[Amps] PowerGenius XL Video

[Jim Thomson]

Date: Fri, 10 Feb 2017 17:52:14 -0600
From: Kevin <kstover at ac0h.net>
To: amps at contesting.com
Subject: Re: [Amps] PowerGenius XL Video

No way a pair or trio of 3-500Z's does 1500W FM/RTTY key down all day.

An 8877 won't do it either without having a very big, very loud blower.
 
R. Kevin Stover
AC0H
ARRL
FISTS #11993
SKCC #215
NAQCC #3441

## Art bell told me his cat fell asleep on the footswitch, while he was out doing errands.
He comes back to his shack full of smoke, and the poor alpha 87-A had been sitting there
on 10M FM,  putting out 1.5 kw for 2-3 hrs non stop.   He phones up alpha and asks the
tech about the... no time limit spec.  Tech tells him...not to believe the advertising hype. 
The PI-L had overheated and half come apart, amongst other things.   But thats a one off case.

##  The power genius would indeed swap bands back and forth, using a single flex xcvr, so it
will  do SO2R, with just one amp..and one xcvr.   Now that will work ...provided the swr
on each band is either flat, or very low.  IF you had separate feedlines to each ant, then at least
you could install a dedicated manual tuner in each feedline.  If not, then an automatic 2 kw rated
tuner is required.   I have not seen any 2 kw rated automatic ant tuners that will swap bands in 
a split second.  Provided the swr was ok, the power genius would save the expense of a 2nd amp. 

##  Ill defer to Bill, as he is the rtty expert.  Does the typ xcvr operate  fsk or  afsk ?  You might be
able to increase the bias on a tube amp, and lower the idle current way down, when operating rtty.
Tank eff could be improved a little bit, reducing  plate dissipation.   If eff was as high as say 70%
running increased bias, to get 1.5 kw out would require  2143 watts dc input =  643 watts anode diss,
which is well within the specs of even a pair of 3-500zs, never mind 3 of em. 

## Loud amps can always  be re-located to the workshop next door in my case, but that is not always
feasible.  It also requires running in there to tweak them, or change bands etc. 

Jim   VE7RF