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Re: LF: A short VLF experiment at DK7FC

To: [email protected], Paul <[email protected]>
Subject: Re: LF: A short VLF experiment at DK7FC
From: Stefan Schäfer <[email protected]>
Date: Sun, 15 Dec 2013 19:47:32 +0100
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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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