Trigger Input
Period Generator
HP 8114A Service Guide
5-5.
Power Supply Voltages on the Timing Board
Apply a 1 MHz squarewave signal with 5 V amplitude, 0 V offset
from a 50 source to the trigger input.
2. At the junction of R313, and R314, or at pin 7 of
a typical
voltage should read 1.75
3. P 10 V trigger input threshold in the
mode
display.
4. Check that at
pin there is a typical voltage of
3.3 and
at
pin 9 a typical voltage of + 1.7 V.
Check for the supply voltages:
1.
pin 1 for + 12 V, and
pin 3 for + 5
2.
pin 2 for -12 and
pin 3 for -5.2 V.
Check the current sources for the period generator:
1. Check pin 3 of
voltage regulator, for 12 V.
2.
Check
pin 2 of
for
3. Varying the frequency from 1.01 MHz to 10.0 MHz the voltage at
pin 1 of
should vary from -0.5 V to -5.0 V.
4. Check for the following voltage drops across R402:
5-6. Voltage Drops Across R402
Delay Generator
Check for the supply voltages:
17502 pin 2 for -12 V, and
pin 3 for -5.2
Check the current sources for the delay generator:
1. Varying the delay from 0.00 ns
to
999 ns the voltage at pin 8 of
should vary as follows:
Troubleshooting 5.13
