Received-SPF: neutral (google.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org)
Message-ID: <20070521222332.grmmadm1jf48ssg0@webmail3.kuleuven.be>
Date: Mon, 21 May 2007 22:23:32 +0200
From: Rik Strobbe <Rik.Strobbe@fys.kuleuven.be>
To: rsgb_lf_group@blacksheep.org
References: <000701c79bce$99ad2ce0$72e4fc3e@g3kev>
In-Reply-To: <000701c79bce$99ad2ce0$72e4fc3e@g3kev>
MIME-Version: 1.0
Content-Disposition: inline
User-Agent: Internet Messaging Program (IMP) H3 (4.1.2)
Subject: Re: LF: Distance
Content-Type: text/plain;
	charset=ISO-8859-1;
	DelSp="Yes";
	format="flowed"
Content-Transfer-Encoding: quoted-printable
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Status: O

Why would one need an "antenna farm" with an ERP (EIRP ?) limit of 0.1 Watt?
Even a small backyard antenna such as a 8 m high and 8 m topload =20
T-antenna has a radiation resistance of about 0.15 Ohm.
Taking into account a gain of 2.63 dBd (4.78 dBi) the antennacurrent =20
needed for 0.1 W ERP is only 0.6 A and for 0.1 W EIRP even only 0.47 A.
Assuming a loss resistance of 40 Ohm the required TX power is 15 W =20
(for 0.1 W ERP) or 9 W (for 0.1 W EIRP).

So there is no advantage using big antennas , except that you will =20
need only 1 W TX power instead of 15 W. At least if you stick to the =20
0.1 W ERP limit.
On the other hand using narrowband modes will give easily give a 5 to =20
10 dB improvement of CW.

73, Rik  ON7YD

Quoting hamilton mal <g3kev.ham@virgin.net>:

> Hi All
> There is no need to use QRS to be heard/seen around EU. Uk stns have been
> heard around EU on normal CW especially after dark. GI4DPE and myself G3KE=
V
> have been hrd in Spain/Italy and YU but to mention a few places.
> Concentrate on CW and your antenna farm and avoid Lazy Mans cw.
>
> de Mal/G3KEV
>
>
>
>


Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm