On Apr 7, 9:48*pm, "
wrote:
Amazing Barry and you are astonishingly right! A detailed calibration
guide is presented here.

http://bama.edebris.com/manuals/hickok/533%28a%29/

However, while the 533A has a good parts list, only the transformer is
specified being possible COTS. I think I read somewhere that the
dynamic mutual conductance test was rather proprietary here? Well, I
have roughed in these parts by only using a hand wound guesstimate.
The original parts where in such bad shape that the number of windings
could not be counted from the shape I received this unit in. BTW I
used a micrometer to center in on the wire gauge which seemed rather
sensible to me.

One of the repairs I did was rather precise though. I sub'ed in a 5K
pot given below and shunted it with a 7.5K resistor to correct for a
solidly seized BIAS pot. 3K on the nose too... and it works just
dandy.

http://uk.farnell.com/colvern/clr400...-7-5kohm-3w-5/...

These parts can also be imported through Newark. The lead time on the
pot was rather insane though when they were not in stock

I appreciate all your help guys. I would have thought this coil
information would be easy to come by after all this time? While this
unit is testing out triodes well (eg. 12AX7), it is not giving me
impressive results on a tetrode (EL84/6BQ5) or a beam power tube
(6L6). Something is fishy here because I otherwise believe at least
the 6L6 is good. Sounds like a real cal problem here to me!!!!!

Take care and many thanks.

Fabe
CBS, Newfoundland, CA


Unfortunately that won't work for this pot. It was made with a special
taper and only an original will work.