[TenTec] Orion II - Tech Topics

[Dr. Gerald N. Johnson]

On Tue, 2006-08-08 at 13:15 -0700, Ron Castro wrote:
> I notice such things...even that net control of the Sunday 20 meter TT net 
> is always 20 Hz low in frequency on his Jupiter!

Are you SURE its not your ear that's tuning 20 Hz off. Have you analyzed
the bass voice harmonics to be certain they come out of your speaker at
3 x the fundamental, not 3 x +/- 20 Hz?

> And I hate it when I'm in 
> a round-table or a net and not everyone is on the same frequency...even 10 
> Hz is noticeable to me.  The Orion's drift about 20 Hz during a warm up 
> period that takes up to three hours (unless you do my fan mod) at 15 MHz 
> WWV, which equates to 40 Hz on 10 meters.  If you're driving a transverter 
> for multi-mode on two meters, that results in 200 Hz drift, which is way 
> into 'Donald Duck' territory!

Nope. The 2m multimode LO isn't derived from the Orion LO so its error
and drift are independent, and probably a couple KHz in error most of
the time because most have independent mixer oscillators not controlled
by the PLL or the master reference.

> 
> Ron N6AHA

-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer