Carter Grabarczyk wrote:
I am using a Johnson KW Matchbox antenna tuner with a 130 foot long,
30
foot high dipole fed with about 40 feet of ladder (window) line. It
works well on all bands including the WARC bands *except* for 30
meters.
(it doesn't make any difference if the band switch is on 20 or
40--it
will not tune 30 in either case).

The question is, does anyone have any tips/suggestions/modifications
to
make this also operate on 30 meters?

By the way, modifying the antenna is not an option--lucky to have it
up
at all with city and subdivision restrictions. Maybe could add extra
ladder line in the basement shack, but would have to loop it around
the
basement ceiling???

73,
Carter
K8VT
Hi Carter, That's a very high impedance you are trying to match on
30m. Looks like the only options you have are modifying the Matchbox
or changing the Feedline lenght. Another poster gave some good ideas
on modifying your tuner. If you don't want to modify the tuner, then
feed the 130' dipole with 11.3' of 450 ohm line and then go 50 ohm coax
to the transmitter. Don't need a tuner. Or if you could lenghten to
ladder line to 56' that would give a good 50 ohm match, no tuner
needed.
This is a guess but I think you would need to lenghten or shorten the
ladder line 8-10' to get within range of the Matchbox.
Gary N4AST