PLL FREQUENCY SYNTHESIZER
Most Citizens Band Transceivers in the past used Frequency
Synthesizers utilizing 12 or more quartz crystals to gener-
ate the various radio signals for receiving and transmitting
the assigned CB channels. The frequency stability of each
channel, when receiving or transmitting, was dependent
largely upon the crystals used to generate the frequencies
for that channel. The frequency accuracy and stability of
one channel was often better than another.
Citizens Band transceivers of recent design, such as the
transceiver you have purchased, utilize the most advanced
design of frequency synthesizers called Phase Locked Loop
(PLL) Frequency Synthesizers. These synthesizers utilize
a minimal number of crystals as reference frequencies from
which transmitting and receiving frequencies are developed.
The transmitting and receiving frequencies are stabilized
by phase comparing to the reference frequency and thus pro-
viding a phase-locked loop.
There are several types of PLL circuits in use; the one your
transceiver uses incorporates the best features of these de-
signs. Your transceiver uses crystal controlled standards
with digital type programmable frequency dividers for selec-
tion of the channel frequencies, which are always locked to
the reference frequency. If for any reason the PLL is not
"locked" the transmitter will not transmit.