Envelope-to: dave@picks.force9.co.uk Delivery-date: Wed, 18 May 2005 22:30:33 +0100 Received: from pih-spamcore03.plus.net ([192.168.71.7]) by pih-mxcore07.plus.net with esmtp (PlusNet MXCore v1.0) id 1DYW7d-0008SP-EW for dave@picks.force9.co.uk; Wed, 18 May 2005 22:30:33 +0100 Received: from Debian-exim by pih-spamcore03.plus.net with spam-scanned (Exim 4.50) id 1DYW7c-0003oU-TL for dave@picks.force9.co.uk; Wed, 18 May 2005 22:30:33 +0100 Received: from [192.168.101.72] (helo=pih-mxcore06.plus.net) by pih-spamcore03.plus.net with esmtp (Exim 4.50) id 1DYW7c-0003oR-RT for dave@picks.force9.co.uk; Wed, 18 May 2005 22:30:32 +0100 Received: from post.thorcom.com ([193.82.116.20]) by pih-mxcore06.plus.net with esmtp (PlusNet MXCore v1.0) id 1DYW7c-0000vt-Lx for dave@picks.force9.co.uk; Wed, 18 May 2005 22:30:32 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1DYW76-0005zH-3a for rs_out_1@blacksheep.org; Wed, 18 May 2005 22:30:00 +0100 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1DYW75-0005z8-Iz for rsgb_lf_group@blacksheep.org; Wed, 18 May 2005 22:29:59 +0100 Received: from amsfep19-int.chello.nl ([213.46.243.20]) by relay.thorcom.net with esmtp (Exim 4.43) id 1DYW74-0000qx-43 for rsgb_lf_group@blacksheep.org; Wed, 18 May 2005 22:29:59 +0100 Received: from MARLEEN ([212.83.92.36]) by amsfep19-int.chello.nl (InterMail vM.6.01.04.04 201-2131-118-104-20050224) with SMTP id <20050518212950.PCOI25247.amsfep19-int.chello.nl@MARLEEN> for ; Wed, 18 May 2005 23:29:50 +0200 Message-ID: <001e01c55bf0$bc0574c0$245c53d4@MARLEEN> From: "PA0WFO" To: rsgb_lf_group@blacksheep.org Date: Wed, 18 May 2005 23:29:55 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-SPF-Result: relay.thorcom.net: 213.46.243.20 is neither permitted nor denied by domain of chello.nl Subject: LF: Fw: Re: Modification of the blower circuit and VFO drive for the ROPEX LF TRANSMITTER Content-Type: text/html; charset=windows-1252 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-Spam-Filtered: by PlusNet SpamCORE (v4.00s) Content-transfer-encoding: 8bit
Mal and the LF group ,
The problem is known Mal  (caused by the protection circuit which measures the current to the antenna terminal ) but as the total resistance in my antenna system is 65 Ohms I can connect my loading coil in series with the antenna and still have a good match . The RX is protected against statics by the two antiparalel type 1N4007 diodes fitted over the RX terminals in the Ropex . Tnx for your reaction  hope to work you soon again with manual CW.
73,William PAØWFO
 
 
----- Original Message -----
From: hamilton mal
To: rsgb_lf_group@blacksheep.org
Sent: Wednesday, May 18, 2005 7:37 PM
Subject: LF: Re: Modification of the blower circuit and VFO drive for the Ropex Lf Transmitter 
 
A good article on the Ropex William. It is a very useful TX for LF considering its size. I have been using mine recently and it performs very well considering the low power, although I have a good LF antenna system.
One thing to mention, if you use a grounded antenna matching system for 50 ohms at the base of the antenna the Ropex will not work on the high pwr setting, this is a well known problem but it can be overcome by using an extra LPF at the antenna output socket feeding the 50 ohm coax to the antenna.
73 cul de Mal/G3KEV