Hello Stefan! Thanks for your positive assessment of my new VLF set on the Apollo grabber. As you know, I changed my VLF receiver during the holidays. This one is the "second generation" of my grabber :-)
GL and 73!
Lubos, OK2BVG
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Date: Sun, 15 Dec 2013 19:47:32 +0100 From: [email protected]To: [email protected]; [email protected]Subject: Re: LF: A short VLF experiment at DK7FC
PS: The signal is on air without interruptions since 18:17 UTC. I will
run it until about 22 UTC.
Am 15.12.2013 19:46, schrieb Stefan Schäfer:
Hi Bob, VLF,
Am 15.12.2013 18:50, schrieb Bob Raide:
Stefan;
I know your busy but are you using your house ant [30 meter vertical]
for such results on8.9 kHz?? Your already DXing like with the kite
ant!!!
Yes, it is the 30m INV-L. I am about 20 dB weaker compared to the 300m
vertical experiments in 2010.
Thanks to OK2BVG for the DFCW-600 screenshot! Lubos, your grabber is
certainly the best one, together with Paul's!
I think i found the major problem which caused the instability of my
transmit signal. The active VLF antenna was connected to the RX, which
overloaded the input. Somehow the 10 kHz reference signal which is
injected by a 100pF C into the signal was swamped by the rubbish coming
from the overloaded RX. Thus i lost the track to my ref signal and the
sample rate detector didn't work properly. Now since the antenna is
disconnected (my signal is still visible, due to crosstalk) and the ref
signal has a nice S/N. Obviously the transmit signal is stable now. I
will run it for another few hours, again on 8970.00500 Hz. The last
experiment is a long time ago and i just forget about that problem.
The next experiment will be soon and i'm doing a few improvements in
the next days.
73, Stefan/DK7FC
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