Only thing is the KW Johnson is rather inflated pricewise
these days. I am trying to stay within a budget. I understand
that since the 250 Watt Johnson was used for AM that it could
probably handle 600 Watts of SSB or even CW, this is what I
have seen posted by perusing through Google searches. What
are the limits powerwise of this smaller Matchbox?

That's going to depend to some extent on the characteristics of the
load. Very low, very high, or very reactive loads can be difficult
for a tuner to handle - they can result in high voltages (the
capacitors or the output connectors may arc over) and/or high
circulating currents (high losses in the inductor, leading to
heating). A tuner might misbehave into some loads, at power levels
where it'd have no difficulty at all into easier loads.

Are linears such that
you "select" how much power, so even if the linear is capable
of more than the matchbox, I could experiment to see how much
the matchbox would handle.

Depends on the design. Some may have adjustable gain, some may have
an adjustable input attenuator. Others are fixed-gain and you'd need
to reduce the RF power output from your exciter/transmitter in order
to make a proportional reduction in the linear's power output.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
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