Shure manual Models 440SL, FIG. a

2 2 2 HARTREY AYE .EVANSTON I L L . CABLE SHUREMICRO

EVANSTON PHONE DA 8 9 0 0 0 .CHICAGO PHONE SH 3 1600

DATA SHEET

Models

440 and 440SL

General: Model 440 and Model 440SL microphones are pressure operated units using the balanced armature controlled magnetic principle and especially designed to have high intelligibility for radio communications and are especially designed for the narrow audio frequency range required for single side band transmission. The microphones have high output level, smooth response, and a semi-directional pickup characteristic.

The Model 440SL i s an integral assembly of a micro- phone, a grip-to-talk, slide-to-lock switch (see operation) and a desk stand. The grip-to-talk switch is similar t o the Shure A88A, having the same long-life features t o with- stand the most severe field requirements of paging and dispatching systems. The switch has a large comfortable grip bar which minimizes hand and finger fatigue. After the bar i s pressed, a positive downward pressure on the grip bar locks the switch. The switch cannot be acci- dently locked, and the unit can be picked up without actuating the switch.

The microphone case, switch case, and the stand are of die cast metal and are streamlined for improved acoustical performance and modern appearance.

Applications: The Model 440 and the Model 440SL are particularly suited for use in single side band trans mission as used in mobile and fixed station use in Police, Fire, Utility, Forestry Transportation Services and Ama- teur Communications. The response cuts off sharply be- low 300 c.p.s. and above 3000 c.p.s. with an average rising characteristic for speech intelligibility. This re- sponse characteristic is especially effective in the pres- ence of noise.

The Model 440 and 440SL are, also, suitable for pub- lic address, call systems and radio telephone.

Copyright 1960, Shure Brothers, Inc.

274158 (8-63)

Installation: The Model 440 microphone has a standard 5/8"-27thread and can be mounted on any desk or floor stand.

In the Model 440SL assembl , the microphone and switch are pre-assembled, but tXe base and cable and plug assembly are separate. To assemble base t o switch use the following instructions:

I.Place microphone switch assembly in the recess

at the top of the base. Fasten switch t o base by means of special attachment screw included. Use a large screw driver or coin t o turn screw down tightly.

2.Insert cable-connector plug into microphone re- ceptacle. Turn locking ring down tightly.

3.Place cable in groove in the bottom rear of the base. Clamp cable t o base by means of the clamping plate and two machine screws which are furnished.

Connections: Most amateur equipment is wired t o use either VOX (voice o erated relay control) or a push- to-talk switch. The M o-!el 440SL has been designed Yo provide maximum flexibility with both types of operation.

SWITCH I

MOVEMENT

		BLACK
BLACK	.-	BLUE
	L	GREEN
RED

FIG. A

Printed in U.S.A.