DK8KW wrote:
I have found Dick's (PA0SE) field strength measurements of last weekend
very interesting. I have used Dick's observations, "normalized2 them to
dBu (0 dBu=0.775 V at 75 Ohm, so simply substract 10 dB from a dBm(50) and
you have got dBu(75)) and calculated the distances according to Dick's
QTH-Locator. A combined grpah shows both our observations in one single
plot.
http://www.qru.de/signals.html
This is a fascinating graph from which all sorts of things can be
deduced.
One interesting thing is the "estimated 1W ERP line". I would have
expected several stations to be very near (dare I say 'over') that line
but most are a few dB below it. Doing a calculation on my own dot
on Geri's graph (from Dick's measurement) suggests that my ERP is
6dB less than I calculate from the current and effective height.
So, is there something wrong with the 1W ERP line or with our ERP
calculations, or with the signal measurements? My money is on the
1W line being too high, but perhaps Geri and others with bigger
brains than me can come up with the answer.
Mike, G3XDV (IO91VT)
http://www.dennison.demon.co.uk/activity.htm
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