Adjusting Low Output Power; Adjusting The Bias Gain - Codan NGT 2010 RF Technical & Service Manual

NGT—Checks and adjustments
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1

Adjusting low output power

Drawing
ALTERNATIVE TEXT
NOTE
NOTE
NOTE
To adjust the low output power:
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1
1
1
1

Adjusting the bias gain

Drawing
ALTERNATIVE TEXT
NOTE
NOTE
To adjust the bias gain:
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1
182
The indicated PEP level with two-tone modulation depends on the type of
measuring instrument, as shown in
Release PTT.
Check that the two-tone waveform is clean and undistorted.
If it is not clean and undistorted, further analysis is required.
08-05416 or 08-05910 (sheet 1)
If the PCB issue status is -04 or earlier, see drawing
Before adjusting the low output power, set the high output power (see
page 180, Adjusting high output
The transceiver must be in Service mode to make this adjustment (see
page 154, Accessing Service
Select any test channel frequency between 4 and 6 MHz (for example, test
channel 16).
Press 7 to select low power.
Proceed as for page 180, Adjusting high output
Adjust LO PWR (R35) for 12 W PEP (5 W on an average reading meter) (see
Figure 33 on page 163
Check that the two-tone waveform is clean and undistorted.
If it is not clean and undistorted, further analysis is required.
08-05415 or 08-05511 (sheet 1)
The bias gain must be set before any intermodulation tests are performed.
The transceiver must be in Service mode to make this adjustment (see
page 154, Accessing Service
Connect a 50 Ω dummy load to the RF connector ( ) (see
Connect a spectrum analyser via a 47 kΩ resistor to the RF connector (see
Figure 43).
This provides a low-level output for the spectrum analyser.
Table 48 on page
power).
mode).
or Figure 34 on page 163
mode).
NGT Transceiver System Technical Service Manual
181.
08-05910 (sheet
power.
and Table 48 on page
Figure 43).
1).
181).