[Milsurplus] GRC-9 bedside reader

[Richard Brunner]

Re:
"  According to an article I read in Signal a number of years ago the
vibrator unit did not stand up well in 24 volt operation."

I think the big VB-16 vibrator didn't like heavy starting current on 24
volts.  There are two PE-237 schematics labeled "late," and "early."
Unfortunately they are mislabeled; the one marked "late," (Fig 172) is
actually "early," and the one marked "early," (Fig 171) is actually "late."
The difference is the "late" version has a soft-start circuit for 24 volts,
consisting of relay #743 and 3.1 Ohm resistor #740.

I worked on one PE-237, and after replacing all the buffer condensers and
cleaning all the vibrator contacts, it ran very well.  The VB-16 vibrator
has a nasty buzz, but with the lid on it is quite tolerable.  The voltage
regulating transformer #701 which provides regulated filament voltage works
very well, and is much better than the ballast resistor tubes in the other
power supplies.

Richard Brunner, AA1P