HP 8340B Manual page 345

8.
Check the voltage level at
the A25 assembly input (A25TP1). The level should
be approximately
9.4V, and not vary.
9.
Attach an oscilloscope or
DVM
to the output of
the X5 amplifier
(A25TP2). The voltage level should
vary
between +0.50
and —1.00V as you vary the front panel knob.
At 0.0 dBm (on the front panel
power
display), the voltage level should be 0.0V, and vary at
a
30
mV/dB
rate.
10. Measure
the voltage at the level meter amplifier output
(A25TP4). The
voltage level should vary
between —3.5 and +5.0V
as you turn the front panel knob.
At 0.0 dBm (on
the front panel power
display), the voltage level should be
0.0V, and vary at
a
200
mV/dB
rate.
11. If any of the A25 assembly voltage levels
are
incorrect,
replace the A25 assembly.
H.22
ALC
Loop
Assembly-Level Troubleshooting
HP 8340B/41B