From: "Jim Tonne" <Tonne@Comcast.Net>
Sent: Friday, June 03, 2011 6:47 AM
To: "Jim Thomson" <firstname.lastname@example.org>; <email@example.com>
Subject: Re: [Amps] Should a blower run after amp shutdown?
> I asked a former co-worker (WA5LFY) how our "big" rigs were shut down;
> he was still working on them after I left the company. Here is his
>> The screen voltage needs to come down first, with the drive at the same
>> Then the high voltage comes down. That prevents high screen current
>> which would
>> occur if the high voltage is removed first, leaving the screen to look
>> like an "anode".
>> With drive, screen, and HV removed, the bias supply can be removed, and
>> ramp-down can occur.
#### Notice how he ramps down the fil V....when done for the night . I'm
convinced that ramping down the fil V is less stressful on big fil's. It
certainly reduce thermal stress and shock. Emtron does the ramp up
if they do the ramp down part of it though. Does anybody know ?
After all of that, the cooling can be removed after
>> a brief
>> cool-down period (I used about 3 minutes to remove any residual heat).
>> together, it takes about 10 to 15 minutes on the 500kW.
> I think that response would be of interest to the group.
> - Jim W4ENE
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