On Tue, 2008-07-22 at 14:07 -0700, Jim WA9YSD wrote:
> For what its worth. Johnson match box was very popular in its day. So
> people could not get it to work on 10M because of what ever. To long
> antenna, feed line issue what ever. Inductance was the problem. Maybe not
> tight enough coupling? I cannot remember any more.
> Too much capacitance causing this?
Yes. The match box always has the two differential capacitors across the
tuned winding and they can't be small enough to work good at ten meters
and be big enough for 80 meters.
My ten meter tuners are about 3 x 4 x 5", way smaller than the Viking
Matchbox and capable of as much power. Coil is only an inch in diameter
and maybe an inch and a half long. Main capacitor isn't much bigger.
Dual 50 pf is plenty big.
> Just sounds like inductance issue. You have the test equipment so my guess
> must not be a good one.
> Tight coupling, I do not think I could achieve that with this 253 auto tuner.
> I may have to play with my old MFJ.
> Keep The Faith, Jim K9TF/WA9YSD
73, Jerry, K0CQ
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