HP 5384A Service Manual

r
HP 5384A and HP 5385A
Service
8-291.
OPTION 001 (TCXO). If the HP 5384A/HP
5385A has Option 001 and the oscillator has no output
or a low output, verify that +5 volts is present at C67. If
+5 volts is present at C67, the oscillator module is
defective and must be replaced; it is not repairable.
The correct waveform
for Option 001 (TCXO) is
shown in figure 8-44.
TCXO Signal at Emiter 013
0.5VIdiv.
50 ns/ div .
ac
coupled
figure 8-44. Option 001 (TCXO) Oscillator Waveform
8-292. OPTION 004 OVEN OSCILLATOR. If the HP
5364A/
HP 5385A has Option 004 and the oscillator has
no output or low output, verify that +S volts is present
at LS (probe the lead closest to the rear panel). If +5
volts is present, the oscillator module is defective and
must
be replaced; it is not repairable.
8-293. Input Amplifier Troubleshooting
8-294. To prepare the HP 5384A/ HP 538SA Channel
A
input amplifier for troubleshooting:
a. Apply a 10 MHz signal at 25 mV rms ( 70 mV p·p)
to Input A.
b. Select
FREQ A or PER A on the counter.
c. Use an oscilloscope (and probe) suitable to
display a 10 MHz waveform.
8-36
8-295. Referring to the A 1 schematic diagram in
Figure 8-50 or figure 8-51, check for a waveform at
A 1 U1 (30). Refer to Figure 8-45 for the proper wave-
form. If the proper waveform is not present, probe
the following list of nodes. ( follow the sequence
shown in the
list or use the half-splitting technique
and begin with node A1U38(5).) Refer to figure 8-45,
Channel A Waveforms, for the proper signal you
should observe at each node.
CIRCUIT NODE
A 1C R3 (cathode)
A1U3A(10)
A1U3B ( 5)
A1U3B(2)
A1U6B(14)
A1U1 (30)
CIRCUITRY
Channel A signal conditioning output
Channel A 1st gain stage input
Channel A 2nd gain stage input
Channel A Schmitt trigger input
Channel A Level Translator input
Channel A sig n al line to MRC

HP 5384A Specifications

General

Brand	HP
Model	5384A
Category	Cash Counter
Language	English