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Re: Pwr<>Antenna

Posted by Vic K2VCO on May 26, 2005; 6:30pm
URL: http://elecraft.85.s1.nabble.com/Pwr-Antenna-tp378766p378774.html

[hidden email] wrote:

> Quoting K2VCO:

>> Let's say you have a 1.5KW amplifier. Overall efficiency might be
>> 50%, so it >draws 3KW key down.

> What does it draw key-up?

Not so much, if it's instant-on, solid state with temperature-controlled
fans like the KPA800. But you are correct for a 'traditional' tube
amplifier.  Especially one that isn't instant-on and tends to be left on
for long periods.

>> SSB will be cheaper.
>
> How do you figure? The duty cycles are about the same. SSB may even
> have a higher duty cycle if you turn the processor on.

I was assuming a duty cycle of 33% for SSB.  Yes, I did not take heavy
processing into account!  But I think that without processing the duty
cycle for ssb is definitely lower than CW.

> btw, the duty cycle of CW is about 44%: Consider the standard word
> "PARIS". With all the spaces, it's 50 time units long. But the key is
>  down only 22 of those times.

Also most operators use long spaces between sentences.  I assumed 50% as
a worst case.  And don't forget that I left out one of the 50%'s from my
calculation!

--
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco

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