Shure 527C - Manual

Model 527C User Guide

©2005 Shure Incorporated
27

C

2084 (Rev. 5)

Printed in U.S.A.

Transistorized Dynamic Hand-Held Microphone

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
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.

FEATURES

•

Built-in amplifier

•

Frequency response from 300 to 5,000 Hz, tailored for voice

communications

•

Low sensitivity to hum

•

Low susceptibility to radio-frequency interference

•

“Million-Cycle” leaf-type switch stands up under severe oper-

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

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 2.2K

Ω

is necessary.

With a supply voltage of 16 Vdc and a load resistance of 2.2K

Ω

, 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
470

Ω

load.

CABLE-TO-CONNECTOR WIRING

TABLE 1

TYPICAL OPERATING CIRCUIT

FIGURE 1

CAUTION:
To avoid damage to the 527C, observe the following:

•

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).

•

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.

WIRE COLOR

FUNCTION

BLACK

AUDIO GROUND

RED

AUDIO

GREEN

RELAY CIRCUIT

WHITE

AUDIO

OUTPUT

TRANSMIT

RELAY

CIRCUIT

LOAD RESISTANCE

R

L

5 F

RED (+)

AMPLIFIER

CARTRIDGE

MICROPHONE

BLACK (–)
GREEN
WHITE

SWITCH

+ SUPPLY

VOLTAGE

V

S

5