7.0 RADIO
TRANSMISSION
7.1 Radio
Frequency
Hex
RF
Tx RF
RxRF
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
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
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.
