Tabulated Data

TM-11-5985-355-13

VRC 12 series radios (AN VRC-12 and AN VRC-43

frequency selector switch and two connectors.

through AN V'RC-49 (TM 11-5820-401-12)) and low-

(2) Base assembly consists of a Lexan

powered Radio Sets AN VRC-53, AN VRC 64 AN GRC-

plastic housing, rf coil container, and an rf coil. The rf

125 and AN GRC-160(TM11-5820-498-12). The AS-

coil container is an rf coil cage, and the rf coil assembly

2731 GRC can be installed in jeeps, tanks, and other

is an RG-303 U 50-ohm coaxial cable wrapped around a

armored vehicles and where Antenna AS-1729 VRC

ferrite rod that transfers rf energy to the antenna. To

(TM 11-5985-262-15) has been installed.

minimize antenna current, the susceptance of the rf coil

to ground is changed at different subband frequencies by

1-7. Tabulated Data

a step-action rotary solenoid selector switch.

a. Technical Characteristics.

(3)

The frequency selector assembly

Antenna type ...........................................Whip.

provides required components for each subband to

Frequency range .....................................30 to 80 MHz.

maintain a vswr of 3.5 to 1 or lower. Switching and relay

Power-handling capability ......................70 watts

assembly directs to the desired subband the required

.............................................maximum.

shunt reactors and impedance networks.

Control

Input impedance ......................................50 ohms.

voltages from an associated radio receiver-transmitter

Weight

.............................................10 pounds.

unit (ret unit) positions the rotary solenoid to the correct

b. Component Dimensions. Refer to appendix B

subband, or if desired, a manual selection of the desired

for component National stock numbers (NSN's). Refer

subband can be made using frequency selector switch

to TM 11 -5985-355-24P for parts and NSN's of the

S1.

installation hardware (fig. 1-1).

(4) The spring assembly is mounted on top

Largest Length Weight

of the base assembly, and consists of a spring mount

Item

dia (in) (in)

(lb)

assembly through which an rf cable assembly runs. The

Matching Unit-Base

5.50

16.00 6.5

spring mount provides threaded connection at the top of

MX-9146 GRC

the spring for attaching the AS-2732, GRC. It supports

Antenna Element

1.75

64 25 2.5

the AS-2732'GRC in a vertical position and is flexible

AS-2732 GRC

enough for the AS-2732 GRC to survive high impact

Cable Assembly, Special Pur-1.00

12.00 1.0

blows from obstructions.

pose, Electrical CX-

(5) Mounting hardware includes screws,

13055 GRC

nuts, lockwashers, a gasket, and a bonding jumper

Cable Assembly. special Purpose, Electrical CX-

assembly for installation of the AS-2731 GRC. The

13184 GRC

supplied gasket is placed between the base cover flange

Largest dia (in)

Length (in)

Weight (lb)

of the MX-9146/GRC and the antenna mounting bracket

1.0

18.00 1.0

for preventing water leaks into a ground vehicle,

1-8. Description

especially in tank installations. The bonding jumper is

(fig. 1-1)

connected between one of the posts under the MX-9146

Antenna AS 2731 GRC consists of Matching Unit-Base

GRC and the other end to the vehicle. A lock wire is

MIX-9146 GRC with mounting hardware, Antenna

obtained locally.

Element AS-2732 GRC, and Cable Assembly, Special

c. Cable Assembly, Special Purpose, Electrical

Purpose, Electrical CX-13055 GRC.

CX-13055 GRC. The cable assembly is a short adapter

a. Antenna Element AS-2732GRC. The AS-2732 GRC

cable connected between cable connector of AS-2731

is a 5 ½-foot whip section assembly with a threaded

'GRC and control cable of associated radio (fig. 2-5).

base. It is attached in a vertical position to the top of the

Cable Assembly, Special Purpose, Electrical CX-

cable mount on Matching Unit-Base NMX-9146 GRC,

4722(*)VRC is the control cable used to connect the

extending the transmit-receive range capabilities of the

radio to the MX-9146:GRC. (*) represents all models of

associated radio. To prevent the AS-2732 GRC from

the cable assembly.)

vibrating loose, a lock wire (fig. 2-2) is attached between

d. Cable Assembly, Special Purpose, Electrical

the AS-2732 GRC and the MIX-9146 GRC.

CX-13184/GRC (fig. 1-1). This cable is 18 inches long

b. Matching Unit-Base MX-9146 GRC.

and performs the same function as CX-13055/GRC.

(1)

Matching Unit-Base MX-9146 GRC

CX-13184'GRC is provided in lieu of CX-13055/GRC on

usually is attached on the outside of a wheeled vehicle,

contract DAAB07-76-C-0164 This cable must be

tank or armored personnel carrier. It consists of a spring

installed as part of the AS-2731/GRC

assembly, base assembly, matching unit case, and

mounting hardware. On the bottom of the MX-9146

GRC, three posts provide physical protection for the

1-2