External 3B1 Monitor Project Status; and help needed

Bill Mayhew wtm at uhura.neoucom.EDU
Mon May 6 01:39:12 AEST 1991

Horizontal width is virtually always controlled by an inductor, not
a pot.  Check in the vicinity of the flyback transformer.  There
should be a cardboard tube about 10mm in diamter and 30-40 mm in
length with a large bolus of litz wire near the top.  The width is
controlled by moving a powdered iron slug up and down inside the
tube (hence changing the reluctance of the coil).  Adjustment is
accomplished via a plastic hex wrench.

The coil should have a profile something like this:

                 __| |__
                 |     |  <- coil
                 |     |
                 --| |--
                   | |  <- cardboard tube
                   | |
                  _|_|_       <-  circuit board

As far as delaying the video.  Hmmm.  I don't know.  Perhaps the
width adjustment will take care of that?..


Bill Mayhew      NEOUCOM Computer Services Department
Rootstown, OH  44272-9995  USA    phone: 216-325-2511
wtm at uhura.neoucom.edu   ....!uunet!aablue!neoucom!wtm
via internet: (

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