ACR Electronics ACR-EM-1D, ACR-EM-1A User Manual Rev Y

Product Support Manual

ACR/EM-1A, ACR/EM-1D™

Portable Safety Megaphone

FAA PMA Approved under A3-06-1402-

Product No. 2204, 2208

Y1-03-0014 Rev. Y

(25-60-01)

The technical data in this document (or file) is controlled for export under the Export

Administration Regulations (EAR), 15 CFR Parts 730-774, ECCN: EAR99. Violations of these

laws may be subject to fines and penalties under the Export Administration Act.

REV DESCRIPTION DATE APVD.

L Format changes, add ACR/EM-1D content. 9/8/98 T. Martin

M Update parts list to reect design changes. 5/20/99 T. Martin

N Update and make corrections to parts list. 7/13/99 T. Martin

P Update to assign 4-digit product codes to parts list. 12/8/99 L. Subrattee

R Add FAA approval info to front cover. 4/27/04 T. Martin

U Update to add revision table and updated formatting. 2/7/08 T. Martin

V Updated for rebranding 4/3/09 T. Martin

W Updated to add export admin regulatory statement 11/24/09 T. Martin

Y Updated to make product references more consistent 1/15/10 T. Martin

IF YOU HAVE ANY TROUBLE WITH

YOUR NEW MEGAPHONE, DO NOT RETURN

IT TO THE STORE!

CALL ACR ELECTRONICS AT

[phone]. WE WILL HELP YOU

RESOLVE ANY PROBLEMS YOU MAY BE

EXPERIENCING. MANY QUESTIONS CAN BE

ANSWERED OVER THE PHONE.

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TABLE OF CONTENTS

SECTION 1 – DESCRIPTION 4

1.1 Options Matrix 4

SECTION 2 – OPERATION 4

2.1 Battery Monitor 4

SECTION 3 – MAINTENANCE 5

3.1 Cleaning 5

3.2 Battery Replacement 5

SECTION 4 – TESTING, TROUBLESHOOTING & REPAIR 5

4.1 Testing 5

4.2 Repair 6

SECTION 5 – DISASSEMBLY & ASSEMBLY 6

5.1 Disassembly 6

5.2 Assembly 7

SECTION 6 – TECHNICAL DATA 7

SECTION 7 - PARTS LIST 8

APPENDIX - WARRANTY, USEFUL LIFE, NOTICES 10

1. Limited Warranty 10

2. Useful Life Policy 10

3. Notices 10

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SECTION 1 – DESCRIPTION

The ACR/EM-1A or ACR/EM-1D is a battery operated solid state megaphone specically

developed for use in enclosed areas such as in the interior of an aircraft or ship cabin. It
has been designed to minimize regenerative acoustic feedback that results in whistling and
other oscillations of this nature. It has a 90° sound projection angle to direct the sound to

persons in its immediate vicinity, as well as in the rear sections of any aircraft. The amplier

frequency band-pass has been selected to produce a crisp, clear reproduction of voice

signals. The operating power level is also sufcient to provide adequate sound under high
ambient noise level conditions without being over-powering. Specic attention has been

given to the physical size so that it can be used effectively in a crowded environment.

The integrated circuit amplier only uses a small current when turned “ON”. This extends the

life of the batteries so that several hours of operation may be expected when used normally

in an intermittent manner. A simplied block diagram of the megaphone is shown in Figure

1 (shown on page 5).

The ACR/EM-1A & ACR/EM-1D are the same except for installed options:

1.1 Options Matrix

MODEL MANUAL GAIN ALARM ACTUATOR BATTERY MONITOR

Visual Audible

ACR/EM-1A Yes Yes Yes No

ACR/EM-1D Yes No Yes Yes

SECTION 2 – OPERATION

A siren, incorporated into the megaphone, is automatically activated by unplugging the alarm
plug pin. (ACR/EM-1A only)

Note: A long lanyard with an alarm plug pin is supplied with the megaphone for use
as an anti-theft alarm (optional).

Squeezing the handle stops the siren, and the megaphone is ready for use. Re-insert the
alarm pin so that the alarm will not be reactivated when the handle is released.

