______________________________________________________________________________
____________________________________________________________________________
Page 4-50
LMM for the Kodiak 100
190-02102-00 Rev.4
4.7.3.3 VHF COM / GPS Interference
In some installations VHF COM transceivers, Emergency Locator Transmitter (ELT)
antennas, and Direction Finder (DF) receiver antennas can re-radiate through the GPS
antenna. The GIA COM does not interfere with its own GPS section. However,
placement of the GA 56 antenna (or other comparable antenna) relative to a COM
transceiver and COM antenna (including the GIA COM antenna), ELT antenna, and DF
receiver antenna is critical.
Use the following guidelines in addition to others in the GIA Installation Manual when
locating the GIA and its antennas:
• GPS Antenna - Locate as far as possible from all COM antennas and all COM
transceivers (including the GIA COM), ELT antennas, and DF antennas. The GPS
antenna is less susceptible to harmonic interference if a 1.57542 GHz notch filter is
installed on the COM transceiver antenna output.
• Locate the GIA as far as possible from all COM antennas.
• If a COM antenna is found to be the problem, a 1.57542 GHz notch filter (Garmin P/
N 330-00067-00) can be installed in the VHF COM coax, as close to the COM as
possible. This filter is not required for the GIA transmitter.
If a COM is found to be radiating, the following can be done:
1. Replace or clean the VHF COM rack connector to ensure good coax ground.
2. Place grounding straps between the GIA unit VHF COM and a good ground.
3. Shield the VHF COM wiring harness.
4.7.3.4 Weak COM Receiver
1. Switch GIA1 and GIA2, and reconfigure both GIAs at their new locations, to verify
if the unit or the aircraft wiring is the problem.
2. If the problem follows the unit, replace the GIA.
3. If the problem does not follow the unit, check the COM antenna and cabling for
faults.
4.7.3.5 No COM Sidetone
1. Select the COM SETUP page.
2. Activate any of the following frequencies:
• 118.00 MHz
• 127.00 MHz
• 136.975 MHz
Uncontrolled if Printed
Summary of Contents for Cessna Caravan G1000
Page 2: ...BLANK PAGE Uncontrolled if Printed...
Page 288: ...Uncontrolled if Printed...