HP 5385A User Manual

HP 5384A and HP 5385A
Service
8-296.
After repairs are made, perform the required
adjustments as described in Section V.
8-297. To troubleshoot the HP 5384A Channel B
input amplifier:
a. Apply a 100 MHz signal at 25 mV rms (70 mV p-
p) to input B.
b. Select Channel B on the counter.
8-298. Referring to the HP 5384A A 1 Schematic
Diagram, Figure 8-50, check for the proper waveform
at A 1 U6(11 ). Refer to Figure 8-46 for the proper
waveform.
8-299. If the proper waveform is not at A1U6(11),
probe the following list of nodes. (Follow the sequ-
ence shown in the list or use the half-splitting
techenique and begin with A 1 US(11).) Referto Figure
8-46,
HP 5384A Channel B Waveforms, for the proper
signal you should observe at each node.
CIRCUIT NODE CIRCUITRY
A1U4B(13)
A1U4B(14)
A1U4A(3)
A1USA(2)
Channel B signal conditioning output
Channel B 2nd gain stage input
Channel B divide-by-4 frequency
divider input
Channel B divide-by-4 frequency
divider output
A1U6A(11) Channel B signal line to MRC
A1U48(13) 0.01 !JS/div.
0.01V/div.
ac coupled
de level is approximately 3.6V
A1U4B(14) 0.01 1-1s/div.
0.05V/div. ac coupled
de level is approximately 3.6V
Figure 8-46. HP 5384A Channel B Waveforms
8-38

HP 5385A Specifications

General

Brand	HP
Model	5385A
Category	Cash Counter
Language	English