
to give 135mW ERP.
Several stations have commented on the strength of the key-up
'spacer' signal from my Tx (yes, I will fix it). Since my current meter
does not read at all when the key is up, it took some time for me to
come up with a measured power level of the leak-through. I found it
was 3W, which gave an antenna current of 210mA, and an ERP of
2mW. (Incidentally, when I first started on 136kHz, my current was
not much more than this and the antenna was smaller!).
Two UK stations have heard this signal and Rik, ON7YD, can just
read it on his Spectrogram screen. At 176,500km/watt is this a
record?!!! It certainly shows what can be done with an extremely
low ERP.
Mike, G3XDV (IO91VT)
http://www.dennison.demon.co.uk/activity.htm
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