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SECTION 5.0
PRINCIPLES OF OPERATION
5.1 PROPER USAGE AND WARNINGS
5.1.1 Controlling Power Output
With a nominal 50 ohm resistive load and an input signal appropriate to produce a power output
within the limitations specified above, the amplifier may be placed in operation. To interrupt the
output, simply interrupt the input signal or increase the input attenuation setting to produce
commensurate output level reduction. The amplifier may be run indefinitely at rated output. Output
power is usually measured with a power meter and suitable power attenuators.
5.1.2 Input Signal Levels
The SMX100 is designed to operate with less than a 0 dBm ( 1.0 mW ) input signal however, to
prevent over driving the amplifier, the Input Protection circuit will activate if the input signal exceeds
3 dBm ( 2.0 mW ) and will automatically compensate for the increased input signal by reducing the
gain of the preamplifier.
It is not advisable to overdrive any amplifier and depend on protection circuits to maintain proper
gain control. IFI makes available with each shipped amplifier, specific amplifier data so the operator
will know the proper input signal levels to more efficiently operate the amplifier. Refer to the test
data sheets information located in Paragraph 4.6 herein.
5.1.3 Sample RF Output Cautions
The SMX100 Sample RF Output connector located on the rear panel must be terminated with the
supplied 50 Ohm load if the output is not being used. Should the SMX100 be operated without a
termination on the Sample RF Output connection, the lack of loading will jeopardize the accuracy of
the metering and output protection; which are based on the Forward Power Readings.
Important Note:
If the amplifier is operated without the 50 Ohm termination, damage to the
amplifier may occur which would void the units warranty.
