[ARC5] Cap Test

[mac]

Aw come on, guys.  Just throw the switch and enjoy the adrenaline  
rush..... :^)

DD, W7QHO

***************
On Feb 8, 2011, at 5:46 PM, Robert Nickels wrote:

> On 2/8/2011 1:10 PM, J. Forster wrote:
>> 3. With the filaments OFF, slowly crank up the voltage to normal  
>> operating
>> voltage. If a cap is bad, the light bulbs will light.
> I do a similar technique but using substitute solid state rectifiers  
> and
> a mA meter, where possible to reform the electrolytics in-situ.   
> Either
> way, the secret is to have an indication of the current being drawn  
> from
> the B+ supply.   All the folklore floating around the internet about
> "bringing it up slowly on a variac" is apt to create just as many
> problems as it solves if done blindly.
>
> Another tip an old radio-TV repairman told me about can be done at the
> same time, and is a time-saver when working on receivers, audio amps,
> modulators, etc.   Pull all the tubes (perhaps running them past your
> favorite tester) and once you have the B+ safely  cranked up, use a
> voltmeter to verify the absence of DC voltage at the grid end of the
> coupling capacitors.    If the cap is leaky, voltage will be present,
> and if not you can generally assume the cap is OK.
>
> 73, Bob W9RAN
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