Agilent Technologies PSA Series Service Manual page 106

Troubleshooting the RF Section (E4446A, E4447A, E4448A)
RF Section Description (E4446A, E4447A, E4448A)
With the PSA set to a center frequency below 3 GHz, and in zero span,
check that the bias voltages are present. Some of these can be accessed
on the A13J12 Test Connector and some others have test points. With
the negative lead of the DVM on A13J12 pin 6, look for values listed in
the table.
Use care when probing connector pins on A13, especially on A13J8.
CAUTION
Connector spacings are close and shorting nodes can cause damage.
A13TP26/LO_NULL_I_DAC
A13TP27/LO_NULL_Q_DAC
The remaining biases are 2
these are currents they cannot be directly measured at the Lowband
assembly connector. The output of the DAC which controls this ALC
circuit on A13 is A13TP25. To help verify that this part of the circuitry
which drives the Lowband assembly is functioning correctly, perform
the 2
106
Pin/ Name
A13J12 pin1/−5V_F
A13J12 pin2/−5V_M1LO
A13J12 pin3/−5V_M1IF
A13J12 pin4/−5V_M2LO
A13J8 pins 7,8/+3V_LB
A13J8 pin25/+5.2V_LB
A13J8 pin16/+10V_LB
A13TP22/M1LO_ADJ
A13TP23/M1IF_ADJ
A13TP24/M2LO_ADJ
nd
LO Power adjustment.
Nominal Voltage
−5 V
−5 V
−5 V
−5 V
3 V
5.2 V
10 V
100 mV
150 mV
100 mV
−5 to +5 V
−5 to +5 V
nd nd
_LO_PIN and 2 _LO_ATTEN. Since
Chapter 4