TRP1000-4450 Troposcatter C-Band Outdoor Amplifier
Revision 0
Introduction
1–7
MN-TRP1000-OD
1.4.6.3
Over Drive (excessive RF input level)
As stated in the specifications, the amplifier is guaranteed to deliver at least 60 dBm of power at
the rated output level. Note that 59 dBm is the rated output level where the spectral regrowth will
not exceed -25 dBc. Although the unit may be capable, operating beyond this 60 dBm level is
discouraged. As the input drive level is increased, output saturation will soon be reached where
device currents and temperatures may rise very quickly to disconcerting levels, but without any
effective or visual increase in overall unit output power.
Although the best protection against potentially degrading overdrive conditions is user attention
and vigilance to the input and output levels as mentioned above, Comtech EF Data has
implemented software updates that will help self-protect the unit and warn the user of gross
overdrive conditions. This Overdrive alarm is visible on the Status webpage. The unit begins
adding attenuation at estimated excessive input levels and will eventually declare the visible
alarm when this estimated level is at or above 1.2 dB. If this occurs, the user should reduce input
power until the alarm clears and the estimated overdrive is 0 dB. (Note: Once the alarm is
activated, for hysteresis purposes the input power must be reduced until the estimated overdrive
is 0 before the alarm will clear. This reduction may need to be as much as double the amount of
overdrive because the unit releases attenuation as the input power is decreased). Power Supply
currents are also displayed.
1.4.6.4
Maximum Operating Points
The Status webpage includes the maximum (and in some cases, minimum) operating points of
key parameters as they are recorded by the unit over time. This helps the factory and the user
ensure that the unit is being operated correctly, especially in regards to ambient temperature and
user drive levels.
