VLF,
Am 15.11.2011 17:03, schrieb DENNIS EASTERLING:
[...] I also have a mini-whip, but this has
been extended for
VLF purposes. [...]
...which is good since soon there will be some activity again on 8970
Hz. If you like you can join in to the group of successful listeners on
the 33 km band.
Yesterday i carried my TX coil to the fixed antenna here. Also the PA
and variometer part of course. I do inted to use the fixed antenna.
I did some calculations about the radiation resistance and losses and
power at maximum voltage (50 kV rms on the wire) and found that the ERP
will be about 10 dB higher than expected, i.e. i could radiate
something in the range of many 100 uW up to 1 mW or theoretically up to
2 mW. We will see and measure.
Paul Nicholsen reported about a very senistive receiver in USA that
allows long time integration, i.e. not producing a spectrogram but
integrating a given TX time into a single bin, like Paul usually does.
Here on the fixed antenna i could do night transmissions. 500W TX power
key down for 24h is no problem (as long as there is no rain).
So i am optimistic and looking forward to some new work on the dreamers
band!
Also i would be interested if there is (still) some interest in VLF in
this group. For Paul, a endless straight "carrier" would be the
optimium while a radio amateur may like to have some true ID and maybe
a message to be read and displayed. What about the grabber runners and
new prepared VLF receiving stations?
Probably i will start next week but may do some spontaneous tests
before...
73, Stefan/DK7FC
PS: I would like to see other VLF transmitting stations as well. What
about G3XIZ, DF6NM, OE3GHB, OE5ODL, OK2BVG, DJ8WX? We all could leave
some common traces again in the excellent dark spectrogram backgrounds!
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