Making an RF Transmitter Output Tester.

TM 5-4120-394-BD

SECTION III (Cont)

Field Expedient Test Equipment (Cont):

2. Making an Ohmmeter (continuity tester)

An ohmmeter can be made from a

flashlight bulb, flashlight battery, and

three pieces of wire. When the free

ends of the wires are touched to a

circuit where continuity (or a short)

exists, the bulb will glow. If a two-cell

flashlight bulb is used with only one

battery, the bulb will glow with one-half

its normal brilliance.

3. Making an RF Transmitter Output Tester.

This device is used to determine if the

radio is sending a signal to the

An RF transmitter output tester can be made from a neon light bulb and a piece of CG-1773 RF cable.

Solder the bulb to the cable as shown in the illustration. Connect the cable to the ANT connection on the front of the radio.

When the radio is keyed, the bulb will glow if RF power is present at the antenna connection (this does not verify

transmitter frequency accuracy).

Another way to check for transmitter output is to hold a common (wood) lead pencil tip 1/4-inch to 1/8-inch

from the ANT connection. If RF power is present, a yellowish-white arc will jump from the connector to the pencil tip when

the radio is keyed.

B-4