Re: LF: Re: Re: VLF SIGS

[Roger Lapthorn <rogerlapthorn@gmail.com>]

Hi Mal,

Excellent news that you're taking steps in the 8.97kHz direction. Your involvement will be much appreciated by many and there are lots of DX records for you to set. It would give me the greatest of pleasure to decode/see/hear a signal from you.

The best chance of a signal that you might copy will be when Stefan DK7FC tests with his QRO and kite antenna next, although I believe the background noise is much higher in summertime. To copy him we will all need decent DSP based PC receivers with accurate frequency calibration and narrow effective bandwidths. As you know, Paul Nicholson copied him in Yorkshire some weeks back. My own transmissions are unlikely to be copied more than a few kilometers away. 

BTW, the main VLF military/commercial transmitters are strong here on a most basic VLF receiver and antenna. I've not  tried to listen for the Alpha beacons recently although I could copy them using my upconverter the last time I tried some weeks ago. 

73s and I wish you the best of success

Roger G3XBM

On 29 May 2010 23:43, mal hamilton <g3kevmal@talktalk.net> wrote:

Jim
The frequencies I quoted have a 750 hz offset that is why I said not
calibrated, just a rough reception guide around the frequency area of
interest.
The signals are all very loud with me. I can accurately calibrate when
necessary.
Not sure if it is a good idea to connect my antennas directly to the
soundcard, maybe via an attenuator for front end control. I also have a W &
G 220 hz - 20 khz RX which is very sensitive but wideband and would be a
better approach if I feed this into the sound card. I have a number of
options available here I just need a beacon on 9 kcs
de mal/g3kev

----- Original Message -----
From: "James Moritz" <james.moritz@btopenworld.com>
To: <rsgb_lf_group@blacksheep.org>
Sent: Saturday, May 29, 2010 8:35 PM
Subject: LF: Re: VLF SIGS


> Dear Mal, LF Group,
>
> Everyone can receive those signals in the UK, even with fairly poor
> receiving conditions (actually copying the traffic would be another
matter -
> I wouldn't go there ;-)). Most are quite strong, and in a different octave
> of the spectrum from amateur activity, so not really a good receive
> performance check - rather like using BBC R4 on 198kHz as a test for
136kHz
> reception performance. But the frequencies you list are a long way out, a
> few hundred hertz low. There is spectrum display at
> http://abelian.org/vlf/spectrum.shtml with station IDs and accurate
> frequency calibration. Bear in mind that you do need to be able to set the
> RX frequency within a hertz or less, and have much less drift than that,
for
> the kind of DX tests that have been done recently. Better in that case to
> dispense with the converter and RX, and just feed the signals direct into
a
> PC sound card - frequency errors will be much smaller, and if you are
using
> a reasonably large antenna, you probably won't even need a preamp.
>
> Cheers, Jim Moritz
> 73 de M0BMU
>
>
> ----- Original Message -----
> From: "mal hamilton" <g3kevmal@talktalk.net>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Saturday, May 29, 2010 7:31 PM
> Subject: LF: Re: VLF SIGS
>
>
> Does anyone else copy these signals? If not forget about VLF.
> g3kev
>
>   ----- Original Message -----
>   From: mal hamilton
>   To: rsgb
>   Sent: Saturday, May 29, 2010 5:15 PM
>   Subject: LF: VLF SIGS
>
>
>   Not calibrated
>   16.2, 18.1, 19.4, 20.1, 20.7, 21.8, 23.1, 23.8 Khz
>   All the above freqs active rtty type sigs and strong.
>   nil hrd below 16.2 Khz at present
>   No alpha sigs hrd today
>
>   mal/g3kev
>
>
>
>

-- 
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm
G3XBM    GQRP 1678      ISWL G11088