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3. Maintenance
3.1 Cleaning
External surfaces of the megaphone may be cleaned with a soft cloth, dampened in a solution of mild
detergent. Do not immerse in water or use strong solvents. Clean electrical contacts with a cloth
dampened with isopropyl (rubbing) 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 while holding the microphone and
mouthpiece assembly 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. Align keyway and secure with the three set screws.
CAUTION: Carefully observe polarity of cells before replacement.
4. Testing, Troubleshooting and Repair
4.1 Testing
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 outlines below:
1. Squeeze the handle. If a clicking sound is heard, the speaker is operating.
2. Remove the pin that activates the siren. If the alarm is of normal amplitude and sound character,
the amplifier and siren circuitry are functioning properly. If the amplification is low, check the
batteries and then the amplifier. 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 isopropyl (rubbing) alcohol.
4. Test amplifier 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 amplifier or speaker assembly is defective.
5. To test the speaker, disassemble the speaker. Unplug the wires and apply 1½ volts intermittently
across the speaker. If no clicks are heard, the speaker is defective.
Possible faults and corrections are summarized below for ready reference.
Y1-03-0340 Rev. C
ACR ELECTRONICS, INC.
Product Support Manual
Portable Safety Megaphone
Company Confidential
7
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