Adjusting Balance Control - Codan NGT 2010 RF Technical & Service Manual

Adjusting balance control

Drawing
ALTERNATIVE TEXT
NOTE
To adjust the balance control:
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NGT Transceiver System Technical Service Manual
08-05415 or 08-05511 (sheet 1)
The transceiver must be in Service mode to make this adjustment (see
page 154, Accessing Service
Connect setup as per the bias gain adjustment (see
gain).
Select test channel 21.
Connect the signal generator to provide single-tone audio (1 kHz) via the test unit to:
• the audio input on the 15-way GPIO connector on the junction box or 2012 RF
Unit (see Figure 40 on page
• the 2011 RF Unit via the NGT test handset (see
Set up the spectrum analyser as follows:
Centre frequency
Frequency span
Vertical level
Sensitivity
Hold down PTT, then adjust the single-tone level for compression.
Adjust the sensitivity control on the spectrum analyser to set the tone at the top of
the screen.
Adjust the balance control (R253) for a minimum on 17.2 MHz.
Check that the level of the 2
Release PTT.
mode).
170), or
10 MHz
20 MHz (2 MHz per division)
10 dB per division
Depends on the signal level applied to the spectrum
analyser and requires adjustment when transmitting
nd
harmonic (17.2 MHz) is below 60 dB.
NGT—Checks and adjustments
page 182, Adjusting the bias
Figure 41 on page 170)
185