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LF: DK7FC 137 kHz kite activity, 8. Jan.

To: [email protected]
Subject: LF: DK7FC 137 kHz kite activity, 8. Jan.
From: Stefan Schäfer <[email protected]>
Date: Fri, 07 Jan 2011 21:37:02 +0100
Cc: Marcelo - LW2ETU <[email protected]>, Alejandro D Alvarez LU8YD <[email protected]>, Yas Aonuma <[email protected]>, Bernd Grupe <[email protected]>, Ed Lesnichy <[email protected]>
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Daer LF group,

Due to the WX forecast i decided to start my activity tomorrow. It will be just on LF, no VLF activity this time. Perhaps the wind is too strong so i can only use the 100m kite with its 500 kp strong braid. The 300m kite has a 280 kp braid which might be to weak but maybe i'm  crazy enough to use it anyway. The 300m kite is allowed to be used only in daylight. So, in the night i have to go down to 100m anyway.

Apart from doing QSOs (hopefully) my goals are reaching the 4X1RF grabber in DFCW-3 and the JA7NI grabber in DFCW-60 or 90. Furthermore i remember an almost-QSO with Ed / RU6LA. Would be nice if this could be completed. I'll start in the afternoon, maybe 11 UTC, without to much stress. But i plan to stay long, so hopefully a contact to USA and maybe even Argentinia could be possible? Maybe even a trace at VE7TIL? LF-Dreaming!!!
BTW i am interested in local QSOs as well, not only DX is of interest!!

Since my LF converter isn't finished i have to use the DDS VFO for LF which is slightly drifting in a QRSS-60 window but i'll be in contact with DF6NM who can tell me the drift and offset ;-)

If all works well, my CW QRG will be 136.8 kHz, DFCW-3 137.7 kHz and DFCW-60/90 136.177 kHz(+- 3 Hz). My receivers are the 706, the K2 (with a GW4ALG 30m-converter) and the new /p RX that is under test... During transmitting DFCW-3 i will receive in DFCW-3 and 10.

My /p RX is still not optimised but at least i got a QSO with RA3YO in DFCW3/8 last year and a CW contact to M0BMU and G3KEV. I'll have my CW key there and hope for some nice contacts!

Any reports are much appreciated! :-)

Best 73, Stefan/DK7FC

Am 06.01.2011 22:33, schrieb James Moritz:
Dear Stefan, LF Group,

_Questions:_ Is my calculation reasonably useful? Would YOU add that
coil in a height of 100m above GND?

I have found with NEC simulations that they give you a reasonable idea of the impedance, but not a precise value. Especially for the resistance, where there are many unknowns - NEC really only sets a lower limit.

On the basis of the calculations, I would first try without the coil, then if results are as expected, I would try it with the coil. Otherwise there are too many variables to make sense of the experiment - if the coil goes up and the impedance is totally different from the calculation, is it because of the coil, the antenna, or the calculation?

I tend to let it be since the improvement isn't that much and the effort
is high. Furthermore the coil losses could be higher since i have to use
a thin wire to keep the weight small...

Yes - the 136k coils I have made with Q > 300 have been rather big, either with RF Litz wire or thick solid wire.

Hope to see some signals at the weekend,

Cheers, Jim Moritz
73 de M0BMU

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