7.0RADIO TRANSMISSION
7.1Radio Frequency
Hex | RF | Tx RF | RxRF |
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Channel | Channel | Frequency | Frequency |
| SW5 | SW4 | SW3 | SW2 SW1 |
02H | 1 | 440.825 MHZ | 445.825MHz | ON | ON | ON | ON | OFF |
04H | 2 | 440.850 MHZ | 445.850MHz | ON | ON | ON | OFF | ON |
06H | 3 | 440.875 MHZ | 445.875MHz | ON | ON | ON | OFF | OFF |
08H | 4 | 440.900 MHZ | 445.900MHz | ON | ON | OFF | ON | ON |
0AH | 5 | 440.925 MHZ | 445.925MHz | ON | ON | OFF | ON | OFF |
0CH | 6 | 440.950 MHZ | 445.950MHz | ON | ON | OFF | OFF | ON |
0EH | 7 | 440.975 MHZ | 445.975MHz | ON | ON | OFF | OFF | OFF |
10H | 8 | 440.000 MHZ | 446.000MHz | ON | OFF | ON | ON | ON |
12H | 9 | 440.025 MHZ | 446.025MHz | ON | OFF | ON | ON | OFF |
14H | 10 | 440.050 MHZ | 446.050MHz | ON | OFF | ON | OFF | ON |
16H | 11 | 440.075 MHZ | 446.075MHz | ON | OFF | ON | OFF | OFF |
18H | 12 | 440.100 MHZ | 446.100MHz | ON | OFF | OFF | ON | ON |
1AH | 13 | 440.125 MHZ | 446.125MHz NOT USED FOR TELEMETRY |
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1CH | 14 | 440.150 MHZ | 446.150MHz | ON | OFF | OFF | OFF | ON |
1EH | 15 | 440.175 MHZ | 446.175MHz | ON | OFF | OFF | OFF | OFF |
20H | 16 | 440.200 MHZ | 446.200MHz NOT USED FOR TELEMETRY |
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22H | 17 | 440.225 MHZ | 446.225MHz | OFF | ON | ON | ON | OFF |
7.2.Serial Port Channel Change
The RF channel can be changed by sending an ATX instruction to the serial port when the Address Mode has been selected
ATXn
where n is the Hex Channel Number shown in the table above.
If the menu letter is set to A, then the RF frequency would be set to 458.525MHz when the modem is switched on. This can be modified to say 458.650MHz by sending the following four hexadecimal characters to the serial port:
A | T | X | 0C |
41 | 54 | 58 | 0C |
No more data must be sent to the port for 20mSec while the radio sets the new frequency. CTS will be brought low and then high to indicate the modem is busy.