[Elecraft] Duty Cycle of FT8 #Elecraft

[Victor Rosenthal]

I don't have a kpa1500, but I recall someone from Elecraft saying that
since the efficiency decreases when power is reduced, backing off the power
does not reduce the heat load.

Victor 4X6GP

On Fri, Nov 10, 2023, 16:28 Pete Smith N4ZR <pete.n4zr at gmail.com> wrote:

> I started operating FT8 while my KPA-1500amp was out for repair.  Now
> it's back and raising a question:
>
> Operating with just my K-3, set at 100 watts, I would see 100 watts
> indicated on its meter through the whole 15-second FT8 transmission..
> When I drive my amp, it only needs 30 watts for full CW power (on 24
> MHz),  but the amp indicates 1200 watts input for the whole FT8 transmit
> cycle.  I'm wondering if I should back off to protect the
> amp,considering the duty cycle is so high - on the other hand, the
> temperature reading profile of the amp seems to be pretty much the same
> as on CW.
>
> 73, Pete N4ZR
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