Return-Path: X-Spam-DCC: paranoid 1102; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, FORGED_RCVD_HELO autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id t9EBghZ0008211 for ; Wed, 14 Oct 2015 13:42:43 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ZmKKj-0003JU-GL for rs_out_1@blacksheep.org; Wed, 14 Oct 2015 12:35:01 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ZmKKi-0003JJ-W1 for rsgb_lf_group@blacksheep.org; Wed, 14 Oct 2015 12:35:00 +0100 Received: from smarthost01a.mail.zen.net.uk ([212.23.1.1]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1ZmKJh-00078Q-JL for rsgb_lf_group@blacksheep.org; Wed, 14 Oct 2015 12:34:59 +0100 Received: from [82.70.254.222] (helo=OfficeWin7.lan) by smarthost01a.mail.zen.net.uk with esmtp (Exim 4.80) (envelope-from ) id 1ZmKIu-0003iU-P1 for rsgb_lf_group@blacksheep.org; Wed, 14 Oct 2015 11:33:40 +0000 Date: Wed, 14 Oct 2015 12:33:07 +0100 From: Chris Wilson Organization: Gatesgarth Developments X-Priority: 3 (Normal) Message-ID: <603371935.20151014123307@chriswilson.tv> To: Alan Melia In-Reply-To: <43464DACBFAA49C08A73FB93FFF52105@gnat> References: <1541636554.20151013163425@chriswilson.tv> <43464DACBFAA49C08A73FB93FFF52105@gnat> MIME-Version: 1.0 X-Originating-smarthost01a-IP: [82.70.254.222] X-Scan-Signature: fc152e7304849b9a177649b85aea9f41 Subject: Re: LF: Re: Should I be aiming for a better match than this? Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 4367 Hello Alan, Tuesday, October 13, 2015 >>>can i work out the antenna current from this? > Not really this is the current in the coax. If the current and voltage are > not in phase then by definition you have reactance in the coax termination. > You should try adjusting the variometer for current and voltage in phase > (that is resonance) , then adjust the turns ratio on the transformer to > match the resultant aerial resistive component to the 50ohm coax (if > possible :-)) ) That should give you optimum performance. > The reactive load may be what is tripping the protection it will give bigger > voltages(or currents) than the matched condition. > Whilst you have been getting a signal out, I suggest the next experiment is > to try and reducethe ground loss before you spend a lot of time getting a > perfect match to an imperfect aerial system (only to have to do it all again > when you manage to get the ground loss down.) > Alan > G3NYK Thanks Alan, appreciated as always. I may be doing something wrong as I can't seem to get the phase right, I will try later when my pal is free again. When he turning the variometer coil either way even by tiny amounts the phasing seems to go either side of matched, but I couldn't see a perfect match on the scope, which seems rather odd. I intend to try reducing ground losses, but it must be done discreetly, the wife gets worried when she sees me carrying large coils of wire into "her" garden ;) She talks of the place looking like GCHQ... Now what's wrong with that? ;) -- Best regards, Chris mailto:chris@chriswilson.tv