[Amps] Should a blower run after amp shutdown?

[Jim Tonne]

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.  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