    Tune Channel Screen
    ===================

        The following options are tunable from this screen :-

         VCO level        : This field holds the VCO modulation attenuator 
                            level, and controls the deviation associated 
                            with speech signals. 

         Mod level        : This field holds the Ref modulation attenuator 
                            level, and controls the deviation associated 
                            with sub-audio signals, ie PL signalling.


        The procedure for tuning the two squelch settings is as follows :-
    
1.  Terminate the programmer/test cable (RTK-4205A) through a 30dB pad to a
    service monitor (or deviation meter).
2.  Place the meter selector switch on the RTX-4005B test set to the MIC
    position.  Insert a 1 kHz tone at the AUDIO IN port of the test set.
    Use an AC voltmeter to monitor the voltage at the AC/DC METER port
    of the test set.  Using the PTT switch on the RTX-4005B test set to
    key the radio, adjust the level of the 1 kHz tone until 45mV is
    present at the AC/DC METER port.  Dekey the radio.
3.  Set the radio squelch decode switch to the PL position.
4.  Connect the programmer/test cable to the Radio Interface Box(RIB).
5.  If the radio requires a change in frequency or options, make the
    appropriate changes using <F4> from the option screen and reprogram the 
    radio.
6.  Set the channel select buttons on the radio's control top for the
    channel to be adjusted.
7.  Proceed to the Mod. DEV position on the Tune channel screen .
8.  Press and hold down the PTT switch on the RTX-4005B to continuously
    key the radio.
9.  Press the <+> / <-> keys until 4.6 to 4.8 kHz of peak deviation
    is obtained.
10. Release the PTT switch on the RTX-4005B to dekey the radio.
11. Proceed to the Ref. Mod position on the Tuner channel screen.
12. Disconnect the 1 kHz tone from the AUDIO IN port of the RTX-4005B.
13. Press and hold down the PTT switch on the RTX-4005B to continuously
    key the radio.
14. Press the <+> / <-> keys until 0.94 to 0.98 KHz peak deviation is 
    seen
15. Release the PTT switch on the RTX-4005B to dekey the radio.
16. Reconnect the 1 kHz tone to the AUDIO IN port of the RTX-4005B.
17. Repeat steps 7-21 for all the channels to be adjusted.
18. Press F10 to exit from the Tuner menu.  Press 6 in the main menu to
    program the radio.
19. With the 1 kHz tone applied, check the peak devaition.  It should
    be greater than 4.0 kHz but less than 5.0 kHz.	Repeat the
    above procedure if necessary.
20. For channels with transmit PL, remove the 1 kHz tone from the AUDIO IN
    port of the RTX-4005B.  Check the deviation of the PL signal; it should
    be greater than 500 Hz, but less than 1000 Hz.  Repeat the above
    procedure if necessary.

        For further information on key usage or radio communications see 
    help for Radio Alignment, <F2> from main help menu. 
    

