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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