3. Band C Mixer Diodes
1. Band A Mixer Diodes
a. Coaxial Mixer. Unscrew the base of the coaxial mixer.
a. Disconnect the sub-miniature connectors, remove the
two mounting screws and the mixer assembly.
b. Waveguide Mixers. Unscrew the cap over diode and
CAUTION
replace the-diode. See Fig. 4-18D.
Do not tip or bend the connectors in removing
them. Grasp the body of the connector with the
Oscillator Tube Replacement
fingers or needle nose pliers at the base of the
connector, and pull straight out.
NOTE
A complete oscillator assembly and its sub parts
b. Remove the four screws and spacers that hold the
are listed in the Mechanical Parts section. Replac-
cover and circuit plate to the shell.
ing components such as the oscillator tubes requires
c. Unsolder and replace the diodes with a matched pair.
a complete recalibration with special test equip-
ment and technique. We therefore recommend
See Fig. 4-18A. USE A HEAT SINK WHEN SOLDERING
THE NEW DIODES INTO PLACE, SEE SOLDERING TECH-
replacing the complete assembly and returning the
NIQUE.
defective assembly to your Tektronix Field office
or representative. A calibration procedure is pro-
e. Replace the cover and the mixer assembly. Reconnect
vided in the Calibration section, if it is impractical
the connectors to the mixer assembly.
to return the assembly for repair.
The oscillator tube should only be replace after all tests
2. Band B Mixer Diode
indicate the tube is faulty. Check supply voltages, etc., as
a. Remove the front panel mounting nut and washer.
illustrated in Fig. 4-19A.
b. Slip the mixer assembly back and out of the unit.
1. Band A and B oscillator tube replacement (V40 and V41)
a. Unscrew and remove the screws that hold the tap plate
c. Unscrew the front barrel (1 dB pad) and replace the
to the oscillator chamber. Remove the top plate.
mixer diode. See Fig. 4-18B.
4-13
