Here i agree. And here i understand "dreamers" in a positive and optimistic
way, just like children are dreamers!
We have written so many mails (including me, of course ;-) ) und could start
now just to try what is possible to reach more than 10km if not done yet.
On the LF pages of DK8KW i found a notice of a successful 2 way QSO over 10km @
<9kHz. Does anybody know about more than 10km by amateurs?
Yesterday in the night i talked more than 1 hour to Markus/DF6NM and he
persuaded me to try it with the 100m vertical in a first test. Maybe i get that
temp licence for a 300m kite vertical but the public autoritys are still
discussing if i need a special casualty insurance...
Do you, the group, think that it makes sense to try it if the next listening
station is >50km or even more away? What could be possible if this would be the
arrangement with the 100m vertical:
The wire has abt 580pF
I can get a air coil with L=85mH out of a 20kV field. DC resistance abt
150mOhm, continous current abt 30A, voltage over coil abt 30kV rms (if it
remains dry(!)), measured self resonance frequency abt 50kHz.
So, if f=8,9kHz, a parallel C of abt 3,2nF is needed (i can get some 470pF/40kV
Cs, no problem)
The voltage across my thin wire should be limited to abt 20kV rms, that means,
antenna current should not exceed 650mA.
If Rik's 1/f dependency is valid, then my ground losses will be in the region
of 250 Ohm (no houses and trees there on the hill in a radius of abt 100m;
15Ohm @ 137 kHz).
So, 100W TX power would radiate 1,4mW and thus the efficiency would be 0,0014%.
In that case, i mustn't apply more than 100W since the voltage across the wire
would be to high, so no need for a QRO PA...
If that calculation is reasonably correct, what distance could be reached with
1,4mW @ 8,9 kHz in e.g. QRSS10 and the noise level that can be expected on a
sunday morning? :-)
73 es wish gl to all those, who are trying in these days ;-)
Stefan/DK7FC
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