Test Equipment and Tools Required - TM-11-6625-667-450088

TM 11-6625-667-45/NAVAlR 16-30APM123-2/T0 33A1-3-367-22

(5) Extender board. Measurements to be

the open circuit voltage across the

made at points other than at the test jacks

ohmmeter test leads. Do not use the

require the use of an extender board (fig. 3-6).

ohmmeter if the open circuit voltage

The extender board is designed so that 11 con-

exceeds 1.5 volt. Also, since the RX1

nections are symmetrically placed on each side of

range normally connect the ohmmeter

center. Because of the symmetrical design, in-

internal battery directly across the test

sertion of the extender board right side up or

leads, the comparatively high current

(50 ma or more may damage the

wrong side up will not mechanically or electrically

affect the circuit. However, plug in boards in

transistor under test. As a general rule,

serted in the extender board must be inserted

the RX1 range of any ohmmeter should

exactly the same as originally positioned in the

not be used when testing low powered

equipment.

transistors.

(6) Resistor, capacitor, and diode color code

(3) Waveforms. Signals associated with

diagrams. Color code diagrams for resistors,

digitial circuits are illustrated with waveforms.

capacitors, and diodes (fig. 8-0.1 and 8-0.2)

Unless otherwise specified, pulse duration is a

provide pertinent resistance, voltage rating, and

secondary consideration. I m p o r t a n t pulse

tolerance information.

durations are specified as nominal values when

applicable. Test Point pulse amplitudes are not

CAUTION 1

shown, since they all range between 7 and 12

Make sure that no metal objects

volts. Waveforms shown for the transmitter

(screwdriver, pliers, etc.) come in

output specify all characteristics of the pulses

contact with the printed circuit board

excepts the levels, which are determined by

while power is applied. A short circuit

power measurements of the transmitter output.

of the wiring could damage the solid

state circuit elements mounted on the

NOTE

board.

When pulse duration is specified, it is

measured between the 50 percent

points of the waveform. Pulse spacing

CAUTION 2

is measured between the 50 percent

Be certain both the extender board and

points of the leading edges of the

plug in board are properly installed in

specified pulses.

their respective sockets.

(4) Test points. All electrical subassemblies

3-14. Test Equipment and Tools Required

of the test set are equipped with test jacks to

facilitate connection of test equipment (para

The following chart lists the test equipment (a

3-1b). These test jacks should be used whenever

below) for general support maintenance of Test

possible to avoid needless dissembly of the

Set, Transponder AN/APM-123V(V)1,2,3. The

equipment. The test points are shown On the

associated technical manuals are also listed.

schematic diagrams. Figure 8-36 illustrates the

Tools are listed in b below.

waveforms for certain test points. Physical

CAUTION 1

location of the test points is shown in figure 3-6.

Make test equipment connections

Test point (TP) numbers are color coded and can

carefully to avoid short circuits that

be identified by the standard RETMA color code

c a n be caused by exposed test

as indicated in the chart below:

equipment connections. Tape or sleeve

Test point

test probes or clips, as necessary; leave

Test point color

number

only sufficient metal exposed to make

Brown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

contact to the circuit under test.

Rd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Oragne . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

CAUTION 2

Yellow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

The power must be turned off when a

Green . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

circuit card is to be removed or in-

Blue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

serted in the extender card. The card

Violet . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . .7

Gray . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

m u s t be inserted in the extender

White . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Change 5 3-43