[Antennas] From transmission lines to tuners

[Steve L.]

> A KW into a tuner with 60% loss means that the tuner
> must dissipate
> 600 watts - not likely.

This has been my 'bull$hit' touchstone for many years.


My Alpha 99 with the optional cooling fan can TX a
continuous 1500W output forever. I've sent 5-6 minute
continuous RTTY transmissions at that power level many
times over a few hours... and I can't feel any rise of
temp in the transmatch except the ferrite balun. I can
easily leave my hand firmly gripped onto the balun and
wires after that transmission.... meaning we are
dealing with what, 25W? Out of 1500?

I do use a massive edge-wound silver-plated rotary
inductor from Pal Star (get one, they rock!) and real
antennas of the proper size for the band -- not 1/10
wavelength things and I homebrew my baluns from really
big wire and lots of cores.

Not that crappy efficiency can't happen, it can, but
when you can't feel any heat rise inside the
transmatch it's a big hint. Try holding onto a 100W
incandescent light bulb! (don't).

rant off

73, Steve N4SL

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