Adjustments
HF SSB Transceiver 9323/9360/9390/9780 Technical Service Manual 7-31
Transmitter performance checks
Frequency check
Check as detailed on page 7-21, Frequency adjustment.
ALC
q Use the transceiver test unit with the two-tone audio source (700 Hz and
2300 Hz) to modulate the transmitter.
q Increase the audio output slowly, in Transmit mode, until the output power
just ceases to increase (ALC threshold).
q Note the PEP output and increase the audio input by 10 dB.
The increase in output should be less than 0.5 dB above the ALC threshold.
Power output and intermodulation
PA assembly 08-04963, 2 to 26.5 MHz with 100 W PEP selected
Power output should be 100 W PEP at 2 MHz reducing to 85 W at 26.5 MHz (link
X1 soldered on the PA PCB fitted). Intermodulation distortion (using 700 Hz and
2300 Hz two-tone modulation) should be better than −32 dB below PEP (−26 dB
below each tone) as measured with a spectrum analyser (see page 7-26,
Intermodulation).
PA assembly 08-04963, 2 to 26.5 MHz with 125 W PEP selected
Power output should be 125 W PEP at 2 MHz reducing to 85 W at 26.5 MHz
(Link X1 not fitted). Intermodulation distortion (using 700 Hz and 2300 Hz two-
tone modulation) should be better than −32 dB below PEP (−26 dB below each
tone) as measured with a spectrum analyser (see page 7-26, Intermodulation).
PA assembly 08-05237, 2.25 to 30 MHz (1.6 to 30 MHz if option LF fitted)
Power output should be 125 W PEP at 2.25 MHz reducing to 80 W at 30 MHz.
Intermodulation distortion (using 700 Hz and 2300 Hz two-tone modulation)
should be better than −32 dB below PEP (−26 dB below each tone) as measured
with a spectrum analyser (see page 7-26, Intermodulation).
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The indicated PEP level with two-tone modulation will depend upon the type of
measuring instrument used (see Table 7-8).
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