General Dynamics CG-1220, Operation And Maintenance Manual

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Operation
CG-1220 DTR 4-5
4.2 Main Menu Items
The menus used to support the system interfaces and control system parameters
follow. See Appendix B for a complete Menu Tree.
The following are considered to be the
MAIN MENU
items:

1 - FREQUENCY

2 - INPUT ATTEN

3 - POL SELECT

4 - STATUS

5 - CONFIGS

6 - ACKNOWLEDGE FAULTS

7 - TESTS
4.2.1 FREQUENCY
The [ FREQUENCY] menu allows the user to edit the receiver tuning frequency in
1kHz increments. The valid frequency range depends on the DTR’s conversion
band setup.
While the receiver is under
LOCAL control the editing input source should be either
the keypad interface or the spin-knob. When the receiver is in REMOTE control
(controlled by the data link that is configured as the port in control) frequency
editing is initiated and executed using ASCII M&C commands via the data link.
4.2.2 INPUT ATTEN
[INPUT ATTEN] controls an internal attenuator inside the RF front end. The
attenuator is located after the first amplifier but before the first stage mixer. The
default is 0 dB, but the INPUT ATTEN function may be used to compensate for
overload signal conditions. When using the attenuator, the front panel signal level
reading will automatically compensate so a correct dBm reading is obtained. The
range is 0 to 30 dB in 2 dB steps. Use the scroll knob to scroll through the
available values, 0, 2, 4, …, 30. You must press the ENTER button after a
selection is made to use the new value.