Shure CB44 User Manual

222 HARTREY AVE.. EVANSTON. I L. 60204 U.S.A.

DATA

MODEL ~~44

AREA

CODE

312/328-9000

CABLE:

SHUREMICRO

CONTROLLED MAGNETIC@ CITIZENS BAND MICROPHONE

GENERAL

The Model CB44 LONG RANGER CONTROLLED

MAGNETIC microphone is designed especially for use

with Citizens Band transceivers in either mobile or

base stations. For clearer transmission and improved reliability, this small, rugged, dual-impedance microphone can be used to replace ceramic or dynamic

microphones supplied as original equipment.

Model CB44 provides crisp, undistorted voice response of high intelligibility and high output. Easy impedance selection at the end of the cable makes the microphone suitable for connection to either pedance or low-impedance (ceramic or dynamic) inputs.

The microphone fits naturally and comfortably in the hand and is not affected by heat or humidity. The ex-

clusive

ARMO-DURB case is immune to oil, grease, fumes, salt spray, sun, rust, and corrosion-and is outstanding in its ability to resist mechanical shocks and

vibration. The "Million-Cycle" leaf-type switch is de-

signed to withstand rigorous operating conditions and constant use.

The modular construction of Model CB44 provides exceptional ease of field serviceability. The cartridge, switch, and cable are of modular design which makes

them replaceable in a matter of minutes if replace-

ment is ever necessary.

Microphone Features:

Highly intelligible voice response Replaces either ceramic or dynamic original equip-

ment microphones

Dual impedance-matches either high- or lowimpedance inputs

Reliable high output CONTROLLED MAGNETIC

cartridge Unparalleled ruggedness and durability Tough ARMO-DUR case Modular construction for exceptional ease of field

service

Mounting bracket supplied-fits hang-up button on

back of microphone

high-im-

SHEET

CONNECTIONS

The internal connections of Model CB44 are shown

in Figure

CARTRIDGE

Refer to the Shure CB Wiring Guide enclosed with the microphone for detailed instructions for connecting the CB44 to your transceiver. If your unit is not

listed in the Guide, contact your dealer or Shure Brothers Incorporated for information. This microphone is not designed for use with transceivers requiring conductor shielded cable. Passage of the CB44 cable

through small-diameter connectors may be eased by

lubricating the outer jacket of the cable.

The general wiring procedure for transceiver con-

nections is as follows.

Relay or Switching Circuit:

GROUNDED SWITCHING

Most transceivers employ a grounded circuit to switch from the receive to the transmit position. To

connect the microphone to such a circuit, proceed as

follows.

ISOLATED SWITCHING In some transceivers, an isolated circuit is required

to switch power supply voltages rather than grounds.

If an isolated switching circuit is required, proceed as

follows.

4. Replace the switch button in the case front;

CPgCE

A-

- - -

- - - -

INTERNAL

GREEN

- - -

- - - - - -

- - - - -

CONNECTIONS

FIGURE

RED (TRANSMITTER)

- -

WHITE(L0W IMPEDANCE)

- -

',GREEN

WIELD

(HIGH IMPEDANCE)

(CHASSIS

CIRCUIT

GROUND)

five-

Connect the RED lead to the terminal used to complete the transmitter circuit.

Connect the BLACK lead to the terminal used to

complete the receiver circuit. This will usually be a ground return from the loudspeaker. If a microphone switching contact is not required for the loudspeaker ground, insulate (wrap with tape) the BLACK cable lead.

Connect the shield to chassis or circuit ground

of the transceiver (see Guide).

Remove the three No. 6 Phillips self-threading

screws from the back of the microphone case;

separate the case front and back and remove

the switch button.

Clip and remove the bare lead connecting switch

terminals

and 4 (see Figure

1).

Be sure not to

2 damage the continuation of the bare lead between switch terminal 2 and the case ground lug.

Unsolder the BLACK cable lead from switch ter-

minal

solder the BLACK cable lead to switch

terminal 4.

fasten the two case halves together with the previously removed Phillips screws.

