Return-Path: Received: (qmail 21955 invoked from network); 23 Mar 1999 14:52:52 -0000 Received: from magnus.plus.net.uk (HELO magnus.force9.net) (195.166.128.27) by medusa.plus.net.uk with SMTP; 23 Mar 1999 14:52:52 -0000 Received: (qmail 7953 invoked from network); 23 Mar 1999 14:55:50 -0000 Received: from post.thorcom.com (194.75.130.70) by magnus.plus.net.uk with SMTP; 23 Mar 1999 14:55:50 -0000 Received: from troy.blacksheep.org ([194.75.183.50] ident=root) by post.thorcom.com with esmtp (Exim 2.04 #3) id 10PSXB-0007Bx-00; Tue, 23 Mar 1999 14:52:01 +0000 Received: (from root@localhost) by troy.blacksheep.org (8.6.12/8.6.12) id OAA29540 for rsgb_lf_group-outgoing; Tue, 23 Mar 1999 14:47:36 GMT Received: from post.thorcom.com (root@post.unica.co.uk [194.75.183.70]) by troy.blacksheep.org (8.6.12/8.6.12) with ESMTP id OAA29497 for ; Tue, 23 Mar 1999 14:39:32 GMT Received: from kang.tinet.ie ([159.134.237.28]) by post.thorcom.com with esmtp (Exim 2.04 #3) id 10PSOI-00060O-00 for rsgb_lf_group@blacksheep.org; Tue, 23 Mar 1999 14:42:50 +0000 Received: from p137.lifford1.tinet.ie ([159.134.235.137] helo=beachwood.tinet.ie) by kang.tinet.ie with smtp (Exim 2.05 #23) id 10PSKZ-0003i1-00 for rsgb_lf_group@blacksheep.org; Tue, 23 Mar 1999 14:38:59 +0000 From: "finbar o'connor" To: rsgb_lf_group@blacksheep.org Subject: LF: Fw: EI.SUN.RPT. Date: Tue, 23 Mar 1999 14:41:21 -0000 Message-ID: <01be753b$383b8e60$89eb869f@beachwood.tinet.ie> MIME-Version: 1.0 Content-Type: text/html; charset=windows-1252 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.71.1712.3 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org Content-transfer-encoding: 8bit
 
-----Original Message-----
From: finbar o'connor <beachwood@tinet.ie>
To: rsgb_lf_group@blacksheep.org <rsgb_lf_group@blacksheep.org>
Date: 23 March 1999 14:40
Subject: EI.SUN.RPT.

                                                                                                                                                            worked  a number of stations last Sunday night  2130 - 2340 utc on  137.1 khz    
 
  
I also had a number of msgs from those who heard the transmissions,  tks for the comments and help.
To:  Peter  DJ8WL ,  Hajo  DJ1ZB ,  Marzio  I5MXX ,  Mike  G3XDV , John  G4GVC                 
       Jaap PA3GUC  ,  Christer  SM6PXJ , Reino  OH1TN , Dave  G3YXM .
 
First  I have to say , it was very well worth the effort, taking all the bits and pieces and setting up the rig and atu  to tune the big antenna. I had wound a new coil on a plastic linen basket , using a single  turn of large heliax co-ax , soldered into a  shorted  turn,  it worked great as a variometer, but  I did not have time to  put tappings in and found it was too large, even with the variometer function to tune the large  'Tee'  to resonance. Luckily  I had brought my two other variometers with me ( they are wound on  plastic paint containers ), I got on the air  just after  2130 utc. The transmitter  used is my  own circuit ( see  LF Sourcebook for  details ) using  a pair of IRFP450  mosfet's in parallel.  Started off with  3.4 amps into the antenna but after a while that dropped to  3.1 amps. The power supply  transformer was very hot by 2345 UTC  when I packed away  the bits into the banana box.  I use a  Variac , to vary the power supply to the  ht for the  Mosfets, that way I can bring up the power in stages and make sure everything is working fine before full blast.  54 volts on Mosfets at full bore.  I use a  very wide spaced coil  to ground , which I tap up to match the transmitter ,  there  is  a trade off between, match,  output and current drawn by the P.A.
 
The receiver used  was  an  Hagenuk  rx 1002,  a fine receiver, but to be honest after  last Sunday I feel there is a definite need to properly match the receiver to  LF.  The way we have things at work is  a  development from the old days , when most of our work was on  500 khz.  We have  7  receiver's all taking their feed off the one antenna, via  a  passive  resistive pad  of  50 ohms. The band was not that clear on the receiver last Sunday,  there seemed to be an amount of cross modulation,  I even heard the 138.8 khz signal in places I would never hear it on the band. My next project is to specifically  match the receiver to the band and see what effect that has, or failing that to  run out  a seperate wire antenna to a spare support on one of the  50 m masts. 
 
The mast  supports are  50m high,  strung between them is the old 500 khz  single wire  'Tee', which is brought to resonance with  about  1900 UH.  The span is about  120 metres.
I found all the  qso's and reports really interesting and it makes it worth while setting up the station.
The comments regarding my signal fading way down  and  the weak  sigs from OH1TN ( I never heard him) shows the effects on the band  at long distance, to be honest , I was quite suprised  my signal dropped down so much.  Working into  120 km  ENE of Munich , for the first time on LF was very pleasing, as was working  Marzio I5MXX, his signal was very very weak, but readable,  so too was  G3XDV,  very weak indeed, but again, if I can  peak up my receive side I feel  I could pull in a lot more.
I wish I knew how to attach  a photo, so that you could see the set up, plus a picture of the radio station would give you all an idea of what the place is like and where the signal is coming from
My very best regards to all and thank you for all your  comments.
73's   FINBAR     EI0CF