116
Telemetry Tones and Level Control
The amplitude of individual telemetry tones and CW can be adjusted after the
digital pots levels are properly set. There are no specific commands to make these
changes. The parameters must be changed by directly modifying the parameter
value where it is stored in the serial eeprom.
As an example, lets change the amplitude of the CW ID for link ports. The default
value is 40 in the range of 0 to 255. If the digital pot calibration procedure has been
followed, with a system peak deviatation of 5 kHz, then this tone will have a
deviation of approximately 40/255 * 5 kHz = 784 Hz deviation. Lets say you want to
reduce the level to about 500 Hz deviation. To do that, the value should be
255 * 500/5000 = 25. Lets also say the configuration eeprom address for the link ID
CW amplitude is 192.
To read the current value, use the read eeprom byte command, C107. After entering
an unlock code, you can verify the current value with
C107 192 D
This will return the current CW telemetry level between 0 and 255. To change the
level to 25, use the set eeprom byte command C106.
C106 192 B25 D
The processor will then need to be reset (C000) for the new value to be downloaded
to the Radio Control cards where the ID’s are generated.
C000
Telemetry tone sequence amplitudes are slightly more complicated to adjust. To
change the unkey telemetry “beep-boop” generated upon key up on a repeater port
when there are links active and link delay is on, the “lnkintsnd” parameter needs to
be changed. There are two forms of this parameter in the eeprom, a global default,
which is used to simultaneously set the values for all of the ports, and individual
values for each port.
Within the lnkintsnd parameter, there is a 16 bit integer which is an index into a
table of sound sequences, and an 8 bit integer, which set the tone amplitude. To
change the amplitude for all ports, use the C106 command to set the amplitude part
of the lnkintsnd parameter (address 221 + 2) then issue the set rlnkintsnd command
to transfer this value to all of the individual radio specific values, in rlnkintsnd. To
set this amplitude (default is 127) to 80.
C106 223 B80 D