The material contained in this document is the property of Electronics & Innovation Ltd., it is
subject to change without notice.
August 2013 Revision B
7
Chapter 4 Maintenance
4.1 INTRODUCTION
The 210L RF amplifier requires no periodic maintenance. The instrument is
unconditionally stable and is fail-safe under all load conditions. Damage can only
be externally caused by the incorrect selection of the AC supply voltage or by an
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
green led illuminates. A brief flash of the fault led is normal at turn on.
b.
Connect a sweep generator (HP 8601 or similar) capable of sweeping
the frequency range 15 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 15 kHz and 12 MHz for 10 watts
output.
f.
Observe the harmonic distortion of the output on a spectrum analyzer.
