4-13 FM CALIBRATION Models 682XXB/683XXB with Firmware Versions1.01 to 2.10
Models 682X5B/683X5B with Firmwave Version1.00
This procedure provides the steps necessary to perform FM calibra-
tion. This consists of calibrating the FM Meter circuit, the Offset Bal-
ance DAC, and the FM Gain Control DAC. The FM Gain Control DAC
is calibrated for input sensitivities in both narrow and wide FM
modes.
Equipment
Setup Connect the equipment, shown in Figure 4-11,as
follows:
1. Interface the PC to the 682XXB/683XXB by per-
forming the initial setup procedure, pages 4-7 to
4-12.
2. Connect the 682XXB/683XXB rear panel 10 MHz
REF OUT to the Spectrum Analyzer External Ref-
erence input.
3. Connect the Function Generator Output to the
BNC tee. Connect one leg of the tee to the
682XXB/683XXB front panel FM IN. Connect the
other leg of the tee to the DMM input.

682XXB/683XXB MM 4-37

FM
CALIBRATION CALIBRATION
Serial
I/O

682XXB / 683XXB

COM1
or
COM2

IBM-Compatible PC

Function

Generator

10 MHz
REF OUT
EXT REF
INPUT
RF
IN

Spectrum

Analyzer

OUTPUT
FM
IN RF
OUTPUT

BNC

Tee

INPUT

DMM

Figure 4-11. Equipment Setup for FM Calibration