Chris, LF,
Am 14.12.2010 17:27, schrieb Chris:
HiStefan,
Yes, but 600m is VERY long! The wire
even laying on the ground I would expect to radiate quite well at 137
with that length! And how many watts?? ERP??
I am sure 8970 would do well through
the ground at the sort of powers being spoken about. Probably
ideal for submarines, as Roger says!
Vy 73, Chris, G4AYT.
Well, my earth antenna is grounded at the ends and TX power was about
250 W. The mode was DFCW-600. The receiver was at Michael Oexner using
a PA0RDT design. ERP? No idea, probably some few uW. Its not so easy to
calculate the losses.
Yes, on 137 kHz the wire length comes close to lambda/4 and above so it
acts not just like a pure earth antenna but rather as a combination of
this and a very loss dipole. On 137, my power was 100 W at this test.
The antenna was built to do local tests but seems to work suitable on
137. So it is a fixed antenna, my only fixed one. And it is a very
quiet location. This makes it interesting to use it as a RX antenna
too!...
73, Stefan
-----
Original Message -----
Sent:
Tuesday, December 14, 2010 2:49 PM
Subject:
Re: LF: Earth Electrodes
Hi Chris,
But how do you explain that i have crossed 49.6 km with a 600m spaced
earth electrode antenna on 8970 Hz? It was rather summer time than
winther (regarding QRN)! With the same antenna, my 137 kHz signal was
seen 20 dB above noise near Paris in DFCW-3!?????
73, Stefan
Am 14.12.2010 15:15, schrieb Chris:
Hi Mal,
Yes, that is what I had
concluded years ago. No harm in trying though!
Further to your previous e-mail
to LF, looks to me like beacons are now becoming the norm on 136/7kHz
band and below. I have no problem with that personally, indeed, I think
it preferable to a QSO taking forever! I woud like to see full idents
though, no matter how slow.
Vy 73,
Chris, G4AYT.
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