[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Positonal Hum

Our MKIII/C is exibiting a problem that has been preplexing
with the following solution recommended by Rank L.A.:

Most visible with the SMPTE "Registration chart" (the one with
horizontal and vertical lines) is a shaking of the horizontal
lines with a scrolling upward of the effect.  Rank called this
"positional hum".

The problem seems to stem from the 70 volt supply in the scan and
Signal Power Supply as it is a very hummy source of power.

The solution, as recommended by Rank, is to replace the
unregulated 70 volt supply, in the Scan and Signal Power
Supply, with a regulated supply supplying a no hum source
of power to the Line Timebase and EHT power supply cards.

This all sounds correct but before I build such a supply has
anyone found this true and is there a power supply availiable
(what does the Turbo do about this)?


Alan Burnham
WickerWorks Video