X-GM-THRID: 1209154499453586391
X-Gmail-Labels: rsgb lf
X-Gmail-Received: 35e7be97336d38d7ca5b32f67c7285b303eb074f
Delivered-To: daveyxm@gmail.com
Received: by 10.64.243.13 with SMTP id q13cs114059qbh;
Mon, 17 Jul 2006 05:33:11 -0700 (PDT)
Received: by 10.49.1.9 with SMTP id d9mr1912547nfi;
Mon, 17 Jul 2006 05:33:10 -0700 (PDT)
Return-Path: <owner-rsgb_lf_group@blacksheep.org>
Received: from post.thorcom.com (post.thorcom.com [193.82.116.20])
by mx.gmail.com with ESMTP id k24si1672709nfc.2006.07.17.05.33.10;
Mon, 17 Jul 2006 05:33:10 -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 1G2SDi-0000LR-R0
for rs_out_1@blacksheep.org; Mon, 17 Jul 2006 13:29:06 +0100
Received: from [193.82.59.130] (helo=relay2.thorcom.net)
by post.thorcom.com with esmtp (Exim 4.14)
id 1G2SDi-0000LI-5e
for rsgb_lf_group@blacksheep.org; Mon, 17 Jul 2006 13:29:06 +0100
Received: from hestia.herts.ac.uk ([147.197.200.9])
by relay2.thorcom.net with esmtp (Exim 4.51)
id 1G2SDd-0005Lv-1F
for rsgb_lf_group@blacksheep.org; Mon, 17 Jul 2006 13:29:05 +0100
Received: from [147.197.215.113] (helo=tucana.herts.ac.uk)
by hestia.herts.ac.uk with esmtp (Exim 3.22 #1)
id 1G2S9v-00008v-00
for rsgb_lf_group@blacksheep.org; Mon, 17 Jul 2006 13:25:11 +0100
Received: from [147.197.164.230] (helo=RD40002)
by tucana.herts.ac.uk with esmtp (Exim 4.44)
id 1G2S9p-00026a-7i
for rsgb_lf_group@blacksheep.org; Mon, 17 Jul 2006 13:25:05 +0100
From: "james moritz" <j.r.moritz@herts.ac.uk>
To: <rsgb_lf_group@blacksheep.org>
Date: Mon, 17 Jul 2006 13:25:04 +0100
Message-ID: <000001c6a99c$0848d120$e6a4c593@RD40002>
MIME-Version: 1.0
X-Priority: 3 (Normal)
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook, Build 10.0.4510
Importance: Normal
In-Reply-To: <010701c6a931$73f5d460$6501a8c0@eagles>
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2869
X-UH-MailScanner: No Virus detected
X-UH-MailScanner-Information:
X-H-UH-MailScanner: No Virus detected
X-UH-MailScanner-From: j.r.moritz@herts.ac.uk
X-Spam-Score: -0.6 (/)
X-Spam-Report: autolearn=disabled,AWL=-0.566
Subject: LF: RE: DFCW, power and time.
Content-Type: text/plain;
charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
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: 4892
Dear J, LF Group,
You wrote:
...I have an RF ammeter which shows almost no antenna base current from =
100=20
Watt transmitter output. To get the 2.85 Amps will require much more =
power.=20
I guesstimated about 410 Watts...
Going from 100W to 410W will produce just over double the antenna =
current,
so unless "almost no antenna base current" is about 1.4A, the power =
increase
will not in itself achieve your goal. If we assume for a moment that the
resistive part of the impedance of your antenna is in the range 25ohms -
100ohms, and the antenna tuner is reasonably efficient, the antenna =
current
should be in the range of about 1A - 2A with 100W TX. Being a big =
antenna,
one would expect it to be towards the upper end of this range.=20
So unless the antenna current you are seeing is 1A or over, it looks =
like
your antenna tuner is still not working properly. Most of the TX power =
is
being dissipated somewhere other than the antenna, probably in the tuner
components. A large increase in TX power will cause these components to =
get
a lot hotter, probably damaging them. So it is important to sort this
problem out before increasing the TX power.
Cheers, Jim Moritz
73 de M0BMU