[UK-CONTEST] FT1000MP MkV Shift and Width Controls

[Douglas Maxwell]

Hi all,
    When I look at the manual for the MkV, I always get stuck on the pictorial description of the shift control operation. I think it's wrong. My own method for picturing the action of these controls is the following (frequency increases toward the right):

USB
                                       __________
__________________|___/                   \___ No Shift
                                  __________
__________________|/                   \_____ CCW Shift
                                            __________
__________________|______/                   \ CW Shift


                                       __________
__________________|___/                   \___ No Width
                                            ________
__________________|______/               \___ CCW Width
                                       ________
__________________|___/                \_____ CW Width

LSB
       __________             
___/                   \___|_________________No Shift
 ___________                          
/                   \ _____|________________ CCW Shift
            __________
______/                   \|________________ CW Shift


       __________             
___/                   \___|_________________No Width

          _________             
_____/                \___|_________________CCW Width

       ________            
___/               \_____|_________________CW Width


As can be seen from the above diagrams, in either USB or LSB the action of both controls is constant i.e.
1) The shift control moves the passband in the direction it is rotated.
2) The width control brings in the skirt of the passband it is rotated toward.

Audio frequency is mode dependant, so to get rid of interfering signals it helps me to imagine the following:

LSB                                                   USB
       __________               __________
___/                   \___|___/                   \___
    H                  L           L                 H

Therefore:
USB
1) Higher pitched interfering signals will be above you in frequency.
2) Lower pitched interfering signals will be below you in frequency.
LSB
1) Higher pitched interfering signals will be below you in frequency.
2) Lower pitched interfering signals will be above you in frequency.

With a bit of practice you can now hear the interfering signal and know which way to rotate the shift, width or shift/width controls to effectively eliminate it.

If you need to get rid of interfering signals on both sides.
USB
Both shift and width controls turned CCW.
LSB
Both shift and width controls turned CW.

The effectiveness of the width control is dependant on wither both 2nd and 3rd IF filters are fitted, but with both fitted (and with menu 1-2 shift step = 10Hz) each graduation mark equates to approx 250Hz worth of change. This means that for USB CW with cascaded 500Hz filters and shift and width both CCW by 1 graduation you have almost closed the passband. Try 1/2 graduation mark in this situation for weak signal work and you have an effective 250Hz filter. 

I hope that this will encourage more people to explore their MkV as it is a truly awesome machine when used to the utmost of it's capabilities. I hope it also dispels the myth that you must have a MkV fully loaded to get any performance from it.

P.S. I use the free DX LAB software suite for experimenting, in particular Winwarbler's PSK31 waterfall to observe shift and width effects. Also a lesser known fact, that the C-IV commander software that also comes bundled allows individual control of 2nd and 3rd IF filter insertion. This means with both 500Hz filters installed and with rig control enabled you can choose whether you wish 2nd, 3rd or 2nd and 3rd filters in-line.

Have a Merry Christmas all

Doug
GM0ELP

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