X-GM-THRID: 1211538136891779295 X-Gmail-Labels: rsgb lf X-Gmail-Received: 9cbbe5ab4f74fe7a6cb56bb29e71cc3be08c1094 Delivered-To: daveyxm@gmail.com Received: by 10.64.249.16 with SMTP id w16cs154099qbh; Sat, 12 Aug 2006 13:00:05 -0700 (PDT) Received: by 10.48.230.18 with SMTP id c18mr5198289nfh; Sat, 12 Aug 2006 13:00:04 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.gmail.com with ESMTP id x27si4850195nfb.2006.08.12.13.00.03; Sat, 12 Aug 2006 13:00:04 -0700 (PDT) Received-SPF: neutral (gmail.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1GBzcH-0006cN-IF for rs_out_1@blacksheep.org; Sat, 12 Aug 2006 20:57:53 +0100 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1GBzcG-0006cE-UE for rsgb_lf_group@blacksheep.org; Sat, 12 Aug 2006 20:57:52 +0100 Received: from smtp809.mail.ird.yahoo.com ([217.146.188.69]) by relay2.thorcom.net with smtp (Exim 4.51) id 1GBzcC-0003bs-JO for rsgb_lf_group@blacksheep.org; Sat, 12 Aug 2006 20:57:52 +0100 Received: (qmail 10619 invoked from network); 12 Aug 2006 19:56:43 -0000 Received: from unknown (HELO lark) (alan.melia@btinternet.com@213.122.62.54 with login) by smtp809.mail.ird.yahoo.com with SMTP; 12 Aug 2006 19:56:41 -0000 Message-ID: <001401c6be49$6d97e900$0300a8c0@lark> From: "Alan Melia" To: References: <003901c6be46$2f6871c0$33be3b3e@fujitsu> Date: Sat, 12 Aug 2006 20:56:36 +0100 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 X-Spam-Score: -0.7 (/) X-Spam-Report: autolearn=disabled,AWL=-0.741 Subject: LF: Re: Fw: PA4VHF small backyard tests Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.63 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 Status: O X-Status: X-Keywords: X-UID: 5966 Hi Dick, you have a big problem somewhere there I can get 200mA of antenna current with 2 watts RF . If you your TX is 80% efficient and generating abt 80w and your total resistance is measured as 60 ohms you should get 1.2 amps or close to that . 6.8 mH is way to low for that capacity which suggests you have a funny on the tuning maybe and interaction with the transformer. You could try tuning the antenna alone (no matching transformers) with the bridge, and see it it tunes in the same place. Cheers de Alan G3NYK ----- Original Message ----- From: Dick To: rsgb_lf_group@blacksheep.org Sent: Saturday, August 12, 2006 4:33 PM Subject: PA4VHF small backyard tests Well, changed the antenna and fired up my little teststation this afternoon in my backyard. Antenna: 3 wires 7.5m long spaced 40cm each , vertical part about 6m long also 3 parallel wires spaced 40cm each. Feed is about 2m from the far end. Measured about 170pF and 60 Ohm (?) with bridge, noisesource/136kHz oscillator and RX. With variometer and loading coil connected, I needed about 6,7mH to tune things, where I expected to find around 8,0mH. Somewhere I got around 30-40pF extra. Maybe internal capacity of the loading coils??? With 100Watt DC-input I got about 200mA antenna current sofar. Remarkable: when switching TX on/off, I could hear the first step-up transformer clicking (it's a 58mm 3C85 core) is this usual??? The transmitter used is my little testbox with an additional amplifier with IRFP360 running at around 12-14V, 6-9Amp. Mal has heard me before with this transmitter connected to a 15m spiral toploaded vertical.......... 73 Dick, PA4VHF (JO32eg)