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Re: Joe on VLF:

To: [email protected]
Subject: Re: Joe on VLF:
From: [email protected]
Date: Sat, 1 Apr 2017 18:27:01 -0230 (NDT)
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Hi Stefan,

Thank-you for the revisions to the config file. It was opened 2330 last night and seems to be more sensitive though that
may be caused by something else. From 0010-0025 the the aerial
current was reduced by 1/5 and the amp was switched off at 0040.
The spectrogram shows the shows all the fun and games.  The freq.
is a a bit high -- evidently the procedure that Markus
guided me through is not being applied by the config file.

The stability is better than can be measured against WWV (10 MHz) so perhaps I will try 60 kHz (WWVB).
Also last night, Spectrum Lab was reading an old Garmin Etrex
GPS via rs232/usb.  DL4YHF has made provisions for doing this via the
sound card.  Amazing!

My aerial is in bits and pieces, tangled in the treetops and
the halyards are frozen to the pulleys so we need a warm day
before having a go at the far field!

Which hill were you thinking of for a VLF grabber?

Cheers
Joe


On Fri, 31 Mar 2017, DK7FC wrote:

Hi Joe,

I changed the subject ;-)
The settings were not bad, just the delay/echo line was enabled, which is not necessary. In attachment is another usr file with some more complex settings optimised for individual noise blanking on 8270 / 11904 Hz. Maybe it works a bit better. Just try and compare.

If everything is configured fine then you should reach the far field easily. Maybe you can make a recording (wav file), 1 minute would be fine. Are you using the latest SL version? How stable is your signal? Would be interesting to see a spectrogram of your own signal...

A VLF grabber on the historic hill, what about that? :-)

73, Stefan


Am 31.03.2017 21:07, schrieb [email protected]:
Hi Stefan,

It seems the delay is a blacksheep thing. Fortunately it doesn't happen often.

Your reception of my VLF will be a big day indeed. At the moment, the
sigs appear to be constrained to the near zone. The best DX was 5.2 km
using spectrum lab but this is now only about 1 km.  The signals are
quite audible with a crude RX at 1.5 km. Evidently, this OM is not
competent in SL operation.  Perhaps this can be verified by looking
at the attached configuration file which was modified (bungled?) from
Wolf's 8270Hz_QRSS_4mHz.usr.  The level range in the output file is -145
to -81 dB and the spectrogram shows a peak at 8277.16 Hz.

Thanks for your offer to help!

73 and congrats to you and Paul again.
Joe VO1NA


On Thu, 30 Mar 2017, DK7FC wrote:

Hi Joe,

Your recent emails came through now, with some delay since the 27th.

Thanks for your kind words regarding ULF. We are waiting for your signal on VLF. A true RX challenge for me!

If you need help with special SpecLab configs, we can arrange a Teamviewer remote access. I'm doing this daily now on various PC in various countries :-)

73, Stefan

Am 29.03.2017 00:10, schrieb [email protected]:
attempt 4




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