Star Tech Journal

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CRT Analyzers /Rejuvenators
James Beck
Greater Southern Distributing
Atlanta, Georgia
CRT FAILURES
The CRT or picture tube is a very reliable and
long lasting component, but when one fails
it can be costly and time consuming to
replace. Most CRT failures are caused by
oxidation building up on the guns or loose
phosphorous falling down into the neck
area. Excessive oxides cause what is com-
monly referred to as a "weak" tube. Loose
phosphorous and other debris can cause
shorts to occur.
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CRT SOLUTIONS
Fortunately these problems can usually be
diagnosed and corrected with a CRT ana-
lyzer /rejuvenator.
HOW AN A/R WORKS
What a CRT analyzer/rejuvenator will do is
allow you to power up and dynamically test
for heater and grid leakage along with how
well the guns emit elections. If a failure is
diagnosed, there are methods to correct the
problem. If a short is found, a large pulse of
current can be applied to blow it open. Low
election emission is corrected by overheat-
ing the guns then passing a large amount of
current through them. This literally boils the
guns clean. Many tubes that appear to be
completely dead can be brought back to life
by doing this.
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LOST CAUSES
What a CRT analyzer/rejuvenator won't do
is repair burnt phosphor. It won't fix an open
heater element. It won't work on a tube that
has internal elements that have come loose.
A CRT analyzer /rejuvenator can work won-
ders on most weak or shorted tubes, and just
two or three repaired tubes will pay for the
cost of the unit.
Fabtek Dead Angle
Volume Control
Fabtek Customer Service
Summit Amusement
St. Paul Minnesota
PROBLEM
Volume control not in the location stated in
the Dead Angle manual.
SOLUTION
Two different board layouts exists. The main
volume control is VR-4. On one version of
the board set this control is located at posi-
tion A,5, on the lower board. To the left of
three other controls.
On the second version of the board, VR-4 is
located at position A, 13 and the three other
previously mentioned controls have been re-
placed with fixed resistors. These controls
operate backwards to turn the volume up,
turn the control to the left.