From: "Mike Dennison" <mike.dennison@rsgb.org.uk>
To: rsgb_lf_group@blacksheep.org
Date: Mon, 19 Feb 2001 10:03:17 -0000
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Subject: LF: It's L at the top
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On Sunday I increased the inductance at the top of my mast. I 
replaced 3mH of Litz wire with 7mH of ordinary wire. This made the 
antenna almost self-resonant. In fact, I needed a 6800pF capacitor 
(very heavy duty oil-filled, from the Puckeridge Decca site) in series 
with my 0.5mH variometer to tune it.

As expected, the current dropped - from 2.7A to 2.2A - as the point 
of maximum current went higher up the mast. 

There have been no measurements yet, but initial results seem 
good. I received the best ever reports from GW (599), GM (589) 
and SM (579), and worked DJ9IE (559) who had never replied to 
my calls before.

An all-night transmission using 30s dots on 135.9235kHz did not 
seem to cause any trouble, so all seems stable.


Mike, G3XDV (IO91VT)
http://www.lf.thersgb.net