User Manual

Operation RF-Orchestra!™ Transmitter Installation and Operation
5-36 6880493G02-C July 2000
For all Ambient Temperatures falling between the values programmed in parameters 3001
and 3002, the following equation applies, with the assumption that the value stored in
parameter 3002 is greater than that stored in parameter 3001:
CutbackAmount (in dB) = Param3003 * ((CurrentAmbTemp – Param3001)/(Param3002 – Param3001))
Param3001 = Ambient Temperature Power Derate Start (default: +45 C)
Param3002 = Ambient Temperature Power Shutdown (default: +60 C)
Param3003 = Ambient Temperature Derate Maximum Cutback (default: 3.0 dB)
CurrentAmbTemp = Current Ambient Temperature Reading, stored in parameter 1026.
This represents a linear derate from 0 to Param3003 dB, between Param3001 degrees C, and
Param3002 degrees C (See Figure 5-20).
Figure 5-20: Ambient Temperature vs. Power Output Derate Curve
For example, using the default values for parameters 3001, 3002, and 3003, as +45 C, +60C, and
3.0 dB, respectively, we can calculate the amount of cutback that would be present at an
Ambient Temperature of 50 degrees C.
Full Power
3 dB Cutback
(Param 3003)
Shutdown
Ambient Temperature
Power Output
-30C +45C
(Param 3001)
+60C
(Param 3002)