[Boatanchors] Kilowatt Match box vs Palomar AT2KD

[Rob Atkinson]

You absolutely should use the Matchbox but it may need some cleaning
up first.  Don't just hook it up without firstly removing the cover to
see how it is inside.  If you have the kind with the vswr bridge, I
advise removing the coupler and disconnecting the meter by removing
the cable to it to make it easier to open up the box.   Actually you
can just run it without the cover.   Nowadays the meter isn't
necessary if you can adjust the box with a vswr analyzer before
putting higher power to it.

It may have the arrangement inside it with the open frame T/R relay
for a sequenced antenna switch over from rx to tx along with the 300
ohm antenna rx lead on the link.  Usually none of this is needed now
if you have external sequencing so you can just leave the relay and
selenium diode alone and run strap right from the input UHF jack to
the link.

What works well is to position the match box right near where the open
wire line makes its entrance into the shack from outside.  That way
you only have a foot or two of parallel line inside the shack.

The Palstar unit sounds like another tuner designed for unbalanced
line with a balun thrown in so they can claim it works for balanced
line--it doesn't.    Correction--it doesn't work well.  The currents
on the line won't be balanced.

Once you seen inside the KW Matchbox you'll see that modern tuners are
made of inferior parts.  EFJ in its day manufactured RF parts for
broadcast--no dinky wire inductor stuff -- this tuner was made for KW
input AM.

73
Rob
K5UJ

> >
> > If I did use the Matchbox, would it be necessary to bring the ladder line into the shack?
>