Hold the megaphone in one hand. Place your mouth almost in contact with the microphone

mouthpiece at the rear of the assembly. Squeeze the handle, which will ex slightly, turning
the megaphone “ON” and speak slowly with loud, crisp, clear tones.

Adjust the volume control knob to a suitable sound level. The volume control may be adjusted
with the thumb of the same hand holding the megaphone.

When not in use, carry the megaphone by the neck strap, attached to top of unit.

2.1 Battery Monitor

Two types of battery monitors are available on the ACR/EM-1 series megaphones.

Visual - when the megaphone is activated by squeezing the handle, a green LED
indication means the remaining battery capacity is greater than 50% of initial capacity. If the
green LED is out, replace batteries.

Audible - when the megaphone is activated by squeezing the handle, a chirp heard in
the speaker means the remaining battery capacity is greater than 50% of initial capacity. If
the beep is not present, replace the battery. (ACR/EM-1D only)

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FIGURE 1

VO LU ME

CO NT RO L

MI CR OPH ON E

AS SE MB LY

AU DIO AM PL IFIE R

SIREN CIR CU IT &

BA TT ER Y M ON ITO R

ME GA PH ON E

SU B-A SS EM BLY

BA TT ER Y

PA CK

(6 x A A)

LE D

VISUA L

BA TT ER Y

CH EC K

SP EAK ER

AS SEM BLY

N.O .

N.C .
HA NDL E
SW ITC H

AL ARM

PL UG PIN

+ +

+ -

-

-

*

BLOCK DIAGRAM

ACR/EM-1A, ACR/EM-1D PORTABLE SAFETY MEGAPHONE

SECTION 3 – MAINTENANCE

3.1 Cleaning

External surfaces of the megaphone may be cleaned with a soft cloth, dampened in a
solution of mild household detergent. Do not immerse in water or use strong solvents. Clean
electrical contacts with a cloth dampened with isopropyl alcohol.

3.2 Battery Replacement

The power supply used in the megaphone consists of six standard 1½ volt “AA” size batteries.
Current drain is minimal (12 mA) with the megaphone “ON”, and increases when the user

speaks into the microphone.

Battery replacement is accomplished by removing three set screws (2) while holding the
microphone and mouthpiece assembly (1) in place. The six cells, contained in three tubes
with two cells per tube, are immediately accessible and will drop out when the megaphone
is tilted. New batteries may be dropped into the tubes, observing polarity marking adjacent
to each tube.

Replace microphone and mouthpiece assembly (1). Align keyway and secure with the three
set screws (2).

CAUTION: Observe polarity of cells carefully before replacement.

SECTION 4 – TESTING, TROUBLESHOOTING & REPAIR

4.1 Testing

1. Squeeze the handle. If a clicking sound is heard, the speaker is operating.

Note: The megaphone consists of three major assemblies; the microphone and
mouthpiece assembly, the megaphone sub-assembly, and the horn and speaker
assembly. To locate a defect, follow the procedure outlined below:

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2. Remove the pin that activates the siren. If the alarm is of normal amplitude and sound

character, the amplier and siren circuitry are functioning properly. If the amplication
is low, check the batteries and then the amplier. If the sound character is abnormal,

check the batteries and then the siren circuitry. (ACR/EM-1A only)

3. If no sound is heard, remove the microphone and mouthpiece assembly and the
batteries. Check that both the microphone and battery contacts are clean. If not, clean
with a mild, non-abrasive cleaner such as alcohol.

4. Test amplier and speaker assembly by replacing the microphone with a spare

microphone assembly. If no sound can be produced after microphone replacement, it

may be assumed that the amplier or speaker assembly is defective.

5. To test the speaker, disassemble the speaker. Unplug the wires and apply 1 ½ volts
intermittently across the speaker. If no clicks are heard, the speaker is defective.

Possible faults and corrections are summarized below for ready reference.

