[time-nuts] HP 5328 PSU nightmare...

[Bill Janssen]

J. Forster wrote:
> With tube gear, one fairly good way to reform the caps is either pull the
> tubes (label where they came from) or disconnect the filament supply, and
> then apply B+. You do need to check the schematic to make sure you don't
> overvoltage caps that would see an increased voltage w/o plate current.
> Also, cathode bypass caps may never see the reforming voltage.
>   
Good advice, but leave the rectifiers (80, 5Y3, 5U4 etc.) in their 
sockets :-)

Bill K7NOM

> For solid state equipment, the light bulb thing will limit collateral
> damage on simple rectifier-filter analog supplies. Switchers are more
> problematic.
>
> -John
>
> =============
>
>
>
>
>
>   
>> And vacuum tube equipment using indirectly-heated cathodes:
>> http://www.cpii.com/docs/related/23/Basic%20Tube%20Design.pdf
>>
>> "Operating techniques that are proper for filamentary tubes are not
>> necessarily
>> correct for tubes with indirectly heated cathode emitters. In
>> particular, the opera-
>> tion of cathode types at reduced heater voltage can be destructive to
>> the tube."
>>
>> Leigh.
>>
>> Mark Sims wrote:
>>     
>>> Be very careful powering up modern equipment on variacs and with light
>>> bulbs in series, etc.  You go through areas where the bias voltages, etc
>>> are in  the right place to cause serious damage.  Switching supplies can
>>> be particularly entertaining...
>>>
>>> ----------------------------------------
>>>
>>>
>>>
>>>       
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>
>
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