Figure 2-4. Train plus I/P pulse timing diagram.

11-6695-667-45/NAVSHlPS

0969-249-8010/NAVAIR

16-30APM123-2/TO

33A1-3-367-22

Figure 2-4. Train plus I/P pulse timing diagram.

RF pulses are routed by the self-test relay to the

error detector, bypassing preselect or A15Z1. The

detected video is amplified by the video amplifier

as during normal tests. When the test set RF level

is normal, the pulse are gated and shaped by

video shaper DSS1. These pulses are compared

at the error detector with those from the encoder.

An accept indication is provided when all appli-

cable circuits are performing correctly. Receiver

gate 2 is disabled when encode enable IFF1 is re-

set by the DE (P3) pulse (para 2-2d).

2-8. Frequency-Power Test

(fig. 8-1)

A frequency-power test can be performed to deter-

mine whether the transponder transmitter or its

2-7. Self-Test Operation

associated coder is causing a reject. When this test

is performed, errors caused pulse information are

inhibited at the error detector. At least one pulse

During self-test, the encoder, modulator and trans-

must be received to determine the transponder

mitter, receiver section, and reply evaluator are

transmitter frequency and power level. If a pulse

tested. The receiver gate is enabled by encode en-

is not received, a reject will occur, indicating that

able IFF1 during self-test. The transmitter section

Change 1

2-9