Table 3-4. Motor Control CCA A2 Test Point Signals

TM 32-5865-216-24&P

Motor Control CCA A2 Test Point Signals

Table 3-4.

Signal

Test point

A1 high test

TP1

TP2

A low test

TP3

TP4

B low test

TP5

TP6

TP7

B1 high test

TP8

A2 high test

TP9

TP10

TP11

TP12

MOTOR FLYBACK

TP13

TP14

B2 high test

TP15

As shown in figure FO-4, input A1 is applied through driver Q5 to

voltage regulator U1. Voltage regulator U1 provides a constant

current source to current amplifiers Q6 and Q1. The resulting A1

high output is routed to the windings of stepper motor M1 and to

extender CCA A5. Diode CR2 prevents excessive current surges to the

motor windings and provides a MOTOR FLYBACK output to extender CCA

AS.

3-5.4 RF Switch Assembly. Refer to figure 3-5. The RF switch

assembly contains four rotary switch wafers and eight RF CCAS.

Stepper motor M1 operates the switch wafers to select one of 20 tuned

circuits through the CCAs. As shown in figure FO-5, RF relays K1 and

K2 receive TX/RX inputs and control the RF path through the RF switch

assembly. For the transmit mode, relays K1 and K2 operate. Relay K1

applies the RF input from connector J2 to the selected tuned circuit.

Relay K2 applies the tuned circuit output through connector J1 to the

external antenna. For the receive mode, relays K1 and K2 are de-

energized and the RF switch assembly is bypassed.

Refer to figure FO-1. The feedback

3-5.5 Feedback Switch CCA S4.

switch CCA receives Band 0 through Band 24 signals from control logic

CCA A3 that specifies the transmit mode operating frequency. The

feedback switch CCA is operated by stepper motor M1, and provides an

SW FDBK output to control logic CCA A3 when the stepper motor reaches

the proper position.

STATUS CIRCUIT.

3-6.

The tunable coupler status circuit receives antenna-deployed

switch and DF input signals at connector pins J3-A through J3-D. The

signals are combined with status signals from the tunable coupler

CCAS and applied to external equipment in the system.

3-10