Garmin GNS 480 Installation Manaul

Also see for Apollo CNX80: User Newsletter User Newsletter Supplemental Flight manual Pilot's guide Data list

Contents

Installation ProceduresGNS 480 (CNX80) Installation Manual 560-0982-01 Rev L 2-392.8.11 Time Mark OutputP1-17 Time Mark Out -P1-19 Time Mark Out +The Time Mark Out is a differential output that provides a 1 msec pulse once each second. This timereference is derived from GPS satellites.2.8.12 VHF COMThe GNS 480 provides an internal COM transceiver that can be interfaced to an audio panel or connecteddirectly to a speaker. The PTT input is used to enable the COM MIC audio and cause the COMtransceiver to transmit on the active frequency. Optional external inputs are available to allow the user totoggle the active and standby COM frequencies, and select COM frequencies from a user-definedfrequency list.Refer to Appendix D for interconnect information.Refer to section 3.2.1.5 for information on setting the RF squelch and mic gain values.2.8.12.1 COM Headphone and Speaker Audio OutP4-14 COM Headphone OutP4-6 COM Speaker OutP4-13 COM Audio GroundThe COM Headphone Out is a low-level audio output that is intended to drive a headset or audio panel.This output will provide 280 mW into a 100 Ω load, or 120 mW into a 500 Ω load.The COM Speaker Out is a high-level audio output that is available to drive a speaker. This output willprovide 12 watts into a 4 Ω load, or 8 watts into an 8 Ω load.Both the Headphone and Speaker outputs use the same COM Audio Ground. For normal installations, it isrecommended that the Headphone output be used, and the COM Speaker output be left unconnected.2.8.12.2 COM MIC Audio InP4-8 COM MIC In HighP4-7 COM MIC In LowThe COM MIC input is designed for a standard carbon or dynamic mic with integrated pre-amp providingminimum 70 mv rms into 1000 Ω load. The GNS 480 provides a bias voltage to the microphone.2.8.12.3 Push to Talk (PTT)P4-4 PTTThe PTT is used to enable the COM MIC audio and cause the COM transceiver to transmit on the activefrequency. Refer to section 2.8.9.4 for additional details.2.8.12.4 COM Flip-Flop SwitchP1-14 COM Flip Flop InThe COM Flip-Flop In can be used to toggle the active and standby COM frequencies. Refer to section2.8.9.2 for additional details.