Termaline Load Resistor 8745/8746
11
Replacing a Resistive Element
This series of water-cooled loads is designed to be quickly and easily repaired
in the field. If in performing the DC resistance check described previously. A
significant change in resistance is noted, or if for any reason the resistive ele-
ment should fail, inexpensive replacement resistors are available. They can be
installed in the load, using the following procedures:
Removing the Resistor
Note:
Item numbers enclosed in brackets [ ] in the text are so indi-
cated on Figure 2 on page 12 and Figure 3 on page 13.
Note:
Turn off RF Power and interlock circuitry prior to proceeding.
1. Ensure the RF power and water supply are turned off.
2. Disconnect the water hoses at the hose fittings [5] on load.
3. Disconnect the unit from the RF transmission line.
Note:
Do this if the load is not already removed from the system.
4. Completely drain excess water from the load.
5. Set the load on end, with the water connections up.
6. Unscrew the six 114-20 x 2-112 inch socket head cap screws [6] holding
the water chamber [3] to the main load housing.
Note:
Use a 3/16 inch hex Allen wrench.
7. Pull the water chamber assembly (with screws) straight off.
Note:
It may be necessary to rock the chamber gently while care-
fully pulling it off.
The inner flow tube [9] will usually come out with the water chamber assem-
bly, being held to it by the compression of the inner O-ring [4] (water input)
seal. This is normal, and if the resistor body is unbroken, there will be no need
to remove the inner flow tube from water chamber assembly.
The ground cap assembly [10] is fitted tightly within the water chamber and
should normally remain with it. If the inner flow tube has stayed in the resis-
tor section, simply grasp the resistor stop sleeve [7] on the flow tube and pull
out the assembly.
Note:
This includes the cushioning O-Ring [8] which fits loosely
below the stop sleeve - always take care not to lose it by falling off. Also,
if the brass stop sleeve [7] is removed at all, notice that it has a small
escape hole at the side and an access counterbore leading to it.
8. For reassembly, ensure the counterbore is facing toward the O-Ring and
the resistor [1].
Note:
This is essential for internal water venting. Notice the water
output holes and also the small shoulder at the base of the inner flow
tube. At reassembly, this must fit into amating recess in the input fit-
ting at the bottom.
9. Pull the resistor [1], if intact, straight out of the load housing.
Note:
The outer flow tube is captive, and will not come out of the
housing at this stage.
Summary of Contents for TERMALINE 8745 Series
Page 2: ...I am not blank...
Page 12: ...Introduction 2...
