Topband: MATCHING COIL QUESTION

BILL MCHUGH magoo@isp.on.ca
Fri, 13 Dec 2002 17:15:55 -0500


I am attempting to match my vertical after replacing the linear loader with
a 3-wire tophat.  I like to use an inductor to ground (for lightning) tapped
for 50 ohms.

I have a solution...but how do I know it is the RIGHT one?  By
experimentation with a 3" diameter coil of #12 wire, the 50 ohm tap point is
about 6.5 turns up from ground with the antenna attached about a turn above
that.  This gives me about 100 khz for 2:1 SWR points. The coil on the
previous antenna configuration produced a match at about 3.5 turns above
ground with the antenna 6 turns up from there.  Its 2:1 SWR bandwidth was
about 70 khz.

I'd guess that some soultions would result in better power transfer while
producing an acceptable bandwidth.

Any guidance or suggestions here from those in the know?

Bill, VE3CSK/VE3NH