Maintenance
17
Figure 7 Measuring Resistance
1. Turn off the RF power and interlock circuitry.
2. Disconnect the RF line.
3. Connect the multimeter test leads to the center and outer conductor of the
load resistor. Refer to Figure 7.
4. Compare the measured value with the previous measurement and with
the baseline resistance, measured when the load was put into service.
Note:
If the new value differs from either of these by more than 2
ohms this could indicate a failing resistor.
Inspecting the Coolant Level
Coolant lifetime will vary greatly depending on the operating temperature.
z
Heavy Use (full RF power for long times, high ambient temper-
ature, 50 Hz AC supply):
Inspect the coolant every 500 hours.
z
Light Use (fraction of full power, low ambient temperature, 60
Hz AC supply):
Inspect coolant every 2,000 hours.
Note:
Correct any coolant leakage before inspection. (See “Trouble-
shooting” on page 11)
1. Remove the load resistor (Refer to “Load Resistor” on page 18).
2. Inspect the coolant.
z
The coolant should be clear, with a faint yellow tinge, and have a
slightly sweet smell. If it is black with a burnt or acrid smell, drain it
and add about 2.9 gal (11 L) of coolant.
z
With the load still on end, the coolant level should be 4
3
⁄
4
to 5 inches
(125 mm) below the top surface of the resistor assembly mounting
ring, at ambient temperature.
3. Add coolant if necessary.
WARNING
Never attempt to connect or disconnect RF equipment from the
transmission line while RF power is being applied. Leaking RF energy is a
potential health hazard.
WARNING
Disconnect the unit from all power sources before servicing. The unit may
be energized from multiple sources. The potential for electric shock exists.
CAUTION
Use only Bird coolant, P/N 5-1070, to prevent damage to the load.
深圳市新朗普电子科技有限公司
www.xLp17.com Email:[email protected]
TEL:0755-83986300 FAX:0755-88850515
QQ：55178055 285480356
深圳市新朗普电子科技有限公司
www.xLp17.com Email:[email protected]
TEL:0755-83986300 FAX:0755-88850515
QQ：55178055 285480356
