Operating instructions

LOCAL OPERATION
3-28
The full-scale ranges of the RF power bar chart, are:-
10 mW to 100 kW in 15 steps of 1-3-10 sequence.
100 mV to 3 kV in 16 steps of 1-3-10 sequence.
Directional power measurements
Directional power and VSWR measurements can be made using the optional Directional Power
Head accessory. The
DIRECTIONAL POWER METER screen, accessed by pressing the [Dir Power]
key, is used with these accessories. To leave the
DIRECTIONAL POWER METER display and return
to the Tx test mode display, press the [Tx TEST] key. See Appendix A.
RF harmonic analysis
The harmonic content of a transmitter output can be analyzed using the harmonic analyzer
function.
B3197
Fig. 3-6 Tx power, harmonic analysis screen
To obtain an analysis of a signal, proceed as for making a power level reading. With the power
level of the signal to be analyzed displayed, press the [Harmonc Analys] key. The screen shown
in Fig. 3-6, Tx power, harmonic analysis screen, is displayed. The power level bar chart shows
the power output of the transmitter as before. The harmonic content of the signal is shown on the
HARMONICS bar charts. These four bar charts are each given to progressive harmonics of the
fundamental frequency of the signal. They are graduated in dB relative to the carrier level (dBc),
from 0 to -80 dBc.
The harmonic number and frequency is shown over each active bar chart, with the level, in dBc,
given as a digital read-out.
The level of a harmonic which has a frequency above the RF range of the monitor cannot be
measured and bar charts which would be given to these frequencies remain inactive.
IF passband filters
When making harmonic analysis readings, the IF passband of the Service Monitor can be set
independently to that set in the main
Tx TEST mode. Pressing the [IF Filter] key when the
harmonic analysis function is displayed, allows selection of the following IF passband filters.
300 Hz 3 kHz 30 kHz 300 kHz
The filter selection is retained within the harmonic analysis setup. The IF filter selected in the
main
Tx TEST mode will be unchanged.
For accurate results, the noise floor over the measurement range should be as low as possible, but
the passband should not clip the sidebands of the fundamental signal. Select the filter that will
best suit these requirements.