TROUBLE POSSIBLE CAUSE CORRECTION

No sound from speaker
when handle is squeezed
(Step 1)

No siren when alarm
pin is pulled (Step 2)
(ACR/EM-1A only)

Sound is abnormally low or
distorted

Speaker does not respond to
Step 5

Exhausted batteries, defective
microphone, speaker or

amplier assembly

Exhausted batteries, defective
siren circuitry or defective

amplier

Exhausted batteries or wrong
polarity of battery series

Defective speaker Replace speaker

Replace defective component

Replace defective component

Check proper insertion of
batteries or replace batteries.

4.2 Repair

The megaphone consists of three major sub-assemblies; the microphone and mouthpiece
assembly, the megaphone sub-assembly, and the horn and speaker assembly. Repairs are
restricted to the replacement of these defective sub-assemblies or the batteries and lanyard
assemblies.

SECTION 5 – DISASSEMBLY & ASSEMBLY

5.1 Disassembly

Megaphone should be disassembled for repair or replacement of components only.

1. Remove microphone and mouthpiece assembly (1) by removing the three set
screws (2).

2. Remove battery cells (3) from the three tubes by tilting megaphone to allow cells to
drop out into the hand.

3. Unplug alarm plug pin (5) from side of housing. (ACR/EM-1A only)

4. Remove volume control knob (4) (pulls off).

5. Remove the three oval head screws (10) at periphery of the speaker end of the
housing (14).

6. Extract speaker (6) and megaphone assembly (9) by rstly turning horn (17) clockwise

45°. Pull entire assembly gently until it stops. Turn horn (17) counterclockwise 45°
then pull the entire assembly out.

7. Separate Speaker Assembly (6) and Megaphone Subassembly (9) by rstly
unplugging the speaker wires from the “out” header. Remove hex screw that holds the

assemblies together.

8. FURTHER DISASSEMBLY IS NOT RECOMMENDED.

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Inspect unit for any evidence of damaged parts, loose mountings or broken leads,
and dirty electrical contacts.

5.2 Assembly

1. Attach Horn (17) and Speaker Assembly (6) to Megaphone Subassembly (9). Ensure
alignment with location pins. Pass speaker wires through the provided slot.

2. Plug speaker connector into the “out” header on PCB.

3. Push entire assembly gently into the housing (14), until it stops. Turn clockwise 45°
and push all the way in. Turn counterclockwise 45° and align holes.

4. Secure with screws (10).

5. Replace volume control knob (4) on volume control shaft.

6. Plug the alarm plug (5) attached to lanyard into jack in the side of the case near
volume control. (ACR/EM-1A only)

7. Replace the six batteries (3) in three tubes at microphone end of megaphone case.

CAUTION: Observe polarity of batteries during installation procedure (see
instructions on battery tubes).

8. Replace microphone and mouthpiece assembly (1). Align keyway, and secure with the
three setscrews (2).

9. Assembly is complete. Test unit in accordance with Section 4.1.

SECTION 6 – TECHNICAL DATA

Dimensions 5.5” max diameter bell, 11.5” max long

Weight 2.3 lbs., including batteries

Materials Horn, handle – Anodized Aluminum

Housing – Aluminum

Attachment – Neck strap at top of unit

Gain Control Thumb operated

Amplier Integrated circuit, 2 watts power output

Speaker Re-entrant horn and driver type

input power ve (5) watts

90° dispersion angle

Microphone High Sensitivity

Batteries Six (6) standard 1½ volt “AA” cells

Power Drain 12 milliamps static current

550 milliamps maximum current

Frequency Response 500 to 3500 Hz

Anti-Removal Alarm (ACR/EM-1A
only)

Alarm Actuator (EM-1A only) Plug pin, retained by nylon cord

Battery Test Circuits Visual Flashing Green LED

Warbling tone 500 – 1200 Hz

Acoustical Beep (ACR/EM-1D only)

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SECTION 7 - PARTS LIST

8

7

6

17

10

16
4

12
2

3

1

9

15

11

14

13

5

FIGURE 2

ACR/ EM-1A, ACR/EM-1D PORTABLE SAFETY MEGAPHONE

ILLUSTRATED PARTS LIST

Replaceable parts are illustrated in Figure 2 (shown above) and listed in the table (shown

on page 9). Part numbers shown in the “Part Number” column may be ordered from ACR
unless another manufacturer’s name is given in parentheses in the “Description” column.