27A1316

(PH)

1976,

Shure

Brothers

Inc.

(OVER)

Printed

U.S.A.

5. At the end of the cable, connect the RED lead to the isolated switch contact terminal used to

complete the transmitter circuit.

6. Connect the BLACK lead to the other isolated switch contact terminal used for power supply voltage.

7. Connect the shield to chassis or circuit ground of the transceiver (see Guide).

CAUTION

Make certain that the shield is not connected to chassis ground for those models where the Guide specifies the shield should be connected to circuit ground.

Microphone Audio Input Circuit:

LOW IMPEDANCE

Connect the WHITE cable lead to the low-impedance microphone audio input terminal. Insulate (wrap with tape) the GREEN lead.

HIGH IMPEDANCE (ceramic microphone replace-

ment)

Connect the GREEN cable lead to the

high-impedance microphone audio input terminal. Insulate (wrap with tape) the WHITE lead.

NOTE

The high-impedance connection will generally be used when replacing a ceramic microphone supplied with original equipment. If you do not know whether your transceiver requires a high-impedance or a

low-

impedance microphone, follow the wiring instructions for the low-impedance connection. Check whether there is sufficient output from your transceiver. If the

modulation output is too low, reconnect the

inicro-

phone for high impedance.

OPERATION

Model CB44 will operate satisfactorily under all or-

dinary conditions of humidity, heat, and cold. Dropping the microphone, or other severe mechanical shocks should be avoided.

Case

Light gray and black ARMO-DURE

Dimensions

See Figure 2

OVERALL

DIMENSIONS

FIGURE 2

Net Weight

358 grams (121/2 oz)

Packaged Weight

525 grams (18% oz)

MOUNTING

A mounting bracket for permanent installation is

supplied with each microphone (see Figure 3).

MOUNTING HOLES, CLEARANCE

FOR

10.2mm

113/32

IN.)

SPECIFICATIONS

Type

CONTROLLED MAGNETIC@

Frequency Response

200 to 5,000 Hz

lmpedance (at 1,000 Hz)

Dual. Microphone rating impedance is 150 ohms (190 ohms actual) and "High". For impedance selection, see section on Connections.

Load lmpedance Range

Low Impedance High Impedance

Output Level (at 1,000 Hz)

Open Circuit Voltage*

Power Level**

*O dB

**0 dB

Switch

Push-to-talk leaf-type switch to actuate microphone circuit and transceiver relay or switching circuit. Microphone circuit normally open in either high or low impedance.

Cable

1.8m

ft) extended, four conductor, two conductors

individually shielded, coiled cable

.........

.200 ohms to 1,000 ohms

....... .15 kilohms to 100 kilohms

IMPEDANCE

Low

......

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

volt per 100 microbars

1 milliwatt per 10 microbars

-32.0 dB mV) (225 mV)

(25

-51.0 dB

High

-13.0 dB

MOUNTING

BRACKET

FIGURE

FURNISHED ACCESSORY

Mounting Bracket

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

RK6MB

REPLACEMENT PARTS

Cartridge Switch Assembly Switch Button Cable Case Front Case Back

Grille and Chassis

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

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

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

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

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

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

.90A1677

.65A142B

70A4133

65A882D

90G1676

.65B884B

R44D

FULL ONE YEAR WARRANTY

Shure Brothers Incorporated ("Shure"), 222 Hartrey Avenue, Evanston, Illinois 60204, warrants to the owner of this product that it will be free, in normal use, of any defects in workmanship and materials for a period of one year from date of purchase. You should retain

proof of date of purchase. Shure is not liable for any consequential damages. If this Shure product has any defects as described above, carefully repack the unit

and return it prepaid to the above address. If you are

not in the United States, return the unit to your dealer or authorized Service Center for repair. The unit will

be repaired or replaced and returned to you promptly,

and if it cannot be repaired or replaced, you may elect

to receive a refund.