INSTRUCTION MANUAL
TOA WIRELESS MICROPHONE model WM-320
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GENERAL DESCRIPTION
The TOA WM-320 is a crystal controlled lavalier-pocket type wireless microphone
designed for operation on a specific frequency from 30MHz to 50MHz.
FEATURES
1. Weighing only 106g, the high-performance transmitter is small enough to fit into a
pocket or clip on to a belt, offering complete freedom of movement. The lavalier
microphone permits its user to speak without paying much attention to the
microphone.
2. The transmitter can accept almost any microphones because of its input sensitivity
adjustment control and a detachable connector supplied with 4.5V phantom power.
3. Three (3) "AAA" size alkaline batteries power the WM-320 continuously for 30 hours.
4. Adoption of crystal controlled direct frequency modulation system keeps the oscil-
lation frequency stable against the change of ambient temperature or voltage
fluctuation.
5. Dynamic range can be greatly increased, without incorporating compressor and
expander, for the pickup of audio signals from a quiet whisper to a full "lung
power" without overmodulation and distortion. Its unique circuit design also
assures the excellent signal-to-noise ratio.
6. Two (2) LED's are provided for easy-to-see monitoring of the battery consumption.
7. A built-in AGC circuit acts only for excessive input, suppressing a distortion
spontaneously. The AGC does not act for normal input, enabling the WM-320 to
9. Switching noise produced when turning switch on and off is extremely low, virtually
raising no problem for practical use.
FREQUENCY RESPONSE CURVE
The frequency response has been measured by using a microphone capsule, originally
included in the WM-320 package, with the WT-720 receiver, and also by providing a
sinewave of 94dB SPL from a point 50 cm distant from the microphone head.
provide the same performance as that of the "wired" microphone.
8. The transmitter is provided with a STAND-BY switch to silence the receiver while
the transmitter power switch is OFF. The STAND-BY switch is independently mounted
inside the transmitter lest it is accidentally turned off during use.
