Tune Radio 
    ==========

        The following features are tunable from this screen :-
    
         Carrier Squelch  : The squelch level used when in carrier squelched
                            decode mode.             
    
         Tone Squelch     : The Squelch level used when in tone squelched 
                            decode mode.                          
    
         Volume           : Maximum radio speech volume. 


        The procedure for tuning the two squelch settings is as follows :-

1.  Select the channel with the poorest sensitivity on the radio - Refere to 
    the service manual for details.  Place the squelch decode switch in the 
    Carrier squelch position.
2.  Connect an ac voltmeter to the AC/DC METER position port on the RTX-4005 
    test box.
3.  Set the rf Signal generator to the receive frequency for the selected 
    channel on the radio.  Remove any modulation, reduce the rf output to a 
    minimum and turn the rf off.
4.  Depress the monitor button on the side of the radio and adjust the noise 
    level for 3.2 mV rms.  Note the level on the dB scale, this will be the 
    reference for quieting measurements.
5.  Increase the rf level until squelch break occurs, note the level on the 
    dB scale.  If squelch break occured at between 6 and 12 dB of quieting, 
    proceed directly to step 8, otherwise carry on with step 6.
6.  Press the <+> or <-> keys to set the tone squelch to zero.  Adjust the 
    rf level for 6 dBs of quieting.
7.  At this rf level slowly increase the tone squelch setting until the 
    radio squelches.  This is the tone squelch setting. 
8.  Reduce the rf to its minimum level, and turn off the rf.  The radio 
    should still be squelched, if not repeat 6 and 7.
9.  Use the <Up_arrow> to proceed to the carrier squelch position.
10. Slowly increase the rf level until squelch break occurs, note this 
    quieting level.  If squelch break occured between 8 to 14 dBs of 
    quieting proceed to step 13, otherwise continue with step 11.
11. Adjust the carrier squelch setting to zero using the <-> key.  Adjust 
    the rf level for 8 dB of quieting.
12. At this rf level slowly increase the carrier squelch setting until the 
    radio squelches.  This is the carrier squelch setting. 
13. Use <Esc> to return to the main menu.  If either of the squelch settings 
    needed adjustment program the radio - <F3><F4> from the main menu.


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