Shure 440 User Manual

222

HARTREY AYE . EVANSTON

EVANSTON PHONE DA

89000

ILL.

CABLE

CHICAGO PHONE

SHUREMICRO

1600

DATA SHEET

440

Models

and

440SL

General:

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

phone, a grip-to-talk, slide-to-lock switch (see operation)

and a desk stand. The grip-to-talk switch is similar to the

A88A,

Shure 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

grip bar locks the switch. The switch cannot be accidently 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:

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 Amateur Communications. The response cuts off sharply below 300 rising characteristic for speech intelligibility. This response characteristic is especially effective in the presence of noise.

The Model 440 and

lic address, call systems and radio telephone.

Model 440 and Model 440SL microphones

440SL

an integral assembly of a micro-

having the same long-life features to with-

pressed, a positive downward pressure on the

The Model 440 and the Model 440SL

c.p.s. and above 3000 c.p.s. with an average

440SL are, also, suitable for pub-

Installation:

standard desk or floor stand.

switch are pre-assembled, but plug assembly are separate. To assemble base to switch use the following instructions:

5/8"-27

In the Model

Place microphone switch assembly in the recess

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

tightly.

Insert cable-connector plug into microphone re-

ceptacle. Place cable in groove in the bottom rear of the

3. base. Clamp cable to base clamping plate and two machine screws which are furnished.

Connections:

use either to-talk switch. The Mo provide maximum flexibility with both types of operation.

VOX

The Model 440 microphone has

thread and can be mounted on any

440SL assembl , the microphone and

e base and cable and

Turn locking ring down tightly.

means of the

Most amateur equipment is wired to

(voice o erated relay control) or a push-

el 440SL has been designed Yo

SWITCH

MOVEMENT

BLACK

RED

FIG.

BLACK

BLUE GREEN

Printed in

U.S.A.

Using the microphone as supplied, the grip-to-

talk switch operates both the microphone circuit and an external relay or control circuit. Connect all leads to the proper terminals of the equip-

ment. (See equipment manual). By using the white and shield connecting the shield and black leads together and connecting to the proper terminals, the gripto-talk switch will operate the microphone circuit

but the external relay or control circuit is not

operated, and the microphone can be

operated with the microphone being muted by the switch.

By the minor modification of cutting the green

lead (see Figure

microphone circuit

action and the switch will operate the external

relay or control circuit in push-to-talk operation. The microphone can be used for VOX operation and the microphone can not be muted.

The modification is made as follows:

Remove the integral assembly of the microphone

and switch from the desk stand. Remove the 4-40 phillips head screw from the bot-

2. tom of the switch case and pull out the bakelite receptacle.

Disconnect the green wire from pin

3. bare end of the wire, and put the wire back into the switch case.

Replace the bakelite receptacle and the 4-40

4. head screw.

5. Assemble the microphone and switch to the desk stand.

To obtain optimum flexibility between either VOX

or push-to-talk operation.

The Shure Model phone by placing a switch in the black lead from the receptacle. The grip-to-talk switch of the micro~hone can then be used to o~erate the microbhone circuit and the external day or control circuit can be operated or NOT operated by grip-to-talk switch

A87K switch. This will permit instant change-

the over from VOX operation to push-to-talk operation and to mute the microphone in either operation.

still

leads (microphone circuit) or by

VOX

and instructions below) the

removed from the switch

#3,

insulate the

phillips

A87K Kit will modify the micro-

changing the position of

retain the microphone circuit switch

440SL microphone, as supplied, has a switch

The

which as a grip-to-talk switch, grasp t e switch with and pressing the bar with fingers. converted to a grip-to-talk, slide-to-lock switch. This may be done by loosening the number 5-40 chine screw, directly beneath the switch ar, rotating the "Stop-Plate" one-half turn and retightening the machine screw. To lock, press the bar and simultaneously apply force downward with the index finger until the switch bar slides and slide bar up with fingers.

a momentary contact non-locking) ty e. For use

desired, the switch may be

Philli

s Head ma-

locked in position. To unlock,

Specifications:

MODEL 440SL

9%"

(238.lmm)

(177.8mm)

(127rnm)

Gray and Chrome

2v2 Ibs.

Ibs. (2722g)

134g)

Height Overall

Length Overall Width Overall Finish

Net Weight

(2.ln-t) Cable

Shpg. Weight with

with

(2.lm) Cable

MODEL 440

2s (61.lmm) Dia.

3%" (82.6mm)

2s (61.lmm) Dia.

Gray and Chrome

3/4

Ib. (340g)

Ifi

Ibs. (6809)

Voltage Sensitivity

Model 440 and 440SL Open circuit voltage

E.I.A.

Microphone Rating

Sensitivity

odb

'8"

E.I.A.

Microbar = one dyne per square centimeter Frequency Response: 300 to 3000 Recommended Load Impedance:

100,000 ohms or more

............................

volt per microbar

Standard SE-105 August 1949

.........

52.5

142.3 db,*-.

c.p.s.

(2.38 mv)

.!.

-7,

Operation:

care are necessary in the operation of the Models 440

440SL Microphones. They will operate satisfactorily

and under ordinary conditions in hot and cold climates. To retain the full strength of the permanent magnet and to maintain alignment of structure, dropping or other severe mechanical shocks should be avoided.

No special precautions beyond ordinary

Guarantee:

free from electrical and

of one year from date of shipment from the factory, provided all instructions are complied with fully. In case of damage, return the microphone to the pairs. Our guarantee

is opened.

Each micro hone is guaranteed

mec

anical defects for a period

fadory for re-

voided

the microphone case