HP 3580A - Mixer Balance Adjustments

Model 3580A
ADJUSTMENT PROCEDURES Section V
g. Store the screen display level by pushing:
DISPLAY ...................... STORE
h. Adjust the signal source for a 40 kHz output (same
level as in Step f ). Reposition the following front panel
controls:
FREQUENCY . . . . . . . . . . . . . . . . . 40.0 kHz
i. Adjust A9C5 (40 kHz + 20 dB AMP ADJ.) for the
same level stored in Step g.
j. Reposition the following front panel controls:
AMPLITUDE REF LEVEL ......... - 20 dB
INPUT SENSITIVITY ............ + 30 dB
(According to MAX
INPUT indicator)
FREQUENCY . . . . . . . . . . . . . . . 01.0 kHz
k. Adjust the signal source to a 1 kHz + 10 dBV
(+ 10 dBm for Option 002) output. (Note the screen
display level by releasing and then depressing:
DISPLAY ...................... STORE).
1. Adjust the signal source for a 40 kHz output (same
level as in Step k). Reposition the following front panel
control:
FREQUENCY ................. 40.0 kHz
m. Adjust A9C6 (40 kHz + 30 dB AMP ADJ.) for the
same level stored in Step k).
5-80. Internal Calibrator Adjustment.
a. Position the following front panel controls: (Only
those controls printed in BOLD require a change from the
previous adjustments).
ADAPTIVE SWEEP ................. OFF
DISPLAY ........ All pushbuttons released
AMPLITUDE MODE ............ 1 dB/DIV
AMPLITUDE REF LEVEL ....... NORMAL
dBv/LIN - dBm 600 .Q ............ dBv/LIN
INPUT SENSITIVITY ............. - 20 dB
VERNIER (Amplitude) ............ CAL
(Fully CW)
FREQUENCY . . . . . . . . . . . . . . . . . 10.0 kHz
START - CTR ..................... CTR
RESOLUTION BANDWIDTH . . . . . . 300 Hz
DISPLAY SMOOTHING ............. MIN
FREQ. SPAN/DIV ............... 0.2 KHz
SWEEP TIME/DIV .............. 0.1 SEC
SWEEP MODE ..................... REP
Option 002: Set dBm 900 .Q/LIN - dBm 600 .Q
switch to dBm 900 .Q; set INPUT MODE
switch to UNBAL.
b. Connect a properly terminated frequency syntehsizer
to the 3580A INPUT and adjust the synthesizer for a
10 kHz - 20 dBV output level (- 20 dBm 900 .Q for instru-
ments with Option 002). See Table 5-14 for proper settings.
c. Adjust front panel CAL 10 KHz for a full scale
(O dB) peak on the display.
d. Reposition the following front panel control:
INPUT SENSITIVITY ............... CAL
e. Remove the input signal source. Adjust A2R5 (CAL
LEVEL ADJ.) for a full scale (0 dB) screen display.
5-81. Mixer Balance Adjustments.
5-82. These adjustments balance the input mixer and
tracking oscillator mixer. These adjustments should be done
if the zero beat response of the instrument under calibra-
tion is too large ( > - 30 dB) or if the TRACKING OSC
OUTput is distorted(> - 40 dB distortion).
5-83. Recommended Test Equipment:
Oscilloscope (-hp- Model 180A with 1801A and 1820A
plug-ins)
a. Disconnect all signal sources from the 3580A.
b. Position the following front panel controls: (Only
those controls printed in BOLD require a change from the
previous adjustments).
ADAPTIVE SWEEP ................. OFF
DISPLAY ........ All pushbuttons released
AMPLITUDE MODE ....... LOG 10 dB/DIV
AMPLITUDE REF LEVEL ....... NORMAL
dBv/LIN - dBm 600 .Q ............ dBv/LIN
INPUT SENSITIVITY ............. - 20 dB
VERNIER(Amplitude) ............ CAL
(Fully CW)
FREQUENCY ................. 00.0 kHz
START- CTR ................... START
RESOLUTION BANDWIDTH . . . . . . 300 Hz
DISPLAY SMOOTHING ............. MIN
FREQ. SPAN/DIV ............... 0.2 KHz
SWEEP TIME/DIV .............. 0.1 SEC
SWEEP MODE ..................... REP
Option 002: Set dBm 900 .Q/LIN - dBm 600 .Q
switch to dBm 900 .Q; set INPUT MODE
switch to UNBAL.
c. Adjust A9Rl (MIXER BALANCE) for a minimum
screen display (less than - 30 dB to meet specifications).
5-25