Check on Communication System
Put the intercom system in emergency mode and set the mode selector on the control box of TKR 128 radio station to“M/RE”(main receiver)position to activate the BIT.The test result will be displayed on the frequency/channel display.If the system works normally,“PASS”will be displayed,followed by the channel number.
Upon completion of the BIT,the radio station works in the displayed channel and noises or audio signals can be heard from the headsets.Set the working channel number based on the flight mission;set the frequency/mode selector at“READOUT”position;set the working frequency and press“SINGLE TONE”button to confirm.Then set the frequency/mode selector back to“PRESET”position and noises or audio signals can be heard from the headsets.
Set the squelch switch to“ON”position and do not operate other selectors.No noises shall be heard.If the system is receiving audio signals,no noises shall be heard during the intervals.Then set the squelch switch to“OFF”position.
Set the mode selector to“D/RE”(dual receivers)position,and the main receiver will be working in the preset mode while the survival receiver is working at the survival frequency and in the mode in correspondence.Noises or voices could be heard from the headsets.
Note:The survival receiver doesn't work in anti-jamming mode.
Set the control box in“M/RE”mode and set the frequency selector at“LIFE”position.Now the main receiver works at the survival frequency in correspondence with the preset frequency.The survival receiver does not work and noises can be heard from the headsets.
Set the control box in“M/RE”mode and set the frequency selector at“PRESET”position.Press“SINGLE TONE”button.The transmitter begins to work and single-tone signals can be heard from the headsets.
Note:Single tone function is not available in anti-jamming mode or when the frequency is between 30-88MHz.
Turn off the control box and the display window extinguishes.Set the frequency selector at“243”position and“243.000”shall be displayed.Now both the main receiver and transmitter are working at 243.000MHz in AM mode.
Set the frequency selector at“PRESET”position and set the control box in“M/RE”position.After the built-in test,press VHF button on the control box of JT-9 Intercom System while pressing the PTT button on the cyclic pitch lever and hold it at the second position.Send audio signals to the radio station working at the specified frequency and the speaker can hear his/her own voice from the headset.Release the PTT button and wait for the response.
After the check,reset the working frequency of the channel that has been operated and change the channel number back to that when the system was last shut down.Then turn off the radio station.Put the control box of the intercom system back to normal mode and reset other switches.