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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: "gary" <ghoffman@spacetech.com>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Mon, 9 Jan 2006 14:41:24 -0500
List-post: <mailto:tentec@contesting.com>
That's right.

Any piano tuner does this when he tunes your piano.

Gary


----- Original Message ----- 
From: "Carl Moreschi" <n4py@arrl.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Monday, January 09, 2006 12:46 PM
Subject: Re: [TenTec] [Orion] O2 versus Orion


>I can get two tones easily less than one hertz apart by listening to the
> beats as long as the two tones are close in amplitude.  What you actually
> hear is the phase between the two tones gradually changing, not the
> frequency of the beat note.  In this manner you can get much less than 1
> hertz frequency difference.  Try it.  You will see what I mean.
>
> Carl Moreschi N4PY
> 121 Little Bell Drive
> Bell Mountain
> Hays, NC 28635
> ----- Original Message ----- 
> From: "Robert & Linda McGraw K4TAX" <RMcGraw@Blomand.Net>
> To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
> Sent: Monday, January 09, 2006 12:40 PM
> 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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