On May 13, 2005, at 12:40 AM, John, KI6WX wrote:
At high power, an inefficient tuner can generate significant
amounts of heat, which can destroy components. A 1kW transmitter
into a 70% efficient tuner will generate 300 watts of heat in the
tuner.
This is why I tend to disbelieve tuner efficiency figures. From the
QST tests, there seem to be a lot of tuners than have losses greater
than 10% -- yet there is no evidence that any of these tuners heat up
appreciably! At 1 kW, a 10% loss is 100 watts -- imagine how hot a
tuner enclosure would get if you had a 100 watt light bulb inside it.
Even at 100 watts, 10% loss is 10 watts. That's still enough to
induce a few degree change in a small enclosure.
Bill Coleman, AA4LR, PP-ASEL Mail: [EMAIL PROTECTED]
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901
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