Special Test Connector; Temperature Set Resistor List - HP 5334B Service Manual

b. Crystal and Temperature Set Resistor: The replacement crystal for Y1 is accompanied by the re-
quired temperature set resistor (R20) for the oven. This resistor must be installed with the new crys-
tal. The crystal and R20 can be ordered using HP Part Number 10811-60108. If only the temperature
set resistor (R20) is found to be defective, it must be replaced with the same value and tolerance. If
the resistor (R20) is unreadable, the value required can be determined by finding the oven tempera-
ture value marked on the crystal (Yl). The required resistor can then be determined from Table
8-10. When Y1 is replaced, the nut which secures it to the oven mass should be tightened to a torque
of 0.6 newton-meters (5 in.-lbs). This insures maximum heat transfer without over-stressing the crystal
package.
Table 8-10. Temperature Set Resistor List
c. Oven heater transistors Q7 and Q8: Holding screws for Q7 and Q8 must also be torqued to a specific
force of 0.6 newton-meters (5 in.-lbs.). There are several available pozidriv torquing screwdrivers.
OVEN TEMP "C
80.0
84.0
NOTE
When reinstalling or replacing one or both heater transistors
(Q7
and Q8),
replace both transistor insulators, HP Part Number 0340-0864. This is done
to ensure the temperature stability of the oven crystal due to a balanced
heat transfer to the oven mass from the heater transistors.
RESISTOR VALUE
1.33K
0
8-386. Special Test Connector
PART NUMBER
0698-7239
81 59-0005
8-387. The following paragraphs describe a special connector, shown in Figure 8-8, fabricated for use in
troubleshooting, alignment, and testing of the oven oscillator. The connector provides tlte following:
a. TWO separate input leads for the power to the oscillator circuits and the oven heatcr/controller cir-
cuits.
b. 10-MHz output through a female BNC.
c. Oven monitor output for connection to a voltmeter
d. EFC input connection to ground.
HP 5334B
-
Service Manual
8-55