Model 527C User Guide
CONNECTIONS
A typical external operating circuit is shown in Figure 1. Circuit
parameters such as supply voltage, load, current and sensitivity
may be selected using the curves shown in Figures 3 and 4. If, for
instance, the available supply voltage is 16 Vdc and a current drain
of 4 mA is desired, a load resistance (RL) of 2.2KΩ is necessary.
With a supply voltage of 16 Vdc and a load resistance of 2.2KΩ, the
relative sensitivity is approximately +8 dB, or –3 dB output level ref-
erenced to the specified output level of –11 dB with 10 Vdc and a
470Ω load.
WIRE COLOR
BLACK
FUNCTION
AUDIO GROUND
AUDIO
RED
GREEN
WHITE
RELAY CIRCUIT
Transistorized Dynamic Hand-Held Microphone
CABLE-TO-CONNECTOR WIRING
The Shure Model 527C is a dynamic hand-held communica-
tions microphone for use in a variety of mobile and fixed-station ap-
plications, including police, transportation, amateur radio and
similar applications. The 527C offers extremely low sensitivity to
hum pickup and low susceptibility to radio-frequency interference.
A built-in solid state amplifier permits the use of up to 30 m (100 ft)
of unshielded cable. The modular construction of the 527C allows
the cartridge, switch, and cable to be replaced in a matter of min-
utes, if necessary. The 527C fits naturally and comfortably in the
hand and is not adversely affected by heat or humidity. The
TABLE 1
MICROPHONE
CARTRIDGE
5
F
RED (+)
LOAD RESISTANCE
+
SUPPLY
R
VOLTAGE
L
V
AUDIO
AMPLIFIER
S
OUTPUT
BLACK (–)
GREEN
WHITE
TRANSMIT
RELAY
CIRCUIT
®
ARMO-DUR case is immune to oil, grease, fumes, salt spray,
sun, rust and corrosion, and is outstanding in its ability to withstand
mechanical shocks and vibration.
SWITCH
TYPICAL OPERATING CIRCUIT
FIGURE 1
FEATURES
CAUTION:
To avoid damage to the 527C, observe the following:
• Built-in amplifier
• Frequency response from 300 to 5,000 Hz, tailored for voice
•
Supply voltage (V) must be between 4 and 35 Vdc. Voltages ex-
ceeding 35 Vdc may substantially reduce the life of the micro-
phone. Voltages below 4 Vdc are not sufficient for microphone
amplifier operation (although no damage will occur).
communications
• Low sensitivity to hum
• Low susceptibility to radio-frequency interference
• “Million-Cycle” leaf-type switch stands up under severe oper-
•
•
Do not exceed the maximum allowable current (dissipation lim-
it) for the various combinations of supply voltages and load re-
sistances.
Maintain proper polarity for the red (+) and black (–) leads as
shown in Figure 1.
ating conditions and constant use
®
• High-impact ARMO-DUR case—lighter and stronger than
die-cast metal, comfortable to the touch in hot or cold weather
• Rugged and dependable under all operating conditions
• Long-life neoprene-jacketed coil cord
©2005 Shure Incorporated
Printed in U.S.A.
5
27C2084 (Rev. 5)
|