54
MDS 4790M (MPT 1411) I/O Guide
MDS 05-3628A01, Rev. B
Receive
Frequency
This screen is used to display or set the receive frequency. Normally, the radio will
be shipped to the customer programmed with the customer-specified frequency. If
the operating frequency was not specified when the radio was ordered, the RX
frequency is set to the centre of the radio’s operating band. The range of
frequencies for the model are given Section 2.6,
Model Number Codes
, beginning
on page 6.
To change this value, press ENTER, then use the left/right arrow buttons to select
a digit. Then use the up/down arrow buttons to increase or decrease the number.
Press ENTER to make the change.
If the operating frequency is changed more than 5 MHz from the factory setting, the
helical filters must be re-tuned. If the radio is equipped with a duplexer, and the
frequency is changed more than 100 kHz, the duplexer must be re-tuned or
replaced.
Modem
This screen is used to set or display the internal modem speed for compatibility
with the modem in the central host computer.
To change the modem selection, press ENTER, then use the up/down arrow
buttons to display available selections. Press ENTER to make the change.
Baud Rate/Format
This screen is used to set or display the communication attributes for the DATA
INTERFACE port. For a description of the communication attributes, see BAUD
[xxxxx abc] command
, page 31.
To change the baud rate, press ENTER, then press the left arrow button to move
the underscore under the baud rate. Then use the up/down arrow buttons to select
a new baud rate.
To change the data format, press ENTER, then press the right arrow button one or
more times to move the underscore (_) under the character to change. Then use
the up/down arrow buttons to change the character. Repeat for the other
characters in the data format if necessary. Press ENTER to make the change.
Emphasis
This screen is used to enable or disable pre-emphasis and de-emphasis on the
analog input and output signals.
Pre-emphasis is a function used in older analog radios where the modulating signal
is increased (at the transmitter) at the higher frequencies to increase system
performance. De-emphasis compensates (at the receiver) for a signal that has had
pre-emphasis applied.
To enable or disable pre-emphasis and de-emphasis, press ENTER, then use the
up/down arrow buttons to display ENABLED or DISABLED. Press ENTER to make
the change.
Receive Frequency
400.00000 MHz
RX [xxx] command, page 39
Modem
9600M
MODEM [9600M,
MPT1411] command,
page 36
BAUD [xxxxx abc] command,
page 31
Emphasis
enabled
EMP [ON/OFF] command,
page 34
