Here the screen width is 80Hz so each horizontal column is a 1 Hz bucket. The FT8 symbol
change event is 2 tones (a frequency change of 12.5 Hz since the FT8 tone spacing is 6.25 Hz.
The scroll rate is sped up the fastest rate, 10 ms per horizontal row (100 frequency measurements
per second).
We see clearly that at the moment the FT8 tone changes, the measured frequency smoothly
changes in the expected way from one tone to the next.
Note that an even smoother transition could be made, by setting the “Minimum samples”
parameter to 240 samples – this would result in slightly lower accuracy measurement but a
smoother transition in tones.
We’re talking here about tradeoffs in different aspects of performance; either way the performance
is excellent and QMX keeps up with the changes in input frequency! So this is a nice confirmation
of the excellent performance characteristics of QMX.
8.7.3 CAT command test
The CAT command test application is a simple screen which allows you to test CAT commands.
An annoying thing about typing CAT commands directly into a terminal emulator when QMX is in
the normal operating mode, is that you cannot see the command you are typing, nor can you edit it
if you made mistakes.
Here in this simple application, you can type the command (or commands) you wish to send to
QMX in the yellow area of the bottom row. If you forget the trailing semicolon, the application adds
one automatically for you. Then simply the command is shown in yellow in the left column, and the
command result in yellow in the right column. When the screen is full, it will scroll automatically.
Naturally unrecognized CAT commands simply return an error ? as per the CAT specification.
QMX operang manual; rmware 1_00_012 81
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