Rick - DJ0IP / NJ0IP wrote:
As a rule of thumb for estimating, it simply to take 50%.
A 1500w MFJ Matchbox rated for the old SSB rating system is really a 750w
matchbox.
Their 3000w Matchbox can handle 1500w if the SWR does not get too high.
That sort of specmanship is troubling. Depending on what is 'too high'
with regards to SWR. Most folk don't need a matchbox unless their SWR
IS too high. A matchbox that cannot handle 'high' SWR is a useless
appliance. In fact, if the requirement for 'low' SWR is low enough, a
little tweaking of the antenna might be in order making the light duty
matchbox unecessary.
The most deceptive amplifier power spec that I can remember is one
claiming 1KW PEP INPUT. I guess they were hoping the buyer would
confuse that with a 1kw amp. One of the best ways to judge an amp is to
look at what it is using for finals. The same goes for matchboxes
except now we are looking for capacitor voltage ratings and/or plate
spacing.
For my money I will stick with my old Johnson KW matchbox.
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