Tait T850 II Series, Service Manual

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D3.6 T858/859 Initial Adjustment
M850-00
31/09/98 Copyright TEL
3.4 Setting The Output Power
Caution:
If the high temperature shutdown power level has not yet been set or is
unknown, check that the unit does not overheat while setting the out-
put power.
Note 1: Cables and connectors can easily cause a power loss of several watts if either
too long or poorly terminated. Always use the shortest possible leads (or
connectors instead of leads) between the T858/859 and power meter set-up.
Note 2: You will need appropriate extension leads if you wish to carry out the
adjustment procedures with the T858/859 withdrawn from the rack in the
latched position. Alternatively, disconnect and withdraw the T858/859 and
reconnect it behind the rack.
Note 3: The actual power used may be limited by regulatory requirements.
Connect the exciter output to the PA input via a thru-line wattmeter with a 5W
full scale reading. Special BNC/N leads will be required.
Connect an RF power meter to the PA output.
Set RV63 (front panel power control) fully clockwise.
Key on the drive source.
Check that the exciter power is 700mW to 1.3W.
Check that the power output exceeds:
T858 60W
T859 110W.
Adjust RV63 to reduce the power output to the required level (e.g. 50W for T858,
100W for T859).