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If you are experiencing an unusually high amount of RFI, you
may perform the following steps to help reduce the RFI:
1. Make sure that both the control head and amp are securely attached to good
chassis ground (i.e. no paint in-between the chassis and the grounding
terminal).
2. Keep the siren control head and the police radio as far away from one another
as is practical.
3. Check that the police radio antenna wire makes a right angle from the back of
the police radio and runs on one side of the vehicle. The communications cable
for the siren should make a right angle out of the back of the control head and
exit in the opposite direction from both the police radio antenna wire and the
police radio power wires.
4. Excess communication cable from the control head to the amp should be tightly
bound back near the amplifier box.
5. An RFI choke (www.digikey.com P/N: 240-2066; STAR P/N: P30039-57) can
be placed around the communications cable at the back of the siren amplifier
box.
6. You can also place a second RFI choke around the Red and Black wires exiting
the siren amplifier box.
S I R E N C O N T R O L H E A D
RADIO
R A D I O P O W E R W I R E S
A N T E N N A L E A D
S I R E N C O M M U N I C A T I O N S C A B L E
S I R E N P O W E R W I R E S
S I R E N A M P
RFI CHOKES
B A T T E R Y
