Technical Manual

Preliminary Release

5.0 User Configuration and Diagnostic Menu

The 2788 uses a simple command line interface for configuring and monitoring key parameters

and metrics. Access is via IP Telnet. The 2788 is set to a default IP address of 192.168.1.128 at

time of shipment. The access is either local, using the Ethernet RJ-45 connector or remote

through the radio system. The command line interface facilitates writing scripts for automated

configuration. Contact Alligator for GUI based software utilities that front-end the Telnet

commands to simplify network management of multiple 2788 radios further .

Should it ever be necessary, an internal push-button resets the IP address to the default of

192.168.1.128 and default Telnet port to 23. The push-button also resets the password,

encryption phrase, and takes the unit out of password mode. The remaining parameters are

unchanged. (See Fig. 3)

5.1 Transmitter Frequency

The transmitter frequency is set in MHz with up to 9 significant figures. The allowed frequency

range is from 757 to 788 MHz. The full format is:

tf=###.######<CR>

The decimal point is optional. Trailing zeros are optional.

Examples: 757<CR> 757.0<CR> 757.1<CR> 757.12<CR> 757123456<CR>

5.2 Receiver Frequency

The receiver frequency is set in MHz with up to 9 significant figures. The allowed frequency

range is from 757 to 788 MHz. The full format is:

rf=###.######<CR>

The decimal point is optional. Trailing zeros are optional.

Examples: 757<CR> 757.0<CR> 757.1<CR> 757.12<CR> 757123456<CR>

5.3 Frequency Calibration

The 2788 frequency reference is a precision TCXO (Temperature Compensated Crystal

Oscillator) that is factory tuned to 1 ppm accuracy. Should it ever be necessary to adjust the

compensation, the following command permits trimming the PLL multiplier that directly affects

the TX and RX frequencies in steps of 1 Hz:

fc=xxxx<CR>

Examples: 100<CR> -100<CR> 10<CR> -10<CR>

Normally calibration is performed by transmitting a CW carrier (dt=1) and monitoring the

output frequency on a calibrated frequency counter.