To: rsgb_lf_group@blacksheep.org References: <000c01c61c28$c72b2180$1de8fc3e@l8p8y6> Date: Wed, 18 Jan 2006 15:35:52 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2615.200 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2615.200 Subject: LF: Re: OBS Content-Type: text/html; charset=windows-1252 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SpamFiltered: by PlusNet MXCore (v2.00) Content-transfer-encoding: 8bit

Hi Mal, thanks for that. Yes as the pattern for a loop is a "half-doughnut on edge" like a dipole you would expect some signal from a DX station. particularly as it would be arriving by "skywave", where there should be some response. I guess at Brian's distance one hop is arriving at zero elevation, and the null in a well designed loop can be quite deep. Also Argo is very sensitive, if that is the right word, it goes from just a trace to a full "O" in about 3 to 4 dB change in strength.

Ok on the differences in aerials and local noise. This is always a problem and it is why Brian and I made such an effort to calibrate the aerials we used for regular moniring and then to mainly record commercial stations with "fixed" operating conditions. Even then stations like CFH could suffer lower ERP when the aerials were, on one occasion, shrouded in ice. All comments / reports are interesting and help to add to the knowledge of events I am trying to build up. This quiet sun period is proving an interesting time contrasted with the franctic solar activity during the peak. In some ways it is easier to isolate cause and effect.

Cheers de Alan G3NYK

----- Original Message -----

From: hamilton mal

To: rsgb_lf_group@blacksheep.org

Sent: 18 January 2006 12:14

Subject: LF: OBS

Hi Alan and Co

Just for intrest. I monitored 136.9 khz last night around 2000z and observed CT1DRP, who was a good signal on my vertical antenna. I then switched to my 80m vert loop which is broadside on to Brian, and saw absolutely nothing.

This is to be expected I suppose since the loop is max East/West although I did expect to see something, even very weak.

My noise level at the time on the vertical measured 69.5 db and the signal from DRP 41.3 db indicating a signal over noise of 28.2 db.

Since I am the most northerly station active on LF from the UK and the greatest distance from DRP I thought the info might be helpful to you with your observations. Someone else might have recorded some info at the same time in EU.

One other observation. On my vertical the Rugby qrm signal is fairly consistant but with the loop it fades in and out, but again Rugby is south from me and min sig pickup, for example the display is absolutely clear of qrm then suddenly lines appear from Rughy and after a very short spell they disappear again. The angle of arrival and direction could be changing with propagation changes, or maybe my vertical is having an effect inducing the Rugby signal into my loop at times.

I suppose it is important when making propagation observations to consider antennas used for both transmitting and receiving at the various places. Since in the amateur service no two stations are using the same power and antennas it is difficult to come to a meaningful conclusion.

Good luck with your propagation data experiments.

de Mal/G3KEV