The Omni V and VI use a UHF synthesizer divided down
to 5 MHz for the PTO and crystals for the band selects but only include
band pass filters for ham bands. No continuous coverage provisions.
Jerry you're right about all you said. In addition to what you said:
The Omni VI (and maybe V) use crystals for the band selects, yet those
crystal oscillators are phase locked to the 10 MHz reference oscillator
(or is it 20 MHz?). The PLL system is carefully designed to minimize
phase noise, probably having low loop gain, narrow bandwidth and long
time constants. This is why sometimes when switching to some bands (like
30 meters) you can hear the band select oscillator take a little while
to get locked to the reference. The phase noise of that system is very
low for a phase locked loop oscillator, yet higher than just a plain
crystal oscillator can be.
Does the Omni VI not have as many bandpass filters as the Paragon, and
are they narrower than the Paragon's? Maybe, and that may be part of why
it can't do continuous coverage. Another reason is not enough crystals
in the band select oscillator, where the Paragon uses a PLL, without
crystals, that can cover all of the needed frequencies.
The synthesizer divided down to make the 5 MHz VFO is a VCXO not a PTO.
The only permeablility tuned oscillators are in the band select
oscillators, and those are only tuned to get the crystal oscillators
locking to the reference right. Permeability tuning is not used as the
variable while you are turning the VFO knob.
DE N6KB
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