Anritsu 682XXB - Manual (Page 144)

4. Using the K (male) to 2.4 mm (female) adapter,
connect the Power Sensor to the RF OUTPUT of
the 682XXB/683XXB.
NOTE
Before beginning this calibration proce-
dure, always let the 682XXB/683XXB
warm up for a minimum of one hour.
AM
Calibration
Procedure The following procedure let you (1) adjust the AM
Calibration DAC to provide the correct amount of
AM in both linear (100%/V sensitivity) and log
(25 dB/V sensitivity) modes of operation for frequen-
cies of
£2 GHz and >2 GHz, (2) calibrate the AM Me-
ter circuit, (3) calibrate the AM Function Generator,
and (4) store the results in non-volatile memory
(EEPROM) on the A17 CPU PCB.
NOTE
For those instruments that contain a Down
Converter, the procedure for Linear AM
and Log AM calibration must be performed
twice—once for frequencies
£2 GHz and
once for frequencies >2 GHz. Upon initial
completion of each procedure, the program
will automatically return you to the start to
repeat the procedure.
1. Set up the Function Generator as follows:
a. Mode: EXT
b. Signal: Square Wave
2. Perform Linear AM calibration as follows:
a. At the
$
prompt on the PC screen, type:
calterm 112
and press <ENTER>.
b. Set the function generator output to 0.00 volts.
When done, press any key on the keyboard to
continue calibration.
c. Now, set the function generator to output
±0.50 volts. Use the COMPL button on the
function generator to toggle the output be-
tween +0.50 volts and –0.50 volts.
d. On the computer keyboard, use 1, 2 or 3 to in-
crement and 8, 9 and 0 to decrement the value
of the DAC’s setting to obtain a 9.54 dB differ-
ence in the power meter’s reading when the
function generator’s output is toggled.
4-34 682XXB/683XXB MM
AM
CALIBRATION CALIBRATION
NOTE
For 682X5B/683X5B models, the
procedure for Linear AM and Log
AM calibration must also be per-
formed twice—once for frequencies
of
£2.2 GHz and once for frequencies
of >2.2 GHz.