Return-Path: Received: (qmail 13710 invoked from network); 14 Aug 1999 07:36:19 +0100 Received: from magnus.plus.net.uk (HELO magnus.force9.net) (195.166.128.27) by guiness.force9.net with SMTP; 14 Aug 1999 07:36:19 +0100 Received: (qmail 21457 invoked from network); 13 Aug 1999 20:00:04 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by magnus.plus.net.uk with SMTP; 13 Aug 1999 20:00:04 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 11FN1r-0005Yv-00 for rsgb_lf_group-outgoing@blacksheep.org; Fri, 13 Aug 1999 20:30:15 +0100 Received: from mta2-gui.server.ntli.net ([194.168.54.143] helo=mta2-svc.virgin.net) by post.thorcom.com with esmtp (Exim 3.02 #1) id 11FN1q-0005Yq-00 for rsgb_lf_group@blacksheep.org; Fri, 13 Aug 1999 20:30:14 +0100 Received: from default ([212.250.67.98]) by mta2-svc.virgin.net (InterMail v4.01.01.02 201-229-111-106) with SMTP id <19990813192915.DMC29980.mta2-svc@default> for ; Fri, 13 Aug 1999 20:29:15 +0100 Message-ID: <001d01bee5c2$4865cd80$6243fad4@default> From: "peter cleall" To: rsgb_lf_group@blacksheep.org Subject: LF: eclipse report Date: Fri, 13 Aug 1999 20:26:35 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.5 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org Sender: Thanks to everyone who commented on "Is anyone planning any propagation experiments on136kHz or there abouts during the eclipse next week". After your comments I decided to study it, visually and by radio techniques at home (ON5OO software). Thanks Rik for the detail on the ON5OO software. Its working out very well. I used the software to record the strength of the German station on 138 kHz during the eclipse. Location Yeovil , Somerset , England 50deg 56.5 mins North and 2deg 39mins West I am using a 54 turn 38cm diam. square loop with 0.5cm spaced turns and feeding into a lowe 225 Rx set to SSB and 2200 hz filter. This receiver has a very good AGC system which cannot be switched off. For 2days before the event I experimented to find the linear section of the AGC before the signal hit the noise floor. I needed 30dB's switched in between antenna and Rx tto acheive reasonable results. On the 10th I took a recording which shows an 8dB increase during the evening over the daytime figure with some qsb nulls. Recording was stopped at appox 2130 GMT. After the recording I left the RX on all night for stability but switched off the computer. In the morning to my horror no signal from Rx on138kHz. Eventually I retuned to another station to prove Rx working. Some time later 138 kHz signal returned, but seemed to be at least 20dB down on my previous measurements. Recalibrated the sound card and the software. I was concerned about the station level would be switched during the measurements. So the eclipse data file had a calibration switching in and out of -/+ 10dB at both the start and finish of the recording. Eclipse results 0951 GMT 138 kHz increase in level starts 1002 GMT signal variable average about 3dB up, peaking 6dB up 1025 GMT signal variable average about 3dB up, isolated peak 9dB up 1033 GMT signal returns to the pre eclipse level The follow up must be to find time to build a RX with no agc. Regards Peter G8AFN