PRODUCT SUPPORT MANUAL Y1-03-0057 (25-60-06) Overhaul Manual with Illustrated Parts List Rev. F EM-2BA™ Product No. 2206 FAA PMA Approved under A3-06-1405 Portable Safety Megaphone ACR Electronics, Inc. 5757 Ravenswood Road Fort Lauderdale, Fl 33312 +1(954) 981-3333 • Fax +1 (954) 983-5087 www.acrelectronics.com Email: Info@acrelectronics.
TABLE OF CONTENTS SECTION TITLE PAGE 1.0 Description 1 2.0 Technical Data 1 3.0 Operation 2 4.0 Cleaning 4 5.0 Battery Replacement 4 6.0 Testing 4 7.0 Trouble Shooting 5 8.0 Disassembly 6 9.0 Inspection Check 6 10.0 Repair 6 11.0 Assembly 7 12.0 Parts List 9 Figure 1 Block Diagram ACR/EM-2BA Portable Safety Megaphone 3 Figure 2 Illustrated Parts List ACR/EM-2BA Portable Safety Megaphone 8 ILLUSTRATION i 1 Y1-03-0057 Rev.
1.0 2.0 DESCRIPTION 1.1 The ACR/EM-2BA is a battery operated solid state megaphone specifically 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.
3.0 Batteries Six (6) standard 1½ volt “AA” cells Power Drain 25 milliamps static current 550 milliamps maximum current Frequency Response 500 to 3500 Hz Battery Test Circuits Visual Flashing Green LED OPERATION 3.1 To test the battery, squeeze the handle and note if the green LED (located near the volume control cap) is flashing. The batteries are useable as long as the LED flashes. 3.2 Hold the megaphone in one hand.
SPEAKER ASSEMBLY VOLUME CONTROL AUDIO AMPLIFIER SIREN CIRCUIT & BATTERY MONITOR MEGAPHONE SUB-ASSEMBLY MICROPHONE ASSEMBLY - + + N.O. N.C. HANDLE SWITCH + BATTERY PACK - FIGURE 1 BLOCK DIAGRAM ACR/EM-2BA PORTABLE SAFETY MEGAPHONE 4.0 CLEANING 4.1 5.0 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 cloth dampened with isopropyl alcohol.
5.2 Battery replacement is accomplished by removing three set screws (3) while holding the microphone and mouthpiece assembly (2) in place. The six battery 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. 5.3 Replace microphone and mouthpiece assembly (2). Align keyway and secure with the three set screws (3).
.0 TROUBLESHOOTING 7.1 Testing procedure for locating defects is given in paragraph 6.0. Possible faults and corrections are summarized below for ready reference. TROUBLE POSSIBLE CAUSE CORRECTION No sound from speaker when handle is squeezed (Step 6.
.1.6 9.0 INSPECTION / CHECK 9.1 10.0 Inspect unit for any evidence of damaged parts, loose mountings or broken leads and dirty electrical contacts. REPAIR 10.1 11.0 Disassembly in steps 8.1.1 through 8.1.5 above is sufficient to examine the megaphone for faults and testing. Further disassembly is not recommended. The megaphone consists of three major sub-assemblies; the Microphone and Mouthpiece Assembly, the Megaphone Sub-Assembly, and the Horn and Speaker Assembly.
11.1.7 Replace microphone and mouthpiece assembly (2). Align keyway, and secure with the three setscrews (3). 11.1.8 Steps 11.1.1 through 11.1.7 complete the assembly of the megaphone. After assembly, test unit in accordance with Paragraph 6.0, Testing. 8 Y1-03-0057 Rev.
FIGURE 2 ACR / EM-2BA PORTABLE SAFETY MEGAPHONE ILLUSTRATED PARTS LIST 8
12.0 PARTS LIST 12.1 ITEM QTY Replaceable parts are illustrated in Figure 2, and listed below in the table. Part numbers shown in the “Part Number” column may be ordered from ACR unless another manufacturer’s name is given in parenthesis 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.
