CONTROL CIRCUIT.

TM 32-5865-216-24&P

Motor control CCA A2

Feedback switch CCA S4

RF monitor CCA A6

Power supply CCA A1

Extender CCA A5

3-5.

CONTROL CIRCUIT.

The tunable coupler receives 16-bit, Manchestercoded command

words as serial data input at connector pins J4C and J4D.

The

control circuit decodes each command word to select the transmit or

receive operating mode and tune RF switch assembly S2 to a specified

100-kHz bandwidth. Table 3-1 lists the function of each bit in the

command word.

3-5.1 Decoder CCA A4. Refer to figure 32. The decoder CCA control

circuit converts the command word input into

subband, and data

strobe outputs to control logic CCA A3 and RF relays K1 and K2.

Table

3-2 lists the control signal accessed from the decoder CCA test

points.

As shown in figure FO-2, the digital input passes through

line receiver U18A and parity flipflop U6A to command word detector

and decoder U1 through U5 and U8 through U12.

Three consecutive high

bits indicate a command word follows and provide synchronization data

to clock generator U14. The l-MHz CLK, and RESET outputs of multi-

vibrators U14A and U14B clock the command word into parity flipflop

and shift registers U1 and U2.

If parity is correct (even), the Q

output of U6 clocks the command word into flipflops U8 through U10.

The Q output of U6 also passes to the status circuit (U7) and control

logic CCA A3 as the parity and data strobe signals, respectively.

Flipflops U8 through U10 convert the 16bit command word into 12 fre

quency bits and (DBO through B11) and

signal.

Switch

position

decoder U15 and U16 converts the DB0 through DB11 signals into

Table 31.

Command Word Bit Functions

Bit

Function

Frequency 100 kHz BCD 1

Frequency 100 kHz BCD 2

Frequency 100 kHz BCD 4

Frequency 100 kHz BCD 8

Not used

Parity (even for 16 bits)

Not used

Transmit/Receive (1=TX, 0=RX)

Frequency 1 MHz BCD 1

Frequency 1 MHz BCD 2

Frequency 1 MHz BCD 4

Frequency 1 MHz BCD 8

Frequency 10 MHz BCD 1

Frequency 10 MHz BCD 2

Frequency 10 MHz BCD 4

Frequency 10 MHz BCD 8

3-3