Another vertical output transformer????

[Electronic M]

ESR is a poor safety test for original capacitors in a tube set because it does not check for leakage at full working voltage. To properly confirm the safety of those caps you need a Heathkit C-3 or one of the other eye type capacitor checkers of the time period.

I recently unwound the primary of a late 60's Zenith vert. Xfomer out of a monochrome set, and was surprised by the lousy (thinner than paper and brittle like onion skin) insulation between layers of the primary, and more surprised that they used the exact same crap between the primary (connected to B+) and the secondary (connected to ground)....I'll give you one guess what the failure mode was...