The Shure Model 577B SONOBAR® Microphone is a handheld dynamic microphone designed for communications and paging applications that require highly intelligible, low noise output. It can be used in all types of mobile communications, from amateur radio to helicopter news and traffic reports. It is also suitable for public address and paging systems in noisy areas such as factories, airport terminals, and restaurants.
The 577B represents a significant improvement over most microphones with anti-noise features. Shaped frequency response, directionality, and distant sound discrimination contribute to total noise reduction. The microphone operates on the pressure-gradient principle and has two sound entry ports spaced a small distance apart.
The modular design of the 577B greatly facilitates field servicing. The cartridge, switch, and cable can be replaced in a matter of minutes, if necessary.
The 577B is built to withstand mechanical shocks, vibration, high temperatures, and humidity. The exclusive ARMO-DUR® case is impervious to oil, grease, fumes, salt spray, sun, and corrosion. he “Million-Cycle” press-to-talk switch ensures years of reliable service.
A mounting bracket is supplied to provide convenient hang-up when the microphone is not in use.
For optimum performance and maximum rejection of background noise, place your upper lip against the lip guard, approximately 25 mm (1 in.) from the grille. Hold down the push-to-talk button while talking normally.
The 577B is a balanced-line, low-impedance dynamic microphone. It is designed for direct connection to low-impedance microphone inputs and/or installations where long cable lengths are needed. It includes a four-conductor (two conductors shielded) coiled-cord cable and a double-pole, single-throw, leaf-type switch. The WHITE and GREEN leads are the “hot” audio conductors; the shield is connected to microphone circuit ground. The RED and BLACK leads control the switch circuit. The microphone circuit is open when the switch is open, but can be easily modified for normally shorted operation. Refer to Figure 1.
FIGURE 1: INTERNAL CONNECTIONS
| INPUT TYPE | WIRE COLOR | FUNCTION | XLR CONNECTOR | ¼ IN. PHONE PLUG |
| BALANCED | WHITE | AUDIO+ | PIN 2 | TIP |
| GREEN | AUDIO- | PIN 3 | RING | |
| SHIELD | CHASSIS GROUND | PIN 1 | SLEEVE | |
| UNBALANCED | WHITE | AUDIO | -- | TIP |
| GREEN | AUDIO GROUND | -- | SLEEVE | |
| SHIELD | CHASSIS GROUND | -- | SLEEVE |
To modify the microphone circuit for normally shorted operation, proceed as follows:
Dynamic (moving coil)
100 to 5,000 Hz
at 1kHz
EIA rated at 150 Ω (175 Ω actual)
at 1kHz, open circuit voltage
-66.0 dBV/Pa (0.5 mV)[1]
Equivalent to 32 dB SPL in 1 millioersted field
-40° to 74° C (-40° to 165° F)
Double-pole, single-throw, leaf-type, Push-to-Talk
Non-detachable, 1.8 m (6 ft), neoprene-jacketed coil cord, four-conductor (two conductors shielded)
Two-tone gray, high impact ARMO-DUR®
330 g (11.6 oz.)
FIGURE 2: TYPICAL FREQUENCY RESPONSE
FIGURE 3: OVERALL DIMENSIONS
This product meets the Essential Requirements of all relevant European directives and is eligible for CE marking.
The CE Declaration of Conformity can be obtained from: www.shure.com/europe/compliance
Authorized European representative:
Shure Europe GmbH
Headquarters Europe, Middle East & Africa
Department: EMEA Approval
Jakob-Dieffenbacher-Str. 12
75031 Eppingen, Germany
Phone: +49-7262-92 49 0
Fax: +49-7262-92 49 11 4
Email: info@shure.de
Mounting Bracket (3 per kit)
| Cartridge for 577B | R98B |
| Cable for 577B | C117 |
| Switch for 577B | RK338S |
For additional service or parts information, please contact Shure's Service department. Outside the United States, please contact your authorized Shure Service Center.
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