I can.
73
Bob, K4TAX
----- Original Message -----
From: "John T Gwin" <jtgwin@comcast.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Monday, January 09, 2006 12:13 PM
Subject: Re: [TenTec] [Orion] O2 versus Orion
> Do you guys also calibrate the speedometers
> in your cars to plus or minus 1/10th of 1 percent?
> The more I read on this reflector, the more I can't
> believe I can be satisfied with my 'old' Orion.
>
> -W4SK
> ----- Original Message -----
> From: Robert & Linda McGraw K4TAX
> To: Discussion of Ten-Tec Equipment
> Sent: Monday, January 09, 2006 11:40 AM
> Subject: Re: [TenTec] [Orion] O2 versus Orion
>
>
> My experience tells me that there is a concernable difference in ones
> ability to audibility and accurately "zero beat" a given signal. Unless
> one
> can observe the difference in beat of the two signals via the S-Meter
> fluctuations as the frequency gets very close, it is thus below the audio
> passband of the and certainly below the low frequency hearing of most
> folks.
> Less than 30 to 50 Hz for example. Therefore the 1 Hz resolution or
> ones
> desire to achieve such is of rapidly questionable accuracy.
>
> To this end, I prefer to actually measure the transmitter output or
> actual
> oscillator frequency with a suitable counter capable of measuring to 0.01
> Hz
> at the desired frequency or better. Truthfully, not many hams have
> access
> to such high accuracy items as their cost is several times that of an
> Orion
> II. Thus we do more "referencing" than actually measuring of frequency
> values. In each case, the reference add a percentage of error +/- to the
> resolution method.
>
> I took some time to "practice" various zero beat methods this morning and
> then looked at the actual transmitter frequency. In most cases I was
> able
> to get within 30 to 50 Hz of the desired frequency but certainly in fact
> no
> closer, as the audio passband fell apart below 30 Hz and there was simply
> "nothing to hear" coming out of the receiver. Once I got closer in
> frequency then I was able to detect the swing of the S-Meter and bring
> things in a good bit closer. Still, accuracy of 1 Hz was questionable.
>
> We must remember that these radios are not designed to be frequency
> meters
> or frequency counters and thus the stability and repeatability is very
> questionable when one gets into the single digit Hz region. Then why do
> they put 1 Hz resolution on radios? To be better than the next fellow
> and
> to sell radios with features.
>
> 73
> Bob, K4TAX
>
>
> ----- Original Message -----
> From: "Martin AA6E" <martin.ewing@gmail.com>
> To: "Bill Tippett" <btippett@alum.mit.edu> > standard for WWV comparison.
> >
> > Now that I look at the schematics, I see that the CODEC has a separate
> > "14.360 MHz" clock crystal. Maybe that's the problem. It should be
> > generated from the TCXO. Is that the birdie I hear at 14,351.770?
> > (.05% low) This would introduce a minor offset, which is cancelled
> > out if you calibrate against WWV. Or is there more to it?
> >
> > Orion's accuracy and stability are good, but none too high, IMO. This
> > shows up in netting accuracy at the higher freqs. Of course, 95% of
> > rigs out there are worse. The new IC-7000 has a much better spec:
> > +/- 0.5 ppm vs Orion's +/- 3 ppm. Probably cost them a couple of
> > bucks more. The IC-7800 claims +/-.05 ppm 0-50C "after warmup", for a
> > price.
> >
> > It would be nice if the master oscillator was at least upgradeable or
> > syncable to an external reference, for the few folks who are looking
> > for very high precision.
> >
> > 73 Martin AA6E
> > --
>
>
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