Topband: 40 foot circumference shielded loop

[Ford Peterson]

Oops,  I said diameter but meant circumference!  My mother always said,
don't listen to what I say, listen to what I mean.

The 12.5 foot diameter, 41 foot circumference loop does work on 160 but not
on 80.  After playing with my match today, I am pleased to report the
following:

Unmatched...

1.8    9    +j550
1.9    54   +j715
2.0    245  +j910

3.5    5    -j203
3.6    7    -j192
3.7    7    -j179
3.8    8    -j169
3.9    11   -j160
4.0    10   -j150

7.0    5    +j6
7.1    8    +j8
7.2    7    +j18
7.3    9    +j24

It does match on 1811 at about 26  j0 with about 130 pf of capacitance.  The
match on 40 appears to be workable but have not tried it yet.  On 80, all
bets are off.  There does not appear to be a way to introduce inductance to
counteract the capacitive state on 80 meters.

Anybody got some ideas?  Shorten it and the match appears to be less
manageable on 160 and 40.

Ford - N0OQW


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