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Re: LF: testing VLF grabber

To: [email protected]
Subject: Re: LF: testing VLF grabber
From: DK7FC <[email protected]>
Date: Mon, 02 May 2016 22:40:05 +0200
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Hi Max,

That's very nice, i see you know what you do.
Maybe, if you have a GPS module, you want to use pps + NMEA which is the best way to go. Search for NMEA and DL4YHF to find one of his websites describing how it is done and how the signals are combined and fed to the right channel.

Also i can recommend to add a second window to the grabber page (2nd instance) showing 'wideband', 0...24 kHz. So everyone can see if there is QRN or QRM or something wrong or an idea of the frequency response of your system and so on. It has been very helpful on many grabbers, a good overview. Maybe you a scroll rate of 1 min /pixel so everyone can watch a few hours.

After the band filter (BW 3 kHz, 1 kHz slope) you should add the noise blanker (between L4 and L5).

Your idea for a remote operated VLF station is soo nice! If there is anything i can help, don't hesitate to ask! maybe some more stations will follow, you never know who's reading. What will be the locator?

OK about both transmitting stations. Italian pioneers! What is the distance between them and you?

73, Stefan

PS: Today i have installed a single turn loop with transformer into the tree. It is now pointing to N-S again. Also my 200s symbol, 5 ch transmission is finished, so i'm monitoring again, looking into your direction.

Am 02.05.2016 18:17, schrieb Max IK0VVE:
Hi Stefan,
thanks for suggestions.

Tonight I'll suspend the grabber session to implement the 1pps GPS.
This was just a testing to see if I've problem with web upload, pc, etc... At the moment I'm using an old notebook that gives me the possibility to run a couple of SL sessions without wasting much energy. 
Ok for filtering the reception, this will improve for sure the signal quality.
Unfortunately, also living in a small rural suburb, I've a lot of noise for some years now "thanks" to new neighbor (LED lights), so I'm looking to install all system in a quieter place that can be easily approachable by a 5 ghz LAN, may be I could get ideas from your remote station, HI.

I know that IW4DXW Riccardo and IK7SLZ Domenico are warming up for VLF transmission. Rick transmitted for a while yesterday night but some capacitors problem impede a good system performance, so We are looking for new C's. I'm in the center between the two OM so could be a good place for RX test.
Not so many Italian HAM in VLF and LF now.

Thanks for now!

73, Max IK0VVE

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