[Lowfer] Fw: 19.2 kHz - VTX4 - India

[jrusgrove at comcast.net]

 David

 Here's some further info on my reception reports of 19.2 kHz - VTX-4 - India the past couple years. 
When identifying a VLF
 station I go through the following process.

 First I determine if there are any known receiver spurious signals in the frequency range. Luckily 
I
 have only two weak ones - one each at about 10.67 kHz and one at about 22.6 kHz. They typically 
have
 a distinctive sound unlike any of the bonafide FSK or RTTY transmissions. Here's a short .mp3 of
 22.6 kHz.

http://www.w1vd.com/22dot6kHz.mp3 .

 For comparison here is an .mp3 of  19.2 kHz - VTX-4 taken a short time ago.

 http://www.w1vd.com/19dot2kHz.mp3

although weak, it has the characteristic FSK sound as with
 other VLF signals. Here is a spectrogram at the time of the recording.

http://www.w1vd.com/VTX4012614.jpg

 I also watch and listen for the signal at the same time and other times of the day to see if it's
 a regular occurance. The reception must occur at an appropriate time of day.

 Finally I look for corroboration from other receivers around the world. For this I use the World
 Wide Lightning Network (WWLN) receivers. I pick receivers from their worldwide array in
 the vicinity of the transmitting station. Here's a link to their receivers.

 http://webflash.ess.washington.edu/

scroll about half way down the page ... locations are shown
 at the left. Also, here's a handy visual link to most of the receivers. Click on them for full size 
images.

http://webflash.ess.washington.edu/spectra.html

 For 19.2 kHz - VTX-4 - India I'm particularly interested in the Singapore, Beijing and Nanjing 
spectral
 displays. They clearly show activity on that frequency as do other receiving stations further away.

 That's the ID process in use here. I rarely report a station on a first reception other than a 
short
 term Tacamo transmission as I really want to avoid sending anyone on a wild goose chase!

 Jay W1VD  WD2XNS  WE2XGR/2  WG2XRS/2



 ----- Original Message ----- 
 From: "David L. Wilson" <dwilson314 at verizon.net>
 To: "'Discussion of the Lowfer (US, European, &amp; UK) and MedFer bands'" <lowfer at mailman.qth.net>
 Sent: Saturday, January 25, 2014 7:26 PM
 Subject: Re: [Lowfer] 19.2 kHz - VTX4 - India


>I have never seen 19.2 kHz here after many tries and worry about the fact
> that it is a common data rate frequency and interference might be identified
> as it.
>
> I plan another late night.  I have heard most of the Russian beta stations
> on all their frequencies but lack the RJH63 on 25.0 and 25.1 due to USN 24.8
> and 25.2 being much strong here than that one.  Will try using the loop
> tonight instead of E-field probe.
>
> --
> David L. Wilson
>
>
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