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Old 02-16-2017, 11:42 AM
DavGoodlin's Avatar
DavGoodlin DavGoodlin is offline
Motorola Minion
Join Date: Aug 2011
Location: near Strasburg PA
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Remove shorts using B&K 445

Does the ""REMOVE SHORTS"" function blast only grid to cathode shorts? Or does it tie heater and grid together and blast a short on BOTH sides of the cathode?

I have a very strong 21FJP22 RCA colorama replacement and it has a heater-cathode (H-K) short on the blue gun only. Using an ohmmeter between pins 13 and 14, indicates a 3.1 ohm short that goes open only when neck is gently tapped.

I plan to use a 6.3 volt 2 amp transformer for isolation if is too risky. BUT, I know from experience that this adds stray impedances to an other wise good video signal fed to the blue cathode.
"When resistors increase in value, they're worthless"
-Dave G
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Old 02-16-2017, 03:44 PM
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bandersen bandersen is offline
Restoring Admiral T2301
Join Date: Mar 2009
Location: Chicago, IL
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I don't think there's really any way to safely clear a heater cathode short. I've seen some sets use a type of brightener that is a 1:1 isolation transformer as a workaround.
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