Vehicular Installation

TM 11-5820-509-12

Antenna Installation. Two antennas are

(e) if convenient, the long-wire antenna may also

furnished with the radio set; Antenna AS-1320/ PRC-47

be clamped to the exposed connector of one of the lower

(whip) and Antenna AS-1321 /PRC-47 (long wire). The

sections of the AS-1320/PRC-47 instead of attaching the

long-wire antenna is normally more efficient for

adapter directly to the ANTENNA connector.

transmission in the 2- to 9-MHz range; the whip antenna

(3) Vehicle and fixed station. To set up either a

is most efficient in the 9.000- to 11.999-MHz range.

vehicle or fixed station antenna, use the following

procedure:

(a) Remove the antenna and adapter. Connect the

CAUTION

antenna adapter to the ANTENNA connector on the

When the receiver-transmitter is

receiver-transmitter control panel.

mounted on a vehicle, do not use the

whip antenna. Connect the receiver'

CAUTION

transmitter to the vehicle antenna,

since

the

ANTENNA

terminal

The overall length of the lead-in and

insulator on the front panel can be

the antenna should not exceed the

broken if an obstruction strikes the

lengths in paragraph 3-11c for the

whip antenna while the vehicle is in

operating frequency.

motion.

(c) Connect the antenna lead wire to the vehicle or

(1) Antenna AS-1320/PRC47. Install the whip

fixed station antenna.

antenna as follows:

c. Connecting Primary Power. Installation of each of

(a) Remove antenna elements from antenna case

the three power cables for the applicable configuration is

(fig. 2-2).

described below:

(b) Assemble the antenna before attaching it to the

(1) Portable. During portable operation, the primary

Receiver-transmitter Begin assembly from the large-

power source is the battery. For this configuration, install

diameter diameter threaded stud and work toward the tip

Adapter, Battery Terminal MX-4430/PRC-47 on top of

section (fig. 1-2).

the battery. Note that the adapter is keyed for one-way

installation only. Place the connector portion of the

adapter on the same side as the + and - stampings on the

CAUTION

battery. Attach Cable Assembly, Power Electrical CX-

Tighten the mast sections with the

8395/PRC-47 to the connector on top of the adapter before

fingers only; the use of pliers or other

connecting the opposite end to the POWER connector on

gripping tools can damage the mast

the RT-671/PRC47 front panel (fig. 3-1). Proceed to

sections.

paragraph 2-9a.

(2) Vehicle. When the primary power source is a dc

(c) Attach the threaded stud section to the

generator, be sure that the instructions in paragraph 2-8

ANTENNA connection on the front of the receiver-

have been implemented. Connect Cable Assembly, Power

transmitter (fig. 3-1).

Electrical CX-8394/ PRC-47 to the source and then to the

(2) Antenna AS-1321/PRC -47. Install the long-wire

POWER connector on the RT-671/PRC-47 front panel

antenna as follows:

(fig. 3-1). Proceed to paragraph 2-9c.

(a) Remove the antenna from the case (fig.2-2).

(3) Fixed station. When 115-volt, 400-Hz, single-

(b) Connect the end adapter to the ANTENNA

phase power is used for the radio set, use Cable Assembly,

connection on the front of the receiver transmitter

Power Electrical CX-8393/ PRC-47 to interconnect the

(c) Set up the long-wire antenna on masts or attach

powerlines with the RT-671/PRC-47. Proceed to

it to a tree or building. Use insulation to prevent

paragraph 2-9 c.

grounding.

NOTE

2-8. Vehicular Installation

The antenna should be set up as high as

When the receiver-transmitter is used in vehicles, a

possible for efficient operation.

special installation kit (which includes mounting

facilities) must be procured. The kit (Installation Kit,

(d) Use the jumpers to select the correct antenna

Electronics Equipment MK-1519/PRC-47) is listed in SB

length for the operating frequency: 45 feet for 2 to 5 MHz,

11-131.

25 feet for 2 to 9 MHz, and 15 feet for 2 to 12 MHz.

2-5