Table 2-1. Operator's Controls

TM 11-6625-539-14-4

Table 2-1. Operator's Controls

NOTE

This table covers only items used by the operator; items used by higher category maintenance personnel are covered

in instructions for the appropriate maintenance category.

Function

Control, indicator, or connector

METER ZERO (variable resistor) ______ Adjusts electronic zero of meter.

Meter zero adjusting screw -------------- Adjusts mechanical zero of meter.

Meter __________________________________ Indicates BETA, GM, OHMS, ICES ICO, or IR, condition of diode, and battery status,

depending upon setting of test set controls.

ICES ZERO/OHMS ADJ COARSE ________ Provides a coarse adjustment of the internal bridge circuits to zero meter during

ICES and OHMS functions.

ICES ZERO/OHMS ADJ FINE ------------ Same as above, except provides fine adjustment.

ICES ZERO READ (momentary toggle ZERO position is used to make zero adjustment during- ICES function. READ

switch).

position is used to determine ICES. of device under test.

RANGE (3-position rotary selector Selects a reading range which is compatible with meter deflection.

switch).

X 0.1 position requires the meter reading to be multiplied by 0.1.

X 1.0 position permits meter reading to be used as read.

X 10

position requires that meter reading be multiplied by 10.

FUNCTION (6-position rotary selector Selects the test set function as follows:

switch).

BETA position causes the meter to indicate beta during testing of hi-polar

transistors.

OHMS position causes the meter to indicate the resistance of the circuit

selected by the POLARITY switch.

FET

position causes the meter to indicate transconductance during testing

of field effect transistors.

ICES

position causes meter to indicate leakage during in-circuit testing of

hi-polar transistors or diodes.

position causes meter to indicate leakage during out-of-circuit testing

ICO,IR

of hi-polar transistors and diodes.

DIODE lN/CKT position causes meter to indicate qualitatively the condition

of diode during in-circuit test.

POLARITY (6-position rotary switch) ____ Selects the polarity required for the device under test or selects the portion of the

circuit for which resistance check is to be made as follows:

NPN position is used during testing of NPN hi-polar transistors. Also used

for testing N-channel field effect transistor (FET) devices.

OFF

position is used when the test set is idle. This position should always

be selected when the equipment is not in use.

PNP position is used during testing of PNP hi-polar transistors and for

checking diode leakage. Also used for testing P-channel FET devices.

E-B

position is used to check parallel resistance across EB circuit of

equipment under test prior to in-circuit testing of devices.

C-B

position is used to check parallel resistance across CB circuit of

equipment under test prior to in-circuit testing of devices.

E-C

position is used to check parallel resistance across E-C circuit of

equipment under test, prior to in-circuit testing of devices.

Remote test jacks _______________________ Provide connection of leads for in-circuit testing of devices or where panel-mounted

socket cannot be used. Jacks are identified as follows:

E, S

(yellow) jack provides a connection for the yellow lead that connects

the E (emitter) or S (source) terminal to the test set.

B, G

(black) jack provides a connection for the black lead that connects the

B (base) or G (gate) terminal to the test set.

C, D

(red) jack provides a connection for the red lead that connects the C

(collector) or D (drain) terminal to the test set.

Transistor socket ------------------------ Provides a connection for out-of-circuit testing of small devices with suitable base

terminals.

BAT CHK (momentary toggle switch) - - -

When operated and held in the direction of the arrow, it causes the meter to

indicate the condition of the batteries. Meter pointer must register and remain

in BAT CHK area when switch is held.

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