go to the azimuth/elevation heat sink module. From this module, the signals go through the BITE relay and back into azimuth position compensation module (C1) and elevation position compensation module (D1). Modules C1 and D1 output azimuth and elevation BITE position signals to servo BITE (B2). The servo BITE module (B2) outputs a servo control fail signal to the power supply-video converter BITE logic circuit, which is labeled a servo malfunction in figure 6-20. This logic circuit, in turn, outputs a not ready signal to light the NOT READY light on the control box. With the BITE relay de-energized (as shown), an azimuth loop is formed. This loop consists of the azimuth position compensation (C2), azimuth rate compensation (E1 ), a heat sink module and BITE relay, azimuth rate compensation (E2), and azimuth position compensation (C1). Likewise, an elevation loop is formed. This elevation loop consists of elevation position compensation (D2), elevation rate compensation (F1), a heat sink module and BITE relay, elevation rate compensation (F2), and elevation position compensation (D1). This allows the BITE motor drive signals (developed in C2 and D2) to continue around the loop. The BITE motor drive signals are monitored by frequency and amplitude detectors in servo BITE (B2). The inputs to these detectors are the azimuth and elevation BITE position signals from C1 and D1, which represent the signals in the loops. If an error or failure occurs, servo BITE (B2) generates a servo control fail signal. This signal is sent to the power supply-video converter BITE logic, labeled servo malfunction in figure 6-20. From here a control servo fail signal is sent to the control box to light the CONTROL SERVO FAIL light. If no errors or failures are present during the fault isolation test, which takes approximately 10 to 12 seconds, a BITE 1 signal is generated by servo BITE (B1). This signal terminates the fault isolation test and initiates the BITE 1 test. BITE 1 TEST.— When servo BITE (B1) generates a BITE 1 signal, the signal is fed to mode logic (A2). This causes module A2 to energize the BITE relay (via the BITE relay drive line), reconnecting the heat sink module output to the drive motors in the receiver-converter WRA. This also opens up the azimuth and elevation loops. Mode logic (A2) also generates a FWD command signal. This signal is fed to the azimuth position compensation module (C2) and elevation position compensation module (D2). These two modules generate BITE motor drive signals. These signals are fed through the azimuth and elevation rate compensation modules (E1 and F1) to the heat sink module and the now energized BITE relay. This positions the receiver head in the receiver-converter to 0° azimuth and -4° elevation. Position feedback signals from the receiver-converter are fed to the servo BITE (B2) module where they are monitored. If there is an error/failure, a gimbal fail signal is generated and fed to the servo BITE board in the receiver-converter. This action causes the receiver BITE circuit to generate and send a receiver-converter malfunction signal to the control box to light the RCVR CONV FAIL light. If the feedback signals to B2 are correct (for 10 to 12 seconds), a BITE 2 signal is generated by servo BITE (B1). The BITE 2 signal terminates the BITE 1 test and initiates the BITE 2 test. BITE 2 TEST.— When servo BITE (B2) generates a BITE 2 signal, the signal is fed to the mode logic module (A2) to cancel the FWD command signal. The BITE 2 signal is also fed to the azimuth position compensation module (C2) and the elevation position compensation module (D2). The BITE 2 signal causes these modules to develop and send error motor drive signals to the receiver head by way of the same signal path as the BITE 1 signal. These signals drive the receiver head to 130° azimuth and -60° elevation. Feedback signals are monitored by servo BITE (B2). If an error is present, B2 generates a gimbal fail signal to light the RCVR CONV FAIL light on the control box. This fail signal uses the same path as in BITE 1 testing. If the feedback signals are correct, servo BITE (B1) generates a BITE 3 signal. This signal terminates BITE 2 testing and initiates the BITE 3 test. BITE 3 TEST.— When servo BITE (B1) generates a BITE 3 signal, the module B1 also generates a BITE 3 DCI signal (simulated computer data bit). This signal is sent to the decoder storage module. Simultaneously, a BITE 3 signal is sent to mode logic (A2). This module initiates a computer track command signal and sends it to the azimuth position compensation module (C2), the elevation position compensation module (D2), and the D/A converter module. The computer track command signal enables these modules for the computer track mode. The BITE 3 DCI signals from the decoder storage module are processed by the D/A converter. The D/A converter outputs azimuth and elevation rate signals. A circuit in the D/A converter monitors the amplitude and frequency of these rate signals. If the amplitude and frequency are incorrect, the D/A converter generates a DCI fail (either azimuth or elevation) signal to the servo BITE (B2). This module outputs a servo control fail signal, which, in turn, lights the 6-23