100-kHz reference frequency. Also, the front IF subassembly (BS) mixes the 4.350-
to 4.449-MHz signal (from subassembly 36) with another oscillator frequency. It,
too, is phase locked to a multiple of the same 100-kHz pulses we have just
From this, another 390-to 399-kHz frequency is developed.
nearly identical but separate frequencies of 390 to 399 kHz (one from the reference
frequency and the other from the VFO output frequency) are compared by a
discriminator in subassembly B5.
If a frequency or phase difference exists, an
error voltage is developed and applied to the VFO (B2).
In each of the following exercises, select the ONE answer that BEST completes
the statement or answers the question.
Indicate your solution by circling the
letter opposite the correct answer in the subcourse booklet.
conversion frequencies needed by a radio set. A secondary function is to
attenuate all noisy frequencies received by the radio set.
provide additional amplification of weak signals when needed.
stabilize all operating frequencies furnished by the synthesizer.
allow both the transmitter and the receiver to operate at the same time.
The output signal of the indirect-class synthesizer is derived from a
combination of crystal oscillators.