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
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
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
I tend to let it be since the improvement isn't that much and the
is high. Furthermore the coil losses could be higher since i have to
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