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Old 04-19-2011, 10:05 PM
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Phil Nelson Phil Nelson is offline
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Originally Posted by Phil Nelson View Post
With a .1 uf cap in place, I measured 118ma cathode current with the Triplett meter. That's the middle of the 100ma-140ma range given in the schematic. I'm going to quit stressing over this, since the voltages on the HOT and general performance are also normal.
Speaking of current measurement, this week I got my hands on an HP 428B DC milliammeter, which gave the same reading as my old Triplett meter, so I guess the Triplett's good enough for government work.

Andy's method worked like a charm. Clip the 428B probe over the HOT lead and measure away. Easy as pie. On this set, the Width control affects the current directly, so I turned it down to around 100ma, which gives reasonable width & picture.

I got the 428B to use on my color roundies, but it has already earned back the few shekels I paid for it, and now I feel better about just letting this Philco play away. After warming up a couple of minutes, it looks fine without the CRT brightener, so I tossed that in a box. Who knows why they put on a brightener in the first place? Maybe that was a quicker solution than diagnosing some peskier issue.

Phil Nelson
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