[AMPS] L7 now working, have ops question

[George T. Daughters]

hi steve,

you wrote....

> With line voltage at 243 VAC, 2650V on the plates, and 100W drive,
> my peak output power is:
> 
> 160, 80, 75 and 40 Meters, about 1150 watts
> 30 through 15 meters, about 1 kW
> 12 and 10 meters, about 900 watts. (drive power may be off a bit on 10,
> using an IC756 running at 13.4 V, no DC sag, but not always a full buck)
> 
> Average plate current, 320 mA.
> 
> Is this about right? 

hmmm.  2650 v @ 0.32 a = 848 watts from the HV supply, and say 100 of 
so-called "feed thru" power from the 756 exciter = 948 watts...

and you're getting as much as 1150 out!!  i'd say it's 
working really well!  the efficiency is over 100%!  

that, or some measurement(s) are a ways off!  as a really rough rule 
of thumb, you ought to get about 60% efficiency with a linear amp.  
if it's below 50%, there's something wrong, and if it's much above 
60%, then it's probably not linear.  now don't everybody jump all 
over me, please!  i said "really rough rule of thumb."

but 1000 to 1150 out from two tubes whose combined dissipation is 
1000W is not too far from the correct ballpark.

73,

George T. Daughters, K6GT

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