Marker Checkout, Receiver Sensitivity

Bendix/King

KMA28

Audio Amplifier/Intercom/Marker Beacon Receiver

15.Verify that the audio selector panel system does not adversely affect any other aircraft system by systematically switching the unit on and off, while monitoring the other avionics and electrical equipment on the aircraft.

2.11.1.1Marker Checkout

1.Connect a ramp generator at the antenna end of the marker coax. With the unit under test in HI sensitivity, verify that a 160 ∝ V, modulated 95% with 1300 Hz, signal will illuminate the amber (M) marker light, and that marker audio is present in the head- phones when the Marker Audio (MKR) push-button has been depressed. Select SPR for speaker to verify marker audio availability on the cabin speaker. Verify that the white (A) and blue (O) lights will illuminate within ± 3dB of the amber lamp, with 3000 HZ and 400 Hz applied, respectively.

2.Repeat with the unit in LOW sensitivity, with 430 ∝ Volts applied.

3.Connect the marker antenna and verify proper operation.

2.11.2 Receiver Sensitivity

Although the KMA28 meets FAA TSO-C35d sensitivity specifications, the sensitivity of the receiver has been adjusted to meet real world requirements (150∝ V and 430∝ V, soft). This will usually eliminate the need for the avionics shop to reduce the sensitivity in the field so as to prevent early detection of the marker beacons. If your particular installation requires more or less sensitivity, see adjustment section 2.6, and figure 2-1.

2.12Cellular Interface Checkout

When a wireless telecommunication system is installed and configured, a dial tone will appear in the headset of the pilot when the mic selector is in the “Tel” position. In “ALL” intercom mode, a dial tone will be heard whenever the copilot or passenger’s hook switch is closed.

2.13Final Inspection

Verify that the wiring is bundled away from all controls and no part of the installation in- terferes with aircraft control operation. Move all controls through their full range while examining the installation to see that no mechanical interference exists. Verify that the cables are secured to the aircraft structure in accordance with good practices, with ade- quate strain relief. Ensure that there are no kinks or sharp bends in the cables and coaxial cables. Verify that the cables are not exposed to any sharp edges or rough surfaces, and that all contact points are protected from abrasion.

Complete log book entry, FAA Form 337, weight and balance computation and other documentation as required. Sample text for FAA Form 337, and instructions for continu- ing airworthiness can be found in Appendix D.

Return completed warranty registration application.

006-10565-0000

Page 2-11

Rev. 0, Sept. 2000