Section V. FUNCTIONING OF WAVEGUIDE SWITCH POSITION INDICATOR CIRCUITS

TM 11-5820-695-35

Section V. FUNCTIONING OF WAVEGUIDE SWITCH POSITION INDICATOR CIRCUITS

2-80.

AN/GRC-144(V)3 and AN/GRC-144(V)4

b. AN/GRC-144(V)4 C-band/K-band Configuration

Waveguide Switch Position Indications

In this configuration two waveguide switches are used.

The position indication signals are routed to the

The waveguide switches that route the RF energy

FREQUENCY BAND IN USE (GHZ) indicator at

between the radio set and the antenna have auxiliary dc

STATUS PANEL 3A8 in Unit 3 and to relay assembly

switches that are used to provide signals for remote

1A15A18 in the transmitter. Figure 2-30 is a simplified

indication of the RF switch position. There are three

schematic diagram of the connections. The waveguide

configurations to be considered; they are explained in a

switches are shown in the figure in the C-band position.

In this position, the +28 Vdc source in the transmitter

through c below.

supplies the voltage (at 3A7J2-E and -H) to light the

indicator at STATUS PANEL 3A8. The +28 Vdc at

a. AN/GRC-144(V)3, Hi-Cap LOS Configuration.

3A7J2-H is also connected to 3A7J2-W and through the

In this configuration, only one waveguide switch is used;

waveguide switch to 1A1534-g and 1A15A18K4. For K-

its positions are antenna and dummy load. Auxiliary

band position, the +28 Vdc is connected through the

switch terminals A through F are used to route position-

waveguide switches to 3A7J2-F and -G and to STATUS

indication signals to connector P11 (mounted in the

PANEL 3A8. It is also connected from 3A7J2-F to

shelter) and to relay assembly 1A15A18 in the

3A7J2-V and applied through the waveguide switch to

transmitter. Figure 2-29 is a simplified schematic

1A15J4-g and relay 1A15A18K4. Note that for either C-

diagram of the connections. The waveguide switch is

band or K-band position of the waveguide switches, +28

shown in the figure in the dummy load position. In this

Vdc is routed to STATUS PANEL 3A8 and to relay

position, P11-J and -L are connected together through

1A15A18K4 through both transmit and receive

switch terminals E and F and P11-K is open circuit. The

waveguide switches. Thus, unless both waveguide

connection from terminal A of the waveguide switch to

switches are in the same band position, the signal paths

1A15J4-g is open circuit. For dummy load position relay

described above are incomplete. The chart below lists

1A15A18K4 is not energized (para 2-64.1). For the

the indications at STATUS PANEL 3A8 for each

antenna position of the waveguide switch, terminal B is

condition described; it also shows the corresponding

connected to terminals A and D and terminals E and F

status of relay 1A15A18K4.

Operation of relay

are open circuit. P11-K is then connected to +28 Vdc

assembly 1A15A18 is described in paragraph 2-64.1.

and P11-J and -L are open circuit. The +28 Vdc at

The bottom section of the chart lists STATUS PANEL

terminal B is connected through terminal A and lA15J4-

indications for the K-band only configuration for

gto relay 1A15A18K4. For the antenna position, relay

reference in c below.

1A15A18K4 is energized (para 2-64.1).

Change 6 2-121