g. Set the ON-OFF switch to the OFF position.
32. Filament Voltage Test
h. Remove the 450,000-ohm resistor and in-
(B, fig. 22)
sert a 550,000-ohm resistor in its place.
a. Set the FIL switch to position 7.
i. Set the ON-OFF switch to the ON position.
b. Set the FIL + switch to position 2.
j. The PLATE meter indicates to the left of
c. Set the GM-SIGNAL RANGE switch to
the 0.5-megohm point.
position A and all other switches and controls to
their neutral or OFF position (vertical position
35. Short Test
for switches, extreme counterclockwise position
a. Set the tube tester up according to the tube
for controls).
test data roll chart, to test tube 6V6.
d. Connect the ME-30A/U between pins 2
b. Insert a 3,000-ohm resistor between pins 3
and 7 of the OCTAL tube test socket.
and 7 of the OCTAL tube test socket.
e. Set the ON-OFF switch to the ON position.
c. Set the ON-OFF switch to the ON position.
f. Set the FILAMENT RANGE switch to
d. The FIL. CONT. SHORT lamp glows con-
each of its 19 voltage positions, and adjust the
tinuously when the SHORT TEST switch is set
FILAMENT fine control for the exact corres-
to positions V, W, and Z.
ponding voltage on the FILAMENT VOLTS
e. Set the ON-OFF switch to the OFF position.
meter.
f. Remove the 3,000-ohm resistor and insert
g. The voltages measured on the ME-30A/U
it between pins 4 and 8 of the OCTAL tube test
will be equal to the voltages indicated on the
socket.
FILAMENT VOLTS meter 6 percent error at
g. Set the ON-OFF switch to the ON position.
each point.
h. The FIL. CONT. SHORT lamp glows con-
33. Gas Test
tinuously when the SHORT TEST switch is set
(C, fig. 21)
to positions Y and Z.
i. Set the ON-OFF switch to the OFF position.
Caution: Be sure that the power switch is in
j. Remove the 3,000-ohm resistor and insert
the OFF position before performing the gas test.
it between pins 5 and 8 of the OCTAL tube test
a. Set the GRID switch to position 4.
socket.
b. Set the CATHODE switch to position 7.
k. Set the ON-OFF switch to the ON position.
c. Set the FUNCTION switch to position VR.
l. The FIL. CONT. SHORT lamp glows con-
d. Set the GM-SIGNAL RANGE switch to
tinuously when the SHORT TEST switch is set
position A and all other switches and controls
to positions X and Z.
to their neutral or OFF position (vertical posi-
tion for switches, extreme counterclockwise
36. Cathode Bias Resistance Test
position for controls).
(D, fig. 21)
e. Connect the AN/URM-105 between pins 4
Caution: Be sure that the power switch is in
and 7 of the OCTAL tube test socket.
the OFF position before performing the cathode
f. The AN/URM105 indicates a resistance
bias resistance test.
of 180,000 ohms 10 percent error when the
a. Set the CATHODE switch to position 1.
PRESS TO TEST P6 switch is depressed.
b. Connect the AN/URM105 between pin 1
34. leakage Test
of the OCTAL tube test socket and a ground test
point (mounting screw) on the tube tester
a. Set the tube tester up according to the tube
chassis.
test data roll chart, to test tube 6V6.
c. The resistance reading of the AN/URM-
b. Insert the 6V6 tube and perform the inter-
105 is 47, 94, 141, 188, or 288 ohms when the
element leakage (LK) test.
BIAS RANGE switch is set to position A, B, C,
c. Remove the 6V6 tube and insert a 450,000-
D, or E, respectively, 10 percent error at each
ohm resistor between pins 4 and 8 of the OCTAL
point.
tube test socket.
d. Set the SHORT TEST switch to position Y.
37. Filament Continuity Test
e. Set the ON-OFF switch to the ON position.
a. Check a IL4 tube known to have a closed
f. The PLATE meter indicates to the right of
filament.
the 0.5-megohm point.
39
AGO 1428A
