ORIGINAL MESSAGE:
On Thu, 10 Dec 2009 17:20:35 +0000, Rick Stealey <rstealey@hotmail.com> wrote:
>
>I have an Alpha 89 I am selling here for a friend who is no longer able to use
>his equipment. I have a sale pending but the buyer is sceptical about the
>condition of the finals. I have carefully tuned it up on all bands into a
>Bird load with a Bird wattmeter, 2500 watt slug. Typical readings are 2500
>volts, 1 amp, 60 ma grid current, and 1600-1700 out with 50 watt drive.
>Increasing drive a little gets more grid current, but peaking the tune and
>load for max out doesn't improve things. Power out doesn't sag. It's as if
>there was a governor on the amp !
>Some say that amp should produce an easy 2200 watts and the tubes are soft.
>If so what kind of life could be expected from them? A tough question I know,
>depends on the use. So maybe in percentage terms could it be estimated how
>much of the original life is left?
REPLY:
It sounds like the tubes have lost some emission, but as long as it produces
more than legal limit output, so what? Brand new tubes start losing emission the
minute you start using then. I would discount the price of the amp a couple
hundred bucks and go with that. If the purchaser wants brand new tube
performance, let him buy some brand new tubes. You'll find a buyer eventually.
73, Bill W6WRT
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