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Re: VLF: Antenna switching

To: [email protected]
Subject: Re: VLF: Antenna switching
From: [email protected]
Date: Wed, 15 Feb 2017 16:15:12 -0330 (NST)
In-reply-to: <[email protected]>
References: <[email protected]> <[email protected]>
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Thank-you for the interesting reading and congrats on your latest

There have been some very modest steps taken on this side of the
pond.  New coils were wound with 12 strands of 0.08mm insulated
copper: 2 pies 170 and 110 mH, combined 487 mH, 234 ohms DC.
The 100m wire at H=15m was just tuned and I'm happy to be QRV again
on VLF a month after the licence was renewed.


On Wed, 15 Feb 2017, DK7FC wrote:

Hi Markus,

I know!! And you are not the only one who doesn't like NMEA. I like it however :-) In my opinion, the favoured solution would be to build up a VLF RX system in a quiet location nr N├╝rnberg! :-)
73, Stefan

PS: There was a bug in the script, now solved.

Am 15.02.2017 18:45, schrieb Markus Vester:
Hmmm Stefan, if unannounced transmissions can buy me precious East-West antenna time, I guess I should revert to surprise operations as well ;-)) In my opinion, the favoured solution would be to kick out NMEA and listen on both antennas simultaneously, with only 1pps superimposed on the right channel.
Best 73,

-----Urspr├╝ngliche Mitteilung-----
Von: DK7FC <[email protected]>
An: rsgb_lf_group <[email protected]>
Verschickt: Mi, 15. Feb 2017 15:21
Betreff: VLF: Antenna switching

Hello Markus, VLF,

My antenna switch works now. I wrote a small script (just my level of
skills, while loops and so on ;-) ) that allows tto switch from the
north-south loop over to the east-west loop to a certain time and then
back to another time.
The script is now tested the first time, i switched to EW since 14 UTC
and will be back on NS at 16 UTC. You can see the difference at
So, Markus, if you want to try a short EbNaut transmission soon in the
morning, just tell me the day before, then i can switch the antenna to
you just during the start of your transmission, while i'm still
sleeping. And then back into Uwes direction, who prefers unannounced
transmissions :-)
I als removed the grounding on the relay pin of the unused antenna,
which caused a coupling between the loops. Now it all should work well...

It opens new playing fields, e.g. testing an alternative E field antenna
on the second input. That will be a better choice for the 970 Hz

73, Stefan

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