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Date: Sat, 30 Jun 2007 19:40:57 +0100
From: John GM4SLV <gm4slv@sighthound.demon.co.uk>
To: "hamilton mal" <g3kev.ham@virgin.net>, <rsgb_lf_group@blacksheep.org>
Message-ID: <20070630194057.14c38f83@lurcher.twatt.local>
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	<000801c7bb3c$cf904940$2bccfc3e@g3kev>
Organization: The Gammy Bird
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Subject: Re: LF: Re: Getting QRV on 500kHz from Shetland?
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On Sat, 30 Jun 2007 17:33:11 -0000
"hamilton mal" <g3kev.ham@virgin.net> wrote:

> Have u given up john. Lots of msgs giving u some advice about 500,
> but you seem to have evaporated, no response.
> 73 de Mal/G3KEV
> 


Hi Mal,

Far from evaporting....

I listenend in both a 1m dia tuned loop and my 30m GP to ~500kHz last
night, both to our band and to 518kHz NAVTEX. Heard no amateur traffic,
but lots of NAVTEX. I left the decoder running over night and the
signals stopped decoding at 0600z once it was too light for any
propagation.

I spent the day today putting up a "temporary" antenna for RX purposes. 

It started out as a simple vertical, on an 8m fishing pole with no
radials. When I came into the shack I was amazed to hear you calling
CQ, but only RST229 (I misread you call as G3KEQ due to the extremely
low signal strength). 

I was too busy running in & out of the house and raising/lowering the
antenna to post on the reflector too!

Next I added 4 shortish (~10m each) radials lying along the ground. I
will try to get an couple of rods banged in when I find something
appropriate to use...

I then wound a loading inductor on an empty wine bottle (the only
decent insulator I had of an appreciable diameter) to try to remove some
of the capacity. 

My latest addition is 10m of top loading wire, making it an inverted L.

The loading inductor must be approx 400uH or so according to my
calculations and it makes a measurable difference on receive -
comparing the strength of the "NL" NDB on 404kHz with/without the
loading L shows an S point or so improvement with the L in place.

I've just been RXing NAVTEX from OST and LGD at 1800 and 1810 UTC on
518kHz and at now 1820 I'm not getting (albeit errored) NAVTEX from GPK.

I've been listening, and watching on SpectrumLab, to the whole 4kHz
chunk between 501 and 505 most of the day (when not involved with
working on the antenna or being sent to do the shopping by the XYL) and
apart from hearing you a couple of times very weakly I've heard nothing
else. I did exchange message with Colin 'VTT on the reflector to say
I was listening for him calling CQ, and I see from other postings that
there's been quite a bit of activity today, but none of it audible up
here.

This antenna is just a lashup for the weekend to get a feel for things.
I'm not even going to bother waterproofing any of the connections. Once
I'm happy that something reasonably simple can hear things then it'll
be time to invest time & effort in something more substantial (XYL needs
careful treatment when new antennas are being installed - hi!)

So - I've at least heard one station, in daylight, so perhaps it can be
made to work.

Thanks for the encouragement, sorry I'm not quite as speedy at getting
QRV as you were hoping...there's only so much time in a day!

Cheers,

John GM4SLV


-- 
G-GRP-Club 2377, QRP-ARCI 12384, SKCC 3214
Member : RSGB, ARRL
Shetland Islands (EU-012) IP90GG 
Lerwick Radio Club : http://www.gm3zet.org