Dear Mike, LF group,
I think the feed point impedance of the shunt-fed mast will be a fairly low
inductance in series with a loss resistance of a few ohms due to the feed
wire and mast - essentially similar to a loop antenna. It would require a
series capacitor to get resonance, plus a step-down transformer to match the
TX load impedance. The trouble is that the impedance transformation produced
by the shunt feed will convert the tenths of an ohm radiation resistance
into micro-ohms at the feed point, which will just be lost in the loss
resistance of the feed components.
Cheers, Jim Moritz
73 de M0BMU
----- Original Message -----
From: Mike Dennison <[email protected]>
To: <[email protected]>
Sent: Sunday, July 18, 2004 10:25 AM
Subject: LF: Feeding grounded tower on 136KHz
There has been lots of comment on how difficult it would be
to shunt match a grounded tower, but no-one has
commented on how to resonate the antenna. It seems to
me that the matching is the easy bit.
Mike, G3XDV
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