[TenTec] bringing up an old amp

[Steve Berg]

I would just get the new capacitors.  I once hooked up an old Johnson 
Thunderbolt and tried to get it to power up.  I let everything percolate 
for a while and then fired up the high voltage.  I wound up vaporizing 
the fuse elements and flash depositing them on the glass tubes of the 
fuses.  Then, I replaced all the caps with brand new ones.  Luckily 
nothing else blew up.

Steve WA9JML

Ken Brown wrote:
>>   
>>> Anyone have a quick link or a reference to the right way to bring up an 
>>> old amp power supply?  I have a variac for both 120 and 220, and I got 
>>> an old friend's Drake L4B, not used for at least 10 years (maybe more) 
>>> and nothing was apparently wrong when it was stored (he was looking for 
>>> chimney's of some sort).  I'd like to bring the power supply up so that 
>>> the electrolytic caps will work once again.  
>>>
>>>     
>> In theory bring it up slowly current limited to reform the capacitors.
>> But in my experience more have failed immediately than I've successfully
>> reformed. New electrolytics are more sure to work. More than one failed
>> electrolytic for me has filled the chassis with shredded foil and
>> electrolyte filled crepe paper. A really tough mess to clean up. Old
>> electrolytics don't get that chance anymore.
>>   
> Not used for at least 10 years, and the capacitors are certainly a lot 
> older than that. When you compare the cost and labor of buying new ones 
> and putting them in first, versus the cost and labor of cleaning up the 
> mess of exploded old capacitors AND buying new ones and putting them in, 
> I think the best choice is just to buy new ones and put them in first.
> 
> I wonder if you could fit an oil filled capacitor of similar capacitance 
> value and voltage rating in the same space, instead of using electrolytics?
> 
> DE N6KB
>>   
> 
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