TM-9-2350-273-BD

M48/M60 SERIES TANK, COMBAT FULL-TRACKED 105-MM GUN

TECHNICAL MANUAL; OPERATORS, ORGANIZATIONAL, DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE; BATTLEFIELD DAMAGE ASSESSMENT AND REPAIR

TM-9-2350-273-BD - Page 178 of 288

TM 9-2350-273-BD

COMMUNICATIONS

SYSTEM

11-21. ONE-QUARTER WAVE ANTENNA FIELD EXPEDIENT GROUND PLANE

General Information:

This procedure gives instructions for construction of a one-quarter wave ground plane

antenna which can be used for transmission and reception.

This antenna has the

capability of increasing the range of FM radios.

Limitations:

●

Can only be used on a stationary vehicle and when a tree is available for suspension

of the antenna.

Personnel/Time Required:

●

1 soldier

●

30 minutes

Materials/Tools:

●

Cable, l-roll, telephone, WD-1/TT

●

Insulators (e.g., glass, plastic, leather, nylon, etc.) (Five required)

●

Rope

●

Sticks or branches, 3-foot length, (three required)

Other Options:

●

Repair broken metallic whip antenna. (Refer to para. 11-17.)

●

Field expedient metallic whip antenna. (Refer to para. 11-18.)

●

Field expedient replacement of fiberglass antenna. (Refer to para. 11-20.)

●

For reception only, field expedient auxiliary antenna. (Refer to para. 11-19.)

Procedural Steps:

1.

Determine the length of wire needed for the radiating element of a one-quarter

wave antenna using the following formula:

Length (feet)

= 234 divided by frequency (MEGAHERTZ)

Length (meters)

= 71.37 divided by frequency (MEGAHERTZ)

Example- A radiating element for a frequency of 50 MHZ:

L (feet) =

234 divided by 50 MHZ =4.68 feet

or

L (meters)

= 71.37 divided by 50 MHZ =1.43 meters

11-23