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Are you receiving alerts from FSDOs when performing altimeter and transponder checks?

The proliferation of highly sensitive ADS-B ground stations worldwide has created a challenge for Aviation Maintenance Technicians when doing altimeter and transponder checks. Even a small amount of RF leakage can create false intruders and earn you a notice from your FSDO. With a ground station’s sensitivity of -84dBm, even a low power transponder with an radiated power (ERP) of 48dBm can be picked up almost 60 miles away.
VIAVI Antenna Couplers are highly effective at reducing radiated power and provide greater than 20dB of attenuation. However, there are a few things that can be done to further limit RF leakagesuch as:
Using a second antenna coupler for diversity systemsShutting off or using couplers on redundant systems. Keeping hangar doors closed during testing