ACR&Artex Megaphone - Manual (Page 6)

 Y1-03-0014 Rev. AC
. 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 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 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)
Exhausted batteries, defective
microphone, speaker or
amplifier assembly
Replace defective component
No siren when alarm
pin is pulled (Step )
(ACR/EM-1A only)
Exhausted batteries, defective
siren circuitry or defective
amplifier
Replace defective component
Sound is abnormally low or
distorted
Exhausted batteries or wrong
polarity of battery series
Check proper insertion of
batteries or replace batteries.
Speaker does not respond to
Step 5
Defective speaker Replace speaker
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 ().
. 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).
. Extract speaker () and megaphone assembly (9) by firstly 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 () and Megaphone Subassembly (9) by firstly
unplugging the speaker wires from the “out” header. Remove hex screw that holds the
assemblies together.
8. FURTHER DISASSEMBLY IS NOT RECOMMENDED.