[Top] [All Lists]

Re: [Amps] Should a blower run after amp shutdown?

To: "Jim Tonne" <Tonne@Comcast.Net>, <>
Subject: Re: [Amps] Should a blower run after amp shutdown?
From: "Jim Thomson" <>
Date: Fri, 3 Jun 2011 08:05:04 -0700
List-post: <">>

From: "Jim Tonne" <Tonne@Comcast.Net>
Sent: Friday, June 03, 2011 6:47 AM
To: "Jim Thomson" <>; <>
Subject: Re: [Amps] Should a blower run after amp shutdown?

> Gents:
> 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 
> reply:
>>  The screen voltage needs to come down first, with the drive at the same 
>> time.
>>  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 
>> filament
>>  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 ?

Jim  VE7RF

  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). 
>> All
>>  together, it takes about 10 to 15 minutes on the 500kW.
> I think that response would be of interest to the group.
> - Jim W4ENE

Amps mailing list

<Prev in Thread] Current Thread [Next in Thread>