Shure 407A, 407B User Guide

222 HARTREY AVE.. EVANSTON, IL. 60204 U.S.A.

AREA CODE 312/866-2200 . CABLE: SHUREMICRO

TWX: 910.231-0048 TELEX: 72.4381

DATA

SHEET

MODELS 407A

CONTROLLED MAGNETIC@ HAND MICROPHONES

inputs, the 4078 for amplifiers with low-impedance inputs.

supplied with each microphone. (See Figure

INSTALLATION AND CONNECTIONS

A mounting bracket for permanent installation is

MOUNTING HOLES, CLEARANCE FOR No.

SCREWS

and

4078

10.2

rnrn

(13/32

IN.)

GENERAL

The 407 series of microphones are high-quality, ex-

tremely reliable hand-held CONTROLLED

MAGNETIC@ microphones designed for clear, crisp, natural voice response of high intelligibility. This series of microphones features professional design, small size, light weight, and modular construction, providing extreme dependability and exceptional ease of field service.

The modular construction of the 407's accounts for their tremendous ease of field serviceability. The cartridge, switch, and cable are of modular design which makes them replaceable in a matter of minutes if replacement is ever necessary.

The unit fits naturally and comfortably in the hand

and is not affected by heat or humidity. Exclusive ARMO-DUR@ case is immune to oil, grease, fumes, salt spray, sun, rust and corrosion-and is outstanding

in its ability to withstand mechanical shocks and vibration. "Million-Cycle" leaf-type switch is double-pole, single-throw, designed to withstand severe operating conditions and constant usage.

Microphone Features:

Highly intelligible voice response Unparalleled ruggedness and reliability

CONTROLLED MAGNETIC@ element

ARMO-DURe case "Million-Cycle" leaf-type switch controlling

microphone and external relay or switching circuits

Modular construction Exceptional ease of field service Life-time hang-up button and mounting bracket TRIPLE FLEX@ cable provides 3 to 4 times the flex life of any previously available coiled cords

another Shure first

APPLICATION

The Model 407A and 407B microphones are highly recommended for all types of mobile communications; for hams; industrial and commercial paging; outdoor public address systems; and all applications where a rugged hand microphone is required. The Model 407A is a high-impedance microphone with high output

level, making it suitable for public address amplifier

installations where a cable length of

15.2m (50 ft) or

less is needed. The Model 407B is a low-impedance

microphone and is recommended where long cable

lengths are required. The 407A and 407B are both suited for use with transistor or vacuum tube amplifiers, the 407A for amplifiers with high-impedance

Inc.

MOUNTING BRACKET

FIGURE

The internal switch connections of Models 407A

and 407B are shown in Figure 2.

The Model 407A is a high-impedance microphone with a three-conductor coiled-cord cable (one conductor shielded) and a double-pole single-throw leaftype switch to control the microphone circuit and an external relay or switching circuit. The RED lead is the "hot" conductor for connection to the microphone circuit; the shield is connected to the microphone circuit ground. The NATURAL and BLACK leads control the relay or switching circuit. The microphone circuit of the switch is normally shorted but may be easily modified for normally open operation.

The Model 407B is a low-impedance microphone with a four-conductor coiled-cord cable (two conductors shielded) and a double-pole single-throw leaftype switch to control the microphone circuit and an external relay or switching circuit. The WHITE and GREEN leads are the "hot" conductors for

balancedline 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 may be easily modified for normally shorted operation.

Modification of Microphone Circuit

The microphone circuit of the Model 407A is shorted

when the microphone switch button is in the normal

position. The microphone section of the switch has an extra leaf which may be used in modifying the Model 407A to have a normally open microphone circuit. To

modify the Model 407A for a normally open microphone

circuit, proceed as follows:

Remove the three No. 6 Phillips self-threading

screws from the back of the microphone case.

