NGT—Technical description (2010)
94 NGT Transceiver System Technical Service Manual
Direct digital synthesis
Local oscillator for upper sideband and lower sideband
IC404 divides the reference oscillator frequency of 44.545 MHz down to the required
456.5 kHz for USB and 453.5 kHz for LSB. These frequencies may vary when different
optional filters are used.
The frequency information is programmed serially from the on-board microprocessor
IC405.
IC405 and IC407 divide the reference oscillator frequency of 14.848333 MHz down to
the required 456.5 kHz for USB and 453.5 kHz for LSB. These frequencies may vary
when different optional filters are used.
The frequency information is programmed serially from the on-board microprocessor
IC408.
Phase lock loop reference
IC403 divides the reference oscillator down to approximately 5 MHz. The signal is
buffered by V411 and is then fed as the reference frequency to IC401.
The reference frequency is varied in small step sizes to produce the 10 Hz steps at the
output of the phase lock loop.
The frequency information is programmed serially from the microprocessor IC405,
based on the channel information.
IC403 divides the reference oscillator down to approximately 5 MHz. The signal is
buffered by V411 and is then fed as the reference frequency to IC401.
The reference frequency is varied in small step sizes to produce the 10 Hz steps at the
output of the phase lock loop.
The frequency information is programmed serially from the microprocessor IC408,
based on the channel information.
ALTERNATIVE TEXT
Drawing 04-03106 (sheet 3)
ALTERNATIVE TEXT
Drawing 04-03378 (sheet 3)
NOTE If the PCB issue status is -06 or earlier, see drawing 04-03378 (sheet 3).
ALTERNATIVE TEXT
Drawing 04-03106 (sheet 3)
ALTERNATIVE TEXT
Drawing 04-03378 (sheet 3)
NOTE If the PCB issue status is -06 or earlier, see drawing 04-03378 (sheet 3).
To Next Page
Loading...
Need help?
General
