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From: <jrusgrove@comcast.net>
To: <rsgb_lf_group@blacksheep.org>
References: <001c01cab575$6bbb0460$0401a8c0@xphd97xgq27nyf> <20100225094846.EA85531E702@smtps01.kuleuven.be> <38A51B74B884D74083D7950AD0DD85E82A1B19@File-Server-HST.hst.e-technik.tu-darmstadt.de> <38A51B74B884D74083D7950AD0DD85E82A1B1B@File-Server-HST.hst.e-technik.tu-darmstadt.de> <001d01cab617$43e9f6b0$8d01a8c0@JAYDELL> <38A51B74B884D74083D7950AD0DD85E82A1B1C@File-Server-HST.hst.e-technik.tu-darmstadt.de>
Date: Thu, 25 Feb 2010 11:24:12 -0500
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Subject: LF: Re: AW: Re: VLF test signals?
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Stephan

This latest setup was put together for the SAQ test in December. I've=
 used various loop=20
antenna/receiver setups in the past and have had reasonable reception=
 of SAQ however no reception of=20
Alpha. This was the first time for the e probe / Perseus setup and it=
 worked very well...after the e=20
probe was put on battery power and transformer decoupled. Most of the=
 time there were no 60 Hz=20
products in the frequency range of interest (10 kHz - 80 kHz) and the=
 noise floor was very clean=20
sounding. No filtering was used between the e probe and Perseus.

There appeared to be a noticeable quiet spot in the waterfall between=
 ~ 8 and 9 kHz. I didn't=20
investigate if this was an anomoly in the system or if there happens=
 to be a quiet spot at that=20
frequency. As time permits I'll look into that further.

Jay

----- Original Message -----=20
From: "Stefan Sch=E4fer" <schaefer@hst.tu-darmstadt.de>
To: <rsgb_lf_group@blacksheep.org>
Sent: Thursday, February 25, 2010 10:39 AM
Subject: LF: AW: Re: VLF test signals?


Tnx Jay, Uwe, Jean-Louis, group,

Jay, that sounds to be a good RX concept. You do not have a band pass=
 filter in the preamp? What=20
about the 50Hz or 60Hz ;-) lines and the levels they generate at your=
 RX imput? No problem? Well=20
decoupled by the transformer? Sounds easy and at once to be built...

On that VLF SDR, the russian transmitter at 11,904kHz is really weak=
 to copy :-(

73, Stefan

________________________________

Von: owner-rsgb_lf_group@blacksheep.org im Auftrag von jrusgrove@comca=
st.net
Gesendet: Do 25.02.2010 13:37
An: rsgb_lf_group@blacksheep.org
Betreff: LF: Re: VLF test signals?



Stephan

>Which commercial VLF transmitters can actually be received in the 10k=
Hz range?

The Alpha stations on 11.9, 12.7 and 14.9 kHz are visible (cw speed wa=
terfall) and audible here a
good percentage of the time. Receiving setup is 1 meter e probe (J310=
 version of the Amrad e probe,
battery powered and transformer decoupled) to a Perseus SDR receiver.

Jay W1VD  WD2XNS  WE2XGR/2




----- Original Message -----
From: "Stefan Sch=E4fer" <schaefer@hst.tu-darmstadt.de>
To: <rsgb_lf_group@blacksheep.org>
Sent: Thursday, February 25, 2010 6:58 AM
Subject: LF: VLF test signals?


Which commercial VLF transmitters can actually be received in the 10kH=
z range? There is much listed
in the web but in times where these transmitters are shut down all thi=
s may be already old stuff.
Who is receiving in this frequency region and can tell us a frequency=
 and the SNR he is achieving?
There are so many OMs who watch the VLF sector and have nothing done=
 with LF and this group. Perhaps
it it an idea to activate/motivate them for some tests, to increase th=
e RXers density.
Maybe it is good to compare some RX rprts in that region. But i will=
 rather be active at the
transmitters front now ;-)

Stefan/DK7FC