In this case, replacement parts can be obtained directly from the original manufacturer.
Standard parts (MS-, AN-, etc.) and commercially available hardware (‘Commercial’) should
be obtained from commercial sources.

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ITEM QTY NOMENCLATURE ORDER SPARE PARTS

ACR/EM-1A
S/N < 9000

ACR/EM-1A

S/N ≥ 9000

ACR/EM-1D
ALL S/N

1 1 Microphone & Mouthpiece Assy 9211 9211 9211

2 1 Socket Setscrew Kit 9416 9416 9416

3 6 Battery AA Alkaline Commercial Commercial Commercial

4 1 Knob, control 9022 9022.1 9022.1

5 1 Plug pin, Alarm Included in 9161 & 9164 N/A

6 1 Speaker Assembly 9417

9418 9418

(upgrade kit)

7 3 Screw, Self tap (#4 x ¾) Commercial N/A N/A

8 2 Wire leads speaker (#26AWG) Commercial N/A N/A

9 1 Megaphone Subassy 9417

9420 9422

(upgrade kit)

10 3 Screw Machine (#4-40 x 3/8) Commercial Commercial Commercial

11 1 Handle Kit 9423 9423 9423

12 / 16 1 Strap Assembly Kit 9233 9233 9233

13 1 Lanyard Assembly, Anti theft 9164 9164 N/A

14 1 Housing Megaphone A1-18-1149 A1-18-1149 A1-18-1151-1

15 1 Lanyard Assembly, Siren 9161 9161 N/A

17 1 Horn, Megaphone A1-17-0809 A1-17-0809 A1-17-0809

*S/N ≥ 9000 are date coded 4/99 +

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Y1-03-0014 Rev. Y

APPENDIX - WARRANTY, USEFUL LIFE, NOTICES

A.1 Limited Warranty

This product is warranted against factory defects in material and workmanship for a period
of 1 (one) year* from date of purchase or receipt as a gift. During the warranty period ACR
Electronics, Inc. will repair or, at its option, replace the unit at no cost to you for labor,
materials and return transportation from ACR. For further assistance, please contact our
Technical Service Department at ACR Electronics, Inc., 5757 Ravenswood Road, Fort
Lauderdale, FL 33312-6645. Email: [e-mail], Fax: [phone],
Telephone: [phone].

This warranty does not apply if the product has been damaged by accident or misuse, or as a

result of service or modication performed by an unauthorized factory. Except as otherwise

expressly stated in the previous paragraph, THE COMPANY MAKES NO REPRESENTATION
OR WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, AS TO MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, OR ANY OTHER MATTER WITH RESPECT TO
THIS PRODUCT. The Company shall not be liable for consequential or special damages.

To place the warranty in effect, register online at www.acrelectronics.com or return the
attached card within 10 days.

*Five years for the following products: EPIRB, PLB, S-VDR, SSAS.

A.2 Useful Life Policy

The typical service life of a properly maintained Product is limited to 12 years from date of
manufacture. Products that are 12 years and 1 month or older from date of manufacture
will not be serviced by ACR or our Battery Replacement Centers. A Product that is 12 or

less years old from date of manufacture will be serviced as long as the unit appears t to be
placed back into its nal operational cycle. Service includes the replacement of those items
that must be replaced at service intervals and the verication that the device appears to be in

good mechanical and electrical working condition by an ACR authorized service technician.

A.3 Notices

ACR Electronics diligently works to provide a high quality Product Support Manual, however,
despite best efforts, information is subject to change without notice, and omissions and
inaccuracies are possible. ACR cannot accept liability for manual contents. To ensure that
you have the most recent version of the Product Support Manual, please visit the ACR
website at www.acrelectronics.com.

©2009 by ACR Electronics, Inc., part of Cobham plc. All rights reserved. Reproduction in
whole or in part is permitted only with permission of ACR Electronics, Inc.

Ongoing product improvements may change product specications without notice.

Trademarks or registered trademarks are the property of their respective owners.

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