Shure LMP1A User Guide

Model LMP1A User Guide

GENERAL

The Shure Model LMP1A is a multi-purpose level-matching preamplifier designed for two-way radio communication applications. The LMP1A allows Shure dynamic communication microphones to be used with many popular two-way radios and remote control devices.

The LMP1A can operate on biased audio supplied by the radio or 12 Vdc provided by an external power supply. Its output can be adjusted to match the inputs of many two-way radios.

FEATURES:

•Compact design

•Input and output terminals for easy connection to microphones and radios

•Adjustable gain

•Uses either biased audio or external 12 Vdc power

•Heavy duty die cast aluminum case

INSTALLATION

CONNECTING THE LMP1A TO BIASED AUDIO RADIOS

1.Remove the screws that secure the LMP1A cover to the chassis and lift the cover away.

2.Refer to Figure 1 and connect a dynamic microphone, such as a Shure Model 515, to LMP1A input terminals as follows:

•White mic lead to LMP1A Audio In

•Green mic Lead to LMP1A Ground

•Shield to LMP1A Ground

3.Connect LMP1A output terminals to the radio input as follows:

•LMP1A Audio Out to Radio Mic High Input

•LMP1A Ground to Radio Microphone Low Input or Ground.

4.Reinstall the LMP1A top cover.

©2003 Shure Incorporated 27D3050 (Rev. 4)

CONNECTING THE LMP1A TO NON-BIASED AUDIO RADIOS

1.Remove the screws that secure the LMP1A cover to the chassis and lift the cover away.

2.Refer to Figure 2 and connect a dynamic micorphone, such as a Shure Model 515, to the LMP1A input terminal as follows:

•White mic lead to LMP1A Audio In

•Green mic lead to LMP1A Ground

•Shield to LMP1A Ground

3.Connect the LMP1A output terminal to the radio input as follows:

•LMP1A Audio Out to Radio Microphone High Input

•LMP1A Ground to Radio Microphone Low Input or Ground

4.Connect the LMP1A external dc bias terminal to the positive terminal of the radio power supply.

5.Connect the LMP1A ground terminal to the negative terminal of the radio power supply.

6.Reinstall the LMP1A top cover.

			INPUT
	GND	SHIELD
	GND	GREEN	FROM DYNAMIC MIC
OUTPUT	AUDIO IN	WHITE
TO RADIO MIC	MIC HI
IN	MIC LO	EXT DC BIAS
		AUDIO OUT
		GND

LMP1A CONNECTIONS FOR BIASED AUDIO RADIOS

FIGURE 1

			INPUT
	GND	SHIELD
	GND	GREEN	FROM DYNAMIC MIC
OUTPUT	AUDIO IN	WHITE
	+ PWR
12 VDC POWER SUPPLY	MIC HI
TO RADIO MIC	– PWR	EXT DC BIAS
IN
	MIC LO
		AUDIO OUT
		GND

LMP1A CONNECTIONS FOR NON-BIASED AUDIO RADIOS

FIGURE 2

Printed in U.S.A.

LMP1A GAIN ADJUSTMENT

1.Remove the screws that secure the LMP1A cover to the chassis and lift the cover away.

2.Refer to Figure 3. Using a screwdriver, rotate potentiometer R5 clockwise to increase gain. The LMP1A provides 20 dB of gain when potentiometer R5 is in the maximum (full clockwise) position. To decrease gain, rotate potentiometer R5 counterclockwise.

ADJUSTING LMP1A GAIN

FIGURE 3

SPECIFICATIONS

Open Circuitry Gain

20 dB at 1 kHz, with potentiometer R5 set to maximum

Power Requirements

3.5 to 20 Vdc (Bias voltage supplied by radio);

12 Vdc provided by external power supply

Current Drain

0.7 mA at 12 Vdc

Case

Die-cast aluminum construction

Dimensions

63.75 mm x 57.66 mm x 35.05 mm (2.51 in. x 2.27 in. x 1.38 in.)

Net Weight

146 grams (5.15 oz)

Certification

Eligible to bear CE Marking. Conforms to European EMC Directive 89/336/EEC. Meets applicable tests and performance criteria in European Standard EN55103 (1996) parts 1 and 2, for residential (E1) and light industrial (E2) environments.

FROM MICROPHONE

TO RADIOS

LMP1A SCHEMATIC DIAGRAM

FIGURE 4

SHURE Incorporated Web Address: http://www.shure.com 5800 W. Touhy Avenue, Niles, IL 60714-4608, U.S.A. Phone: [phone] Fax: [phone]

In Europe, Phone: [phone] Fax: [phone] In Asia, Phone: [phone] Fax: [phone] Elsewhere, Phone: [phone] Fax: [phone]

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