A scope CRT for an IWATSU SS-3310 portable scope. The original
tube works but has loose parts inside that damaged a mesh electrode. The loose
parts are about 4 mm and 2 mm in size. The phosphor has dints, too. The scope works,
but the screen image appears distorted.

The scope is from the early 1990s and Iwatsu from Japan did not respond at all to service request.

Screen glas width   7,45 cm
Screen glas height   6,20 cm
Overall length 27,35 cm
Deflection pins from front
17,20 cm
The tube has a rectangular screen with grid printed inside. It has a 14 pin socket,
4 side pins for deflection and a HV connector (acceleration).
Connector pins for horizontal deflection plates and the label are at the bottom.
Pins for vertical deflection plates and acceleration HV at the right side when looking at screen.

Type 95 probably means about 95 mm diameter, in fact the 91 mm.
31 is a standard green phosphor.
Deflection amplifiers work from 43 V, so the deflection constant is something like 10 V/cm horizontal.

If you have a spare CRT or a broken SS-3310 with a good CRT, please offer to
dieter (at) cadt (dot) de. If you know of a similar CRT that may fit, please inform. For example
the Tektronix SC502/SC504 CRT is a near hit, except its screen glas is a little wide and high,
and the deflection pins are mirrored. Thanks!

Images of defective original tube:
label detail

side view

gun detail

screen detail

Distorted screen image (typical):
screen distortion

November 2011
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