[TenTec] Ten-Tec Rig Comparisons

[Ken Brown]

>  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