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Re: [TenTec] [Orion] O2 versus Orion

To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Subject: Re: [TenTec] [Orion] O2 versus Orion
From: Robert & Linda McGraw K4TAX <RMcGraw@Blomand.Net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Tue, 10 Jan 2006 07:42:41 -0600
List-post: <mailto:tentec@contesting.com>
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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