Re: Need help with 561A


Morris Odell <morriso@...>
 

Or, if you
could find a 6.3 VAC, 600 ma filament transformer that could
stand to have 3300 volts applied to it without arcing to
ground, you could supply CRT filament power with a separate
transformer. I have never seen one of those transformers
either . . . I HAVE seen some good for 1500 volts, however,
so this solution will work in some other models of scopes
such as the the 530, 540, and 550 series.
I don't know what the situation is in the US but down here in Oz all the
little (Chinese made) transformers sold by the electronics parts houses
comply with a standard that specifies a 4 kV insulation rating. I have
used these for the CRT of a 543 and a 310A (admittedly a bit less less
than 3.3 kV) with no trouble at all.

It might be worth checking the transformers available these days in the
US.

Morris

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