Shure 404B, 404C User Guide

SMU-

THE SOUND OF THE PROFESSIONALSS WORLDWIDE

MICROPHONES

Model 404 Series hand-held communications microphones are compact size, CONTROLLED MAGNETIC@ units designed for clear, crisp, natural voice response of high intelligibility.

Microphone Features:

Frequency response from 200 to 4,000 Hz especially suitable for voice communications use

Small, light and compact case, fits naturally and comfortably in the palm of the hand

Extremely sturdy, high impact, ARMO-DURB case, lighter and stronger than die-cast metal, comfortable to the touch in hot or cold weather

Heavy-duty, long-life, leaf-type push-to-talk switch Extra contact provided on switch for modification

to either normally shorted or normally open micro-

phone circuit

Durable rubber-jacketed coil cable

Rugged and dependable under all operating conditions

The Model 404 Series microphones are especially

recommended for indoor and outdoor paging systems,

all types of mobile communications, amateur radio, and all other applications where a rugged hand-held

microphone is needed. The microphones are also suit-

able for indoor and outdoor public address.

Model 404C is a high-impedance microphone with high output level, making it suitable for connection to high-impedance amplifier inputs when cable lengths

15.2m (50 ft) or less are needed.

Model 4048 is a low-impedance microphone and is recommended when long cable lengths are required or under conditions where severe hum pickup may exist. The Model 4048 may be connected directly to the input of

Model A95 Series Line Matching Transformer may be

used for connecting the Model 4048 to the input of a

high-impedance amplifier.

The 404 series microphones will replace certain

Shure 405 and 505 series microphones. Listed below

are CONTROLLED MAGNETIC communication microphones and recommended replacement.

222

HARTREY AVENUE

EVANSTON. ILLINOIS 60202-3696 U.S.A.

MODELS 404B AND 404C

AND

ELECTRONIC COMPONENTS

CONTROLLED MAGNETIC' HAND-HELD MICROPHONES

GENERAL

MOUNTING

A mounting bracket for permanent installation is

supplied with each microphone. (See Figure

MOUNTING

CLEARANCE

No.

APPLICATIONS

low-impedance amplifier, or a Shure

404C are shown in Figure 2.

(C13/16 IN.)

36.5

(1-7116 IN.)

4.7

(3/16 IN.)

/l~

The internal switch connections of Models 4048 and

(3/8 IN.) c(l-23/64

MOUNTING

FIGURE

CONNECTIONS

DATA

HOLES,

SCREWS

FOR

34.5

BRACKET

SHEET

10.3

(13/32 IN.)

INI

Model No.

CR4B, 4058, 5058 CR4C, 405C, 505C

Shure Replacement Microphone

4048 404C

Inc

MODEL 404B MODEL 404C

INTERNAL

CONNECTIONS

FIGURE

Printed

U.S.A.

Model 4048 is a low-impedance microphone with a four-conductor (two conductors shielded) coil-cord cable and a single-throw double-pole leaf-type switch to control the microphone circuit and an external relay or switching circuit. The GREEN and WHlTE leads are the "hot" conductors for balanced-line connection to the microphone circuit; the shield is connected to the

microphone circuit ground. The RED and BLACK leads control the relay or switching circuit. The microphone circuit of the switch is normally open but can be easily

modified for normally shorted operation.

The Model 4048 is wired for balanced-line operation and is recommended for use where long cable lengths are required or conditions where severe hum pickup

may exist. The Model 4048 can be connected directly to the input of a low-impedance amplifier or a Shure A95 Series Line Matching Transformer can be

coupling the Model 4048 to the input of a

used for

high-impedance amplifier. A two-conductor shielded cable can be used for extending only the microphone circuit. If both

the microphone and remote circuits are to be extended, a four-conductor cable should be used with two shielded conductors for the microphone circuit.

Model 404C is a high-impedance microphone with

a three-conductor coil-cord cable (one conductor

shielded) and a single-throw double-pole leaf-type switch to control the microphone circuit and an external relay or switching circuit. The WHlTE lead is the "hot" conductor for connection to the microphone circuit; the shield is connected to the microphone circuit ground. The

hangup button and the wire strain

relief are also grounded to the cable shield in the 404C only. The RED and BLACK leads control the relay or switching circuit. The microphone circuit of

the switch is normally shorted but can be easily

modified for normally open operation.

Model 404C can be used with any amplifier having a high-impedance microphone input. A single-conductor shielded cable can be used for extending only the microphone circuit. If both the microphone and remote circuits are to be extended, a three-conductor cable should be used with one shielded conductor for the microphone circuit. Cable lengths over

15m (50 ft) are

not recommended.

Model

circuit of the

4048

Circuit Modification:

The microphone

4048 is open when the microphone switch button is in the normal position. The microphone can be modified to provide a normally shorted microphone circuit as follows:

Remove the three No. 5-20 pan head screws from the back of the microphone case. (Caution: the

SWITCH

BUTTON,

MU-METAL

SHIELD7

FIGURE

the microphone cartridge is spring loaded and

care must be taken to hold the two halves of the microphone case firmly together.)

2. Separate the case front and back and remove the switch button. See Figure

Remove the No. 5-40 round head switch mount-

ing screw and lock washer holding the switch assembly in the case back.

4. Disconnect or clip the WHlTE cable lead from the switch solder lug.

5. Strip the insulation from the WHITE lead approxi-

(Y4

mately to the switch blade next to the blade with

in.) and solder the WHlTE lead

ttle GREEN lead connections. (This is the blade that the switch button pushes against.) The outside solder lug may be bent out of the way to aid soldering.

Reassemble the switch in the case back using the previously removed screw and lock washer.

Replace the switch button in the case back.

Making certain that the cartridge shield retaining springs are in the proper position and that no leads are pinched, place the case back on the case front and firmly press the cases together.. Fasten with the three previously removed

No. 5-20 screws.

Model

404C

Circuit Modification:

The microphone

circuit of the 404C is shorted when the microphone switch button is in the normal position. The microphone can be modified to provide a normally open microphone circuit as follows:

1. Remove the three No. 5-20 pan head screws from the back of the microphone case. (Caution: the

microphone cartridge is spring loaded and care must be taken to hold the two halves of the mi-

crophone case firmly together.)

2. Separate the case front and back and remove the switch button. See Figure

Remove the No. 5-40 round head switch mount-

ing screw and lock washer holding the switch assembly in the case back.

4. Disconnect or clip the WHlTE cable lead from the switch solder lug.

5. Strip the insulation from the WHlTE lead approxi-

(Y4

mately

in.) and solder the WHlTE lead to the unused solder lug at the bottom end of the switch.

NOTE: In certain instances where switch se-

quence is critical, it may be necessary to re-

move the effect of the shorted switch on the

cartridge. This is done by insulating the shorting

contacts with a piece of "spaghetti" tubing or a

piece of insulating tape.

Reassemble the switch in the case back using

the previously removed screw and lock washer.

Replace the switch button in the case back.

8. Making certain that the cartridge shield retaining springs are in the proper position and that no leads are pinched, place

€he case back on the

case front and firmly press the cases together.

Fasten with the three previously removed No. 5-20 screws.

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