LBI-39181
3
GENERAL
Model 344A4611 is a hand-held, amplified, condenser
DTMF communications microphone with an illuminated
keypad. The microphone is ideal for upgrading existing two-
way radios for use with advanced telephone interconnect
systems or for new installations. It is designed for rugged
and reliable operation in any mobile communications
application. The microphone has an omni-directional pickup
pattern and provides extremely clear transmission, even in
noisy environments. In addition to its clear, crisp, natural
voice response, the microphone has extremely low
sensitivity to hum pickup and low susceptibility to radio
frequency interference.
For installations where transmitter input gain requires
sensitivity modification, the microphone has convenient,
externally accessible screwdriver controls for independent
adjustment of both microphone and DTMF levels. This
eliminates the problem of fixed audio levels and the
necessity for disassembling the microphone for adjustments.
Restricting control access also prevents accidental changes
common to external controls.
The microphone is designed for use with most currently
available mobile two-way radio transceivers. For installation
convenience, all microphone and signalling functions,
including keypad illumination, are powered directly from the
microphone input circuit of most transmitters, minimizing
the need for equipment modification. The microphone is
compatible with a choice of five-conductor, pre-wired, coil-
cord MODULINK
®
cables, each of which has a telephone-
type modular plug on the microphone end, and a choice of
popular transmitter input connectors on the other. The cables
are instantly changed or replaced without soldering.
The microphone features attractive, contemporary
styling, designed to blend with most radio designs and
vehicle interiors. The microphone is ergonomically
designed; it fits naturally and comfortably in the hand and is
not affected by heat or humidity. The rugged ARMO-DUR
®
case is immune to oil, grease, most fumes and solvents, salt
spray, sun, rust and corrosion. It is outstanding in its ability
to withstand mechanical shocks and vibration. The Million-
Cycle PIus™ leaf-type switch is a double-pole, single-throw
type, designed to resist the effects of severe operating
conditions and constant usage. It has nickel-silver blades,
and its contacts are palladium-alloyed for reliable,
oxidation-free operation.
The microphone’s keypad is made of tough silicone
rubber, with durable printed characters that will last the life
of the microphone. The keypad is backlit by red LEDs,
easily visible during night operation and minimizing eye
readjustment for night vision.
The microphone is supplied with a small screwdriver
for adjusting the microphone amplifier gain and DTMF
level, and for releasing the modular-plug microphone cable
from the microphone.
FEATURES
•
Top-Talk Sound Channels™ for clear voice input, easy
handling
•
Built-in transistor amplifier (powered by carbon-
microphone- type circuit)
•
Frequency response from 200 to 4,000 Hz, tailored for
voice communications
•
Illuminated keypad with positive tactile feel and audible
confirmation tones
•
Auto push-to-talk (APTT) automatically keys trans-
mitter when keypad is depressed
•
Convenient external microphone gain adjustment
accommodates most input circuits
•
Simple, easy-to-use continuous-tone dialing
•
Externally accessible DTMF level adjustment,
independent of microphone gain setting
•
Modular-plug coil-cord-easily attached and removed
•
Low susceptibility to radio frequency interference
•
Low sensitivity to hum pickup
•
Rugged Million-Cycle Plus leaf-type switch stands up
under severe environments and constant use
•
High-impact ARMO-DUR case - stronger and lighter
than diecast metal, comfortable to the touch in hot or
cold weather
•
Rugged and dependable under all operating conditions
•
Hang-up button connection available for microphone
hang-up sensing (mounting bracket must be grounded)