2. Separate the case front and back and remove the microphone switch button.

3. Unsolder or clip the RED cable lead from the

lower switch solder lug. (See Figures 2 and 3)

4. Solder this RED cable lead to the upper unused

terminal lug. (See Figures

and 3)

NOTE: In certain instances, if the switch sequence is critical, it may be necessary to remove the effect of the shorted switch on the cartridge. This can be done by insulating the blade of the switch with the BLACK wire and shield attached, from the blade of the switch with RED wire attached. This can be done by sliding a piece of "spaghetti"

Printed

U.S.A.

CODED TERMINAL

MODEL

407A

INTERNAL

CONNECTIONS

MODEL

4078

FIGURE 2

tubing over the switchblade or with a piece of

insulating tape.

Place the microphone switch button in the normal position on the case-front. Place the case-back on

the case-front and firmly press cases together.

Fasten the case-back and case-front with the No. 6 Phillips self-threading screws previously removed.

The microphone circuit of the Model

4078 is normally open when the microphone switch button is in normal position. The microphone switch of the

4078 may be rewired to have a normally shorted microphone circuit. To modify the Model 407B for a normally shorted microphone circuit, proceed as follows:

1. Remove the three No.

Phillips self-threading

screws from the back of the microphone case.

2. Separate the case front and back and remove the microphone switch button.

Unsolder or clip the WHITE cable lead from the

upper switch solder lug. (See Figures 2 and 3)

4. Solder the WHITE cable lead to the lower terminal

lug, the one with the YELLOW lead going to the

microphone cartridge. (See Figures 2 and 3)

Place the microphone switch button in the normal

position on the case front. Place the case-back on

the case-front and firmly press the cases together. Fasten the case-back to the case-front with the Phillips self-threading screws previously removed.

OPERATION

The Models 407A and 4078 will operate satisfactorily under all ordinary conditions of humidity, heat, and cold. Dropping the microphones or other severe mechanical shocks should be avoided.

Output Level

(at 1,000

Hz)

407A 4078

Open Circuit Voltage* Power Level

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

.....

-13.5 dB -33.0 dB (210

mV) (22 mV)

-52.0 dB

*O dB = 1 volt per 100 microbars

**0 dB

1 milliwatt per 10 microbars

Impedance

407A-Microphone impedance is "High". 407B-Microphone rating impedance is 150 ohms

(200 ohms actual).

Load lmpedance Range

Minimum Recommended

407A 407B

...........

.15 kilohms 100 kilohms

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

200 ohms 1,000 ohms

Cable

1.8m

ft), attached, coiled cable 407A-3-conductor, 1-conductor shielded 407B-4-conductor, 2-conductor shielded

Case

Two-tone light gray and charcoal ARMO-DUR@

Dimensions

See Figure 5

~MM (11161N)

(2-5/81Nl

OVERALL

DIMENSIONS

24MM (3/32 IN1

FIGURE 5

Net Weight

312 grams (1 1 oz)

Packaged Weight

510 grams (1 Ib, 2 oz)

REAR

VIEW

CHASSIS

FIGURE

SPECIFICATIONS

Frequency Response

300 to 4,000 Hz (see Figure 4)

.,o

-10

TYPICAL

FREOUW

FREQUENCY

FIGURE

lpoo

*Lmz

(CASE

UPPER LUG LOWER LUG

REMOVED)

RESPONSE

FURNISHED ACCESSORY

Mounting Bracket

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

RK6MB

REPLACEMENT PARTS

407A 4078

Cartridge .99AN556 99AL556 Cable .70A3088 70A4107 Switch .90A3507 90A3507

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

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

GUARANTEE

This Shure product is guaranteed in normal use to

be free from electrical and mechanical defects for a

period of one year from date of purchase. Please

retain proof of purchase date. This guarantee includes all parts and labor. This guarantee is in lieu of any and all other guarantees or warranties, express or implied, and there shall be no recovery for any consequential or incidental damages.

SHIPPING INSTRUCTIONS

Carefully repack the unit and return it prepaid to:

Shure Brothers Incorporated Attention: Service Department

1501 West Shure Drive

Arlington Heights, Illinois 60004

If outside the United States, return the unit to your dealer or Authorized Shure Service Center for repair. The unit will be returned to you prepaid.