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
cable connected between cable connector of AS-2731
is a 5 -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
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