Hickok 539C - Rectifier and Special Tube Tests; Rectifier Tube Testing

The indicating meter will register the tube's value in eight ranges:
A. 60, 000 f-lmho at .25 Volt signal.
B. 30, 000 f-lmho at .25 Volt signal.
C. 15, 000 f-lmho at .25 Volt signal.
D. 6, 000 IJ.mho at .5 Volt signal.
E. 3,000 j1.ffiho at 2.5 Volt signal.
F. 600 IJ.mho at 1. Volt signal.
G. Rectifiers and Diodes, no signal.
H. Voltage Regulator tubes.
The 600 micromho range was designed especially to test subminiature tubes. Low
plate and screen volts are automatically applied when FUNCTION switch is set on posi-
tion F.
The FUNCTION switch automatically changes the signal volts when the appropriate
setting is made.
The chart setting for the tube to be tested will indicate where the FUNCTION switch
should
be set, such as A, B, C, D, E, F, G or H, in the column preceding Micromhos.
The Micromho values printed on the data roll are minimum values. Good tubes will
read above these values.
In the column headed BIAS VOLTS is listed the exact voltage to which the BIAS VOLTS
meter is to be set when testing a tube. Make final bias adjustment after the P4 button is
pressed.
Certain pemode tubes, such as the 3A4, are tested with reduced screen voltage. This
is accomplished by holding down PI and pressing P4. Specific instructions are printed in
the NOTATIONS column for each tube requiring reduced screen voltage.
10.
Rectifier Test. The push switches PI, P2 and P3 are used to test various types
of rectifier elements.
a. The push switch PI is used when testing detector diodes~ It applies a low
voltage which will not
injure the delicate cathode. Good diodes will cause
the meter pointer to read above mark, RECTIFIERS and DIODES O. K.
b. Push switch P2 is used when testing cold cathode rectifiers such as the OZ4.
This applies a voltage sufficiently high to ionize the tube and start conduc-
tion. ,.,. Good tubes will read above the mark, RECTIFIERS and DIODES O. K.
c. Push switch P3 is used when testing ordinary rectifier tubes such as the
SY3. This switch applies a medium voltage which is best adapted to reveal
defects in this type of tube. Goad tubes will read above the mark, RECTI-
FIERs and DIODES O. K.
In the chart column headed SHUNT are listed the numbers to which the SHUNT dial
is to be set when testing Rectifiers and Diodes.
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