Dear group,
We can be optimistic about further successes in the VLF sector i think. The
most enjoyable finding (within ham experiments)is, that the E field decay relly
seems to be rather ~ 1/sqrt(d) than ~1/d :-) That is an important difference to
137kHz, isn't it?
A little dreaming:
Does that mean that if the ERP is 3dB higher (21kV instead of the 15kV i had
yesterday), the maximum distance will be 4 times the old distance, ideally?
That would mean, with a 300m vertical +3dB QRO, the ERP is at least 13dB more,
so the distance could theoretically cover the whole world?
We are now about 3kHz below the lowest alpha station!
What about the retireds of you? For you it would be ideal and easy to check
what is possible with the earth antennas. Just buy some 100m of cable and
bury/hide it at midnight near a field or a forrest. Then, apply some power out
of a audio amp, for a first step. A QRSS mode message could be recorded to a
cheep usb-mp3-player as a mp3 file and could be transmitted, even in repeat
mode. Starting with 2x50m, then going to 2x100m and so on. Then, the dependency
of the virtual loop area could be estimated. Not expensive, no trees or towers
to climb, no high voltage, no big garden needed. You just don't have to ask for
a permission for that ;-)
Would be interesting!
73, Stefan/DK7FC
________________________________
Von: [email protected] im Auftrag von Mike.WE0H
Gesendet: Di 16.03.2010 20:44
An: [email protected]
Betreff: Re: LF: 8.97kHz antennas
Years ago it seemed difficult to radiate a good LF signal, that changed
when many guys got on the air and figured it out; same with the MF band.
This VLF band could be the same way. Get on the air and try different
antennas and equipment until you figure it out. Maybe someday the VLF
band will be busy with many stations?
Mike
WE0H
/16
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