tile cord which will extend to over 6 feet. The cord
7.2. Purpose and Use
is terminated in a 5-pin connector type U-229/U. A
The H-189/GR is a lightweight handset. It is used
clip on the back of the handset permits it to be at-
with portable and vehicular radio equipment. The
tached to clothing.
earphone portion is thin enough to slip under Com-
bat Helmet M1.
7.5. Connecting and Using H-189/GR
7.3. Technical Characteristics
a. Connecting. Insert Connector U-229/U into
Frequency response . . . . . 300 to 3,500 cps.
the proper receptacle on the equipment and slowly
Weight . . . . . . . . . . . . . . . . . . . . . . . 1 lb, 3 oz.
rotate the connector clockwise with a steady for-
Microphone resistance . . . approximately 3.3 ohms.
ward pressure. When the guide pins of the connec-
tor are in the proper grooves, the connector will
Earphone resistance . . . . Approximately 23 ohms.
move forward and seat itself. Twist the knurled
portion of the connector to the right and pull
sharply to set the connector.
b. Using. Hold the handset so that the earphone
The H-189/GR is a light, watertight, durable hand-
is against the ear and the microphone is approxi-
set. It is 8 inches long, 1-9/16 inches wide, and
mately one-half inch from the lips. The earphone
tapers in thickness from 7/8 inches to 3/8 inches.
can be slipped under Combat Helmet M1. To talk,
The microphone and earphone elements are plug-in
depress the switch bar; to listen, release the switch
closed in the handset, is a double-pole, single-throw
c. Disconnecting. To disconnect the H-189/GR
bar-activated type with normally open contacts.
from the equipment, slowly rotate Connector U-
When the bar is depressed, the contacts close in
229/U counterclockwise with a steady forward
sequence; the microphone circuit first, and then the
control circuit. The H-189/GR has a 24-inch retrac-