Bird Technologies 8320 - Manual (Page 25)

normal operating conditions. As shipped the coolant is at a
factory determined level which should approximately fill the
entire cylindrical radiator tank. Expansion of the heated
coolant is provided for by the expansion reservoir tank. The
vent plug allows the release of excess internal pressure.
However, the loss of up to 10 percent of the full radiator
tank capacity should not impair the operating efficiently of
the attenuator. The coolant should be a clear light yellow
color, if not, it is contaminated and should be replaced. In-
spect occasionally around the clamping bands at the input
and output ends for possible coolant leakage. Tighten the
clamping screw if necessary, and make certain the dia-
phragm and output housing seals are in good condition; i.e.,
soft, pliable and free from surface cracks.
Add Coolant Remove vent plug and add coolant directly into the reservoir
tank. Fill to a depth of only about 1/8 inch in reservoir.
Replace
Coolant
To replace all of the coolant, follow the procedure of para-
graph Coolant and Seals, Disassembly, pertaining to coolant
and seals for Model 8325.
1. Pick up the attenuator and carefully pour out the
coolant into a suitable container. Allow as much
to drip out as possible.
2. Replace the coolant with fresh coolant, filling the
radiator tank to the proper level.
Assembly
RF Load
Resistor
Assembly
(All Models)
To replace the load resistor assembly, use the same proce-
dure as in paragraph Coolant and Seals, Disassembly and
then continue as follows:
1. Carefully pour the coolant into a clean container.
If the coolant is uncontaminated it can be reused,
otherwise discard it.
2. Release the clamping band from the input end as
in paragraph Coolant and Seals, Disassembly.
Disassemble and remove it.
3. The RF section assembly can now be removed
through the input end. Grasp the “QC” connector
and carefully work the assembly free and then
pull it out of the radiator tank. Inspect the input
O-Ring seals, P/N 5-229, for Model 8321 and, P/N
8110-039, for Models 8322, 8323, and 8325, or
signs of deterioration.
Maintenance
15