Can anyone in the know explain the possible causes of the fuel gauge needles
jumping whenever a comm radio is transmitting? None of the other instruments
or avionics seem to be affected by this phenomenon. The needles jump up
about 1/3 to 1/2 deflection, even when the radio transmitting is an
independent handheld with no associated wiring in the aircraft.
We understand that the gauges are reacting to RF energy radiated by the
transmitting antennae, but we'd like to understand the possible mechanisms
of this interference and how we can shield the fuel quantity indicator
system to prevent the problem. Would it be as simple as placing a circular
magnet (choke) around the gauge wires, or wrapping the fuel sender unit in a
metallic foil? Shielded cables/wires?
Best Regards,
Larry Graves
AirCrafters Builder Assistance Center
140 Aviation Way, Watsonville, CA 95076
Tel: 831-722-9141 Fax: 831-722-9142
www.AirCraftersLLC.com
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