Codan NGT 2010 RF Technical & Service Manual page 222

NGT—Checks and adjustments
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Set up the spectrum analyser as follows:
Centre frequency
Frequency span
Vertical level
Video bandwidth
Sensitivity
Hold down PTT, then adjust the level of the two tones for compression.
Adjust the two tones displayed on the spectrum analyser for equal amplitude by
adjusting the balance control on the two-tone signal generator.
Adjust the sensitivity control on the spectrum analyser to set the two tones at the top
of the screen.
Measure the IMD levels relative to each tone.
Add 6 dB to the reading if referenced to PEP (see
specifications for limits).
If IMD is outside of the specified limits, further analysis is required.
Release PTT.
Check the IMD on the remaining frequencies (see
The centre frequency of the spectrum analyser must be set to the
NOTE
channel frequency selected.
To check for spurious and harmonic components during the IMD
NOTE
checks, adjust the frequency span of the spectrum analyser.
Set to frequency of selected test channel
20 kHz (2 kHz per division)
10 dB per division
300 Hz
Depends on the signal level applied to the spectrum
analyser and requires adjustment when transmitting
NGT Transceiver System Technical Service Manual
page 39, Transmitter
Table 46 on page 156).