[Drake] Bringing a PS7 out of hibernation

[Bob Camp]

Hi

Bringing up a solid state regulated supply on a variac may or may not  
be a good idea. Regulator circuits sometimes do odd things at low  
voltage and high leakage current. Its definitely a *bad* idea with a  
switcher....

Another way to re-form capacitors: Pop them out of the supply, bias  
them up with an adjustable lab supply. You need something like a 1K  
ohm resistor between the supply and each cap. The resistor lets you  
monitor what's going on. It also protects things if there's a short.  
After they have been on a couple of days the leakage should be below a  
mili amp or two.

Bob


On Nov 8, 2007, at 9:26 PM, tav1 at vzw.blackberry.net wrote:

> Hi,
> I want to put my Drake TR7A back on the air after being down for 15  
> years.
> I know I should bring the voltage up on the PS7 gradually with a  
> variac to reform the capacitors.  Is there any prescribed method for  
> doing this, such as increasing the voltage by 5 volts for a certain  
> period of time? If so, what period of time for each voltage  
> increment? Perhaps I need to replace the caps?
> Is there anything I need to do with the TR7 to bring it back?
> Any advice is appreciated,
> Torry
> N3ANO
>
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