5-5.
20130 LOOP PHASE LOCK, A36, A38, A39, AND A43 (Cont’d)
Equipment
Frequency Counter
HP
5343A
Spectrum Analyzer
HP 8566B
Active Probe
HP 1121A
Probe Power
Supply
HP1122A
Signal Generator
HP 8654A
Low-Voltage
DC Power Supply
HP 6294A
Digital Voltmeter (DVM)
HP 3456A
Function Generator
HP 3325A
BNC to SMB Snap-On Test Cable
HP 85680-60093
Adapter,
SMB Snap-On Male-to-Male
HP 1250-0069
Procedure
PHASE LOCK LOOP 2
NOTE
If PLL2 is phase locked (UNLK annunciator not lit), proceed to step 12. If
the UNLK annunciator is lit, determine if PLL2 (N2) is phase locked as
follows: (a) Press [SHIFT]then [EXT],(b).
Observe ENTRY display and if
N2 is blinking, PLL2 is unlocked. With PLL2 unlocked, proceed to step 1.
If some other oscillator circuit caused the UNLK indication, proceed to
step 12.
1. Position the OUT in test position
as shown in Figure 5-9 with bottom cover removed and allow
one-half hour warm up time. Set LINE switch to STANDBY. Remove A41 PLL2 Phase Detector
from its connector on the motherboard. (It is
not necessary to completely remove the
A41
assem-
bly from the instrument).
2. Set the LINE switch to ON and press [INSTRPRESET].
3. Remove the cable from A40J3 (.15
-
6 MHz OUT FOR AF ~.1
MHz) and connect the Frequency
Counter to A40J3 using a BNC to SMB snap-on test cable.
4.
Press [CW] then enter [3] [0] [MHz] to set the N2 oscillator to 150 MHz.
5. Connect the OVM to A43TP5 (VCO
TUNE) located on top cover of A43.
6. Adjust A40R2 (150 MHz) for a DVM indication of +3.0 Vdc ±0.5Vdc. Refer
to Figure 5-10 for
location of adjustments.
7. Adjust A43R9 (.3 MHz) for a DVM indication of 0.300 MHz
±
0.001 MHz (N2 frequency divided by
500).
8. Press [CW] then enter [1] [9] [.] [9] [9] [9] [9] [9] [9] [MHz]
to set the N2 oscillator to 100 MHz.
9. Adjust A40R4 (100 MHz) for a DVM indication of ±15.0Vdc ±0.5Vdc.
10. Adjust A43R41 (.2 MHz) for a frequency Counter indication of 0.200 MHz
±0.001
MHz (N2 fre-
quency divided by 500).
5-28
Adjustments
HP 8340B/41B
