Instead of decision trees, the manual uses numbered steps (e.g., “Check voltage at terminals 2-3. If no voltage, go to step 4…”). A true flowchart would be faster for intermittent problems.
Before drilling holes or running wires, you must understand the physical and electrical limits of the unit as outlined in Section 1 of the manual. Key Technical Ratings
Ensure the installation complies with relevant FAA Advisory Circulars (e.g., AC 43.13-1B and AC 43.13-2A). Gather Materials: You will need the KT 70 transponder Go to product viewer dialog for this item.
To report altitude to Air Traffic Control (ATC), the KT 70 must be connected to an altitude encoder or a digitizing altimeter. The KT 70 supports standard Gilham (Gray) Code input. Gillham Code (Parallel) Wiring Kt 70 Installation Manual
: The unit slides into a tray and is secured with a locking screw on the front bezel. Electrical Interconnect
Fasten the tray to the instrument panel structure using appropriate hardware (typically 6-32 flathead screws).
To report altitude to Air Traffic Control (ATC) in Mode C or Mode S, the KT 70 must be linked to an altitude encoder or encoding altimeter. The manual maps out the standard . Technicians must exercise extreme care when crimping and routing these parallel data lines to avoid data corruption, which causes "ghosting" or incorrect altitude readouts on ATC radar scopes. RF Transmission & Antenna Cabling Instead of decision trees, the manual uses numbered steps (e
Ensure the rear connectors align perfectly with the tray backplate. Forced insertion can bend the fragile connector pins.
The KT 70 must be connected to a gray code encoder for altitude reporting.
Before signing off the installation logbook, execute the following tests using an approved avionics ramp test set (such as an IFR-6000 or equivalent): Before drilling holes or running wires, you must
Must be interfaced with an encoding altimeter or blind encoder to report pressure altitude in AeroElectric 3. System Interconnects
RG-400 or RG-142 double-shielded cable is acceptable.
: Use low-loss coaxial cable (such as RG-400 or better). The manual mandates a maximum allowable signal loss between the transponder chassis and the antenna connector—typically capped at 1.5 dB .
Cause: A broken wire in the Gillham code harness, a misconfigured encoder, or a lack of power to the altitude encoder.