>G'day,
>
>Found this ad on
>http://swap.qth.com/c_misc.asp?startnum=10&data=category,MISC,MISCELLANEOUS
>
>**3-500Z Filament to Grid Short Fix**
>Does anyone know if a 3-500Z tube experiencing a filament to grid short can
>be "fixed" ?
? We used to unshort them with our 11g centrifuge. However, only about
1/3 of the 3-500s were salvageable due to a grid-fil leakage problem that
sometimes accompanied the parasite which bent the filament helix
horizontally and caused the short. Also, if the fil and grid were welded
together by the osc, the tube is history. This is the price of not using
grid fusing and a glitch resistor after the HV filter cap.
- R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
www.vcnet.com/measures.
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