Installation guide

Troubleshooting
Block Descriptions for Option UNJ and Option 506
1-132
Front Panel Hardkeys, Softkeys, and Keypad
Some front panel keys are referred to as hardkeys; these keys are dedicated to specific functions. Dedicated
hardkeys are used to select the most commonly used features and control the display’s contrast and intensity.
Front panel keys along the display are referred to as softkeys and are used to select functions; these functions
are displayed to the left of each softkey on the display. As softkeys are pressed, their displayed functionality is
executed; some of these softkeys have lower-level menus which are displayed when pressed. The front panel
has a keypad that uses a row and column configuration. Pressing a key on this keypad makes a connection
between a row and column. The row and column information is routed to the A12 CPU where it is interpreted
and the appropriate action is taken.
A2 Display
A Liquid Crystal Display (LCD) provides information about the signal generator’s settings and condition. The
LCD requires a power supply, lighting, and data. The lighting, supplied from a light bulb on the
A2DS1 Display Backlight is powered by the A4 Inverter. The A4 Inverter converts a dc voltage an ac voltage.
Data is generated on the A12 CPU and routed to the LCD through the A3 Front Panel Auxilary Board.
A25 Rear Panel Board
The A24 Line Module, LAN, GPIB, and RS-232 connections are located on
the A25 Rear Panel Board. On signal generators with Option 1EM, the A25 Rear Panel Board is replaced with
the A26 Rear Panel LVDS Board (Option 1EM) and A27 Rear Panel SMB Board (Option 1EM).
RF Output Connector
The RF output connector is a female Type-N. Option 1EM routes the RF output to the signal generator's rear
panel.
RF Path - Frequencies 250 kHz to 4 GHz (Option UNJ)
The output of a YIG oscillator is routed, through the A16 Frac-N, to the A13 Output which contains
ALC circuitry to maintain power leveling. AM and Pulse modulation are also implemented on the A13
Output. The signal is further conditioned and routed through the optional AT1 Attenuator and to the front
panel RF output connector.
For frequencies below 250 MHz, the A13 Output down converts the RF signal. To accomplish the down
conversion, the A18 Reference provides a 1 GHz LO to a mixer on the A13 Output. The resultant IF out of the
mixer is then routed to the AT1 Attenuator or to the front panel RF output connector.
RF Path - Frequencies > 4GHz to ≤ 6 GHz (Option 506 Only)
The output of a YIG oscillator is routed to the A13 Output which contains ALC circuitry to maintain power
leveling. AM and Pulse modulation are also implemented on the A13 Output. The signal is further
conditioned and routed through the A14 Extended Frequency Output (Option 506), to the optional AT1
Attenuator, and then to the front panel RF output connector.
For frequencies > 4GHz and ≤ 6 GHz, the A22 Coupler (Option 506) couples off the YIG oscillator signal and
routes it to the A14 Extended Frequency Output (Option 506) which contains similar circuitry to that of the
A13 Output.
So, depending on the desired frequency, the RF path switches between the A13 Output and the A14 Extended
Frequency Output (Option 506) before it is routed to the optional AT1 Attenuator, and then to the front panel
RF output connector. The RF path is switched on the A14 Extended Frequency Output (Option 506).