User's Manual

RANGE switch to the next higher position, and then adjust the
control until the correct voltage is indicated on the meter.
i. If the line voltage is high and it is not possible to adjust
the FILAMENT fine control to indicate the specified voltage,
turn the FILAMENT RANGE switch to the next lower position,
and then adjust the control until the correct voltage is indicated
on the meter.
17. Zero Adjustment of PERCENT QUALITY Meter
When the procedures in paragraph 16 have been completed,
adjust the PERCENT QUALITY meter to zero. This adjustment
should be made before testing any tube for transconductance
(GM) as follows:
a. Turn the GM-SIGNAL RANGE switch to the F position.
b. Depress the PRESS TO TEST P4 switch to its locking posi-
tion. Reset the controls to give the exact meter readings specified
in the METER SETTING columns of the tube test data roll chart.
c. Adjust the GM CENTERING control until the pointer of the
PERCENT QUALITY meter is set exactly to zero on the scale.
d. Release the P4 switch.
18. Short Test
a. Perform the operations described in paragraphs 15 and 16.
b. For the TV-2/U, aline the dot on the PLATE fine control with
the dot on the panel. For TV–2A/U and TV–2B/U, aline the
PLATE fine control pointer-type knob with the line index marking
on the panel. This assures that the correct voltage will be applied
to the short test circuit.
c. Turn the SHORT TEST switch slowly from the OPER.
position to V, W, X, Y, and Z, and back to OPER.; at the same
time, tap the tube with a finger and watch the FIL. CONT. SHORT
indicator lamp.
Caution: Do not tap the tubes listed below when testing for
short-circuited elements. Tapping may damage the tube.
1A5GT
1LH4
1A7GT
1LN5
1C5GT
1P5GT
1G4GT
1Q5QT
1G6GT
1S4
1H5GT
1S5
1L4 1T4
1LA4
1T5GT
1LA6
1U4
1LB4
1U5
1LD5 3A4
1LE3 3A5
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