Return-Path: Received: (qmail 10852 invoked from network); 23 Jul 1999 10:30:28 +0100 Received: from magnus.plus.net.uk (HELO magnus.force9.net) (195.166.128.27) by guiness.force9.net with SMTP; 23 Jul 1999 10:30:28 +0100 Received: (qmail 16111 invoked from network); 23 Jul 1999 09:32:50 -0000 Content-Transfer-Encoding: 8bit Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by magnus.plus.net.uk with SMTP; 23 Jul 1999 09:32:50 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 117bVs-0003X9-00 for rsgb_lf_group-outgoing@blacksheep.org; Fri, 23 Jul 1999 10:21:08 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from gatek.vs.dasa.de ([195.243.118.226] helo=gatekeeper.vs.dasa.de) by post.thorcom.com with esmtp (Exim 3.02 #1) id 117bVr-0003X4-00 for rsgb_lf_group@blacksheep.org; Fri, 23 Jul 1999 10:21:07 +0100 Received: by gatekeeper.vs.dasa.de; (8.8.8/1.3/10May95) id LAA19429; Fri, 23 Jul 1999 11:22:15 +0200 (MET DST) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from somewhere by smtpxd Received: from somewhere by smtpxd Message-ID: From: "Koenig, Wolfgang" To: rsgb_lf_group@blacksheep.org Subject: AW: LF: 22. july Date: Fri, 23 Jul 1999 11:21:05 +0200 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2448.0) Content-Type: text/plain; charset=iso-8859-1; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org Sender: > ---------- > Von: Mike Dennison[SMTP:mike.dennison@rsgb.org.uk] > Antwort an: rsgb_lf_group@blacksheep.org > Gesendet: Freitag, 23. Juli 1999 10:29 > An: rsgb_lf_group@blacksheep.org > Betreff: Re: LF: 22. july > > DL1SAN wrote: > > > > Yesterday I installed abt. 20 radials (10-35m) to my antenna system. But > > there was no significant change of the antenna current. The current is > abt > > .6 A with and without the redials. Can anyone explain this? > > > > It is possible you have altered the impedance of your system and > need to re-match it to the Tx. > > The radials did not change the tuning significantly. For a better understanding i try to describe my antenna and tuning circuit. Form the wall feedthroug a 8m long wire ( 2 in parallel 30 cm apart) is fed to a mounting point of the chimney which is abt 9 m over ground. There an inductor with abt 1mH is installed. From the inductor three wires abt 10m long are tensed in 3 different directions. the ant is tuned with a fixed inductor, abt 2 mH, and a variometer for fine tuning. For exact tuning the antenna current and voltage is measured. Also the phase angle of current and voltage is monitored to find the "real" tuning point. With the same tool foreward-, back power and the phase can be measured. Former I did these measurements with an oscilloscope and a current coupler . Last month i built a power-amp,volt meter with phase measurement capability. This is smaller than a oscilloscope and more useful for portable operation. I hope this will answer a few open questions. 73 de Wolf (DL1SAN) > Mike, G3XDV (IO91VT) > http://www.dennison.demon.co.uk/activity.htm > >