Eddie, Markus and group!
The long bright line was indeed caused by a local test.
Eddie: My grabber is locked to GQD and should display the QRG very
accurately! So what you see is what you get!
Ossi did some test during the past days and due the warmer temperatures
his DDS moved down to the QRG where I use to transmit. 8969.98
I didn't transmit since last Saturday and so any signal shown on ,,.98
since is not from me!
BTW: I'm experimenting with a different active antenna (DK7FC design)
and first test seem to be promising. Maybe my grabber will be more
sensitive soon!
73
OE3GHB
Gerhard
Am Mittwoch, den 16.03.2011, 00:46 +0100 schrieb Markus Vester:
> The OE3GHB grabber shows a long bright line on 8969.98 from 16:00 to
> 4:30. The sensitivity was not degraded, so perhaps only a local
> oscillator test.
> Or a nighttime carrier from OK2BVG? But it looks stronger than the
> subsequent "KKK" which Lubos sent on 8970.02 / .04 from 6:00 to 15:45.
>
> OE5ODL then shows a very bright "riser" from 6:15 to 14:15. This was
> his own transmission, also visible at DK7FC.
>
> So probably two different signals, both on 8969.98. Could it be that
> Roger's screenshot has hints of both?
>
> Best 73,
> Markus (DF6NM)
>
>
> From: Roger Lapthorn
> Sent: Tuesday, March 15, 2011 11:13 PM
> To: [email protected] ; Eddie ; [email protected]
> Subject: LF: VLF reception - easily mistaken!
>
>
> A word of caution to those of us looking for very weak signals around
> 8-9kHz.....
>
> DJ8WX was copied here overnight without any doubt and my grabber was
> clearly able to see his close-down around 0700 today. The frequency
> and the trace timing corresponded perfectly. Likewise with G3XIZ and
> DK7FC/P some weeks ago.
>
> This evening I was looking very carefully again at the Spectrum Lab
> screen from the last 24 hours in 424uHz BW and readjusting audio gain
> ranges, screen colour saturation and contrast. Out of the noise
> appeared another very very faint line, not at 8.970022 but at
> 8.96998kHz. I've attached the screen shot here (I have overlaid it
> with the time for clarity).
>
> My immediate reaction was this must be Ossi OE5ODL. Then I checked his
> grabber and saw he was not operational overnight last night! So, what
> looked like a trace on his frequency cannot be him. It must instead be
> some artefact of SL or something else.
>
> So, Mal is right (did I just say that? :-) ) that we have to be very
> careful when seeing traces at specific frequencies: it may be an
> indication of a given station, but without some modulation or turning
> on/off of the carrier a doubt remains.
>
> Sadly I don't think I did see Ossi today after all, but I shall keep
> looking.
>
> 73s
> Roger G3XBM
> --
> g3xbm-qrp.blogspot.com/
> www.g3xbm.co.uk
> www.youtube.com/user/g3xbm
> G3XBM GQRP 1678 ISWL G11088
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