Narco AT-150 Transponder

Product Description

Home > Manuals > Narco AT-150 Transponder > Product Description

1.2 Product Description

The AT 150 TSO consists of a receiver tuned to the frequency of a ground interrogation station (1030 MHz), logic circuitry to check the validity of the received interrogation and encode a reply containing pertinent identification information, and a transmitter which sends the coded reply to the ground station. When an optional altitude digitizer, Narco Model AR-500, is incorporated, coded altitude in- formation will be transmitted to the ground station.

The AT 150 has been designed for 14V operation, therefore a voltage converter, such as Narco Model MP-10, is required when the unit is installed in aircraft with 28 Vdc electrical systems.

The Narco Passive Voltage Converter Kit may be obtained, assembled, and used in place of an MP-10 or KP-15, however, this Converter can only support one (1) AT 150, whose Chassis Lever Code is KC or higher. See Optional Accessory list, Section 1.6 item g.

1.3 Product Specifications


Physical Dimensions and Mounting Refer to appropriate diagram In Section 2.
Weight 2.3 lbs. (1.04 kg)


Power Requirements 13.75 VDC
Receive 1.0 amp
Transmit 1.6 amp
Pilot lamps 0.26 amp


Frequency 1030 MHz
Frequency Stability Crystal Controlled
Sensitivity Minimum trigger level (MTL) -69 to -73 dBm
Side-Lobe Suppression (SLS) 99% or greater for signals from 3 dB to 50 dB above MTL
Dynamic Range Logarithmic pulse response 50 dB or greater above MTL
Bandwidth -60 dB at +-25 MHz

Decoding Capability

Mode A Pulse pair spaced at 8 +-0.5 microsecond
Mode C Pulse pair spaced at. 21 +-0.5 microsecond
Side-Lobe Suppression 35 microsecond suppression upon receipt of two pulses spaced 2 +-0.5 microseconds apart

Encoding Capability

Mode A 4096 reply codes selectable by front panel switches
Mode C Altitude reporting to 30,700 feet
SPIP Special Position Identification Pulse An SPIP may be added to mode A for 20 +-5 seconds


Frequency 1090 MHz
Pulse Power 250 watts peak (Nominal)

External Interference Suppression (Positive)

Pulse Amplitude 5 to 70 volts
Load on Suppressor 3300 ohms

External Interference Suppression (Negative)

Voltage 0.8V (maximum)
Current 5 ma
  Next:  TSO Explanation