[Amps] Shorting Sticks

[Will Matney]

Exactly,

That's the very reason I added a volt meter on mine with a seperate ground. I've had to hit the button 2-3 times just to kill off any residual charge. I always start at the B+ line and then work my way across each cap watching the meter until I know it's dead. Then add a shorting wire from B+ to ground while I'm working on it, removing it to make measurements.

Thing is, if I were working on someones amp, what would one do, tell the customer I just ruined your caps by shorting them out and now one or all needs to be replaced? I'll bet they wouldn't pay the bill. That was why I made the discharger to do it safely and not destroy a component. Always has worked great for me. Also, preventative maintenance on the discharger, checking it after each few discharges for proper operation (remembering to put powder in those hot gloves is the same thing). If not for the voltmeter, one wouldnt be sure if they discharged or not. That holds true even with a shorting stick just like you mentioned. The best thing if using one would to be use a voltmeter afterwards to check for anything left before tipping a thing.

Back years ago in my TV days, discharging the CRT was a common thing. They made a shorting stick, but I always used my HV probe first. I'd wait until the meter showed zero, or almost, then use the stick to dead short the anode button to the aquadag. About 27 kV to now up to 30 kV aint nothing to get bit by.

Best,

Will

*********** REPLY SEPARATOR  ***********

On 4/24/05 at 5:57 PM TexasRF at aol.com wrote:

>There was one more "gotcha!" failure mode that comes back to mind: My 2m
>8877 
>PA hv power suplly uses two 100uf 3000v oil filled caps in series. The big 
>power bleeder resistor had gone open as mentioned previously so the
>shorting 
>device was applied to the plus and minu terminals to discharge the caps.
>
>Imagine my surprise when after shorting them, I found both capacitors
>still 
>had a hv charge on them! The shorting stick just made all those stored 
>electrons divide between the two caps.
>
>So, not only should the B+ to B- be discharged, each series capacitor
>should 
>also be discharged.
>
>You just can't assume anything when working with these hv circuits.
>
>73/k5gw
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