The material contained in this document is the property of Electronics & Innovation Ltd., it is
subject to change without notice.
February 2007
9
Revision B
input signal in excess of the specified 1 volt rms equivalent to a power level of
13dBm.
This chapter therefore, deals only with certain fundamental procedures for fault
location.
Performance limits quoted are for guidance only and should not be taken for
guaranteed performance specifications unless they are also quoted in the
Specification Section 1.2.
4.2 PERFORMANCE CHECKS
To determine the amplifier’s performance carry out the following procedure.
4.2.1 Initial Check
The following check can be made after repair and adjustments or
whenever the condition of the unit is in question.
a.
Connect AC power supply. Switch on power and observe that the
display initializes.
b.
Connect a sweep generator (HP 8601 or similar) capable of sweeping
the frequency range 10 KHz to 12 MHz, to the input connector.
c.
Adjust the output level of the sweep generator so that a 50 ohm video
detector connected at the output of the unit will not be damaged by
excessive power output. (Reference section 4.4.1 for set up.)
d.
Observe the gain versus frequency ripple on an oscilloscope calibrated
in decibels. The gain variation must be not more than +/- 1.5 dB over
the frequency range.
e.
Connect a calorimetric power meter (HP434 or equivalent) through a
10 dB 200 watt attenuator to the output connector. Adjust the input CW
signal to any frequency between 10 kHz and 12 MHz for 40 watts
output.
f.
Observe the harmonic distortion of the output on a spectrum analyzer.
The harmonic components contributed by the amplifier should be
better than 25 dB down from the fundamental.
(a)
If the above items are found to be outside of the specification, check
the spectral content of the input signal. If this is a pure signal then
the unit needs to be returned to the factory for service.
