Musings on Zeroing in on WWV

[Ron ZL1TW]

Greetings.
               Several times on this Reflector we see posts telling people
to "tune into WWV exactly". Well....if any  readers on the Reflector have
shot hearing like mine that could present a difficulty.
Here is what I do, and I imagine it is close enough for me without
instruments.  I will no doubt be corrected if I have it wrong.
I tune into WWV in CW mode and use the SPOT tone to zero beat with the WWV
tone. Then, if I switch to LSB or USB the announcer should sound the same on
either sideband (ie the pitch of the announcement shouldn't change.)
I guess having USB and LSB sounding the same will also depend on how
accurately the BFO has been set for each sideband.
Just checked my K2 with this method after it has been running the last 5
hours and it shows I am 80hz off frequency... close enough that I won't be
trying to get it any better.
I wonder how close we used to be with the Analog dials we used to use? ( You
*did* use a radio with Analog tuning didn't you?) Turning the clock back
even a bit further, to the days of the homebrew SSB rigs. Remember the band
marker xtal you used,to make sure you stayed in band? How times have changed
when we can build a kitset rig that can stay withing a few hz resolution.
Cheers......Ron ZL1TW






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[Don Wilhelm-3]

Ron,

You are doing it right - even if the BFOs for LSB and USB are severly
misaligned, the voice should still be 'similar' in that the pitch should not
change, although it may sound a bit muffled on one or both sidebands because
the lows (or highs) may not be at the proper amplitude for a good voice
response because they are not inside the passband.

The only caution that I can offer on your CW method is that some folks have
trouble matching the pitch, and also during the times WWV is transmitting a
tone (either 500 or 600 Hz), it is easy to zero on the tone instead of the
carrier - if you find yourself off by 500 or 600 Hz, that may be the
explaination - double check during the minutes when no tone is transmitted.

Since my hearing is shot too, and I don't possess the gift of perfect pitch,
I prefer to use LSB only and look for the tones at the proper pitch with
Spectrogram - you can get within 10 Hz (limit of the K2 dial steps) or
closer with ease - to me that is the easiest and the most accurate, and you
don't have to monkey with calculating the CW offset stuff.

73,
Don W3FPR

> -----Original Message-----
> Greetings.
>                Several times on this Reflector we see posts telling people
> to "tune into WWV exactly". Well....if any  readers on the Reflector have
> shot hearing like mine that could present a difficulty.
> Here is what I do, and I imagine it is close enough for me without
> instruments.  I will no doubt be corrected if I have it wrong.
> I tune into WWV in CW mode and use the SPOT tone to zero beat with the WWV
> tone. Then, if I switch to LSB or USB the announcer should sound
> the same on
> either sideband (ie the pitch of the announcement shouldn't change.)
> I guess having USB and LSB sounding the same will also depend on how
> accurately the BFO has been set for each sideband.
> Just checked my K2 with this method after it has been running the last 5
> hours and it shows I am 80hz off frequency... close enough that I won't be
> trying to get it any better.
> I wonder how close we used to be with the Analog dials we used to
> use? ( You
> *did* use a radio with Analog tuning didn't you?) Turning the clock back
> even a bit further, to the days of the homebrew SSB rigs.
> Remember the band
> marker xtal you used,to make sure you stayed in band? How times
> have changed
> when we can build a kitset rig that can stay withing a few hz resolution.
> Cheers......Ron ZL1TW
>
>

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[Hisashi T Fujinaka]

On Sun, 10 Apr 2005, W3FPR - Don Wilhelm wrote:

> Since my hearing is shot too, and I don't possess the gift of perfect pitch,
> I prefer to use LSB only and look for the tones at the proper pitch with
> Spectrogram - you can get within 10 Hz (limit of the K2 dial steps) or
> closer with ease - to me that is the easiest and the most accurate, and you
> don't have to monkey with calculating the CW offset stuff.

My suggestion requires a second AM receiver and can get you within
fractions of a Hz. You tune the AM RX to WWV and then you zero beat the
background tone on the K2. Since I'm used to it and have extra SW
receivers, it works well. I think either method, once you practice it,
is a lot easier than you'd think!

--
Hisashi T Fujinaka - [hidden email]
BSEE(6/86) + BSChem(3/95) + BAEnglish(8/95) + MSCS(8/03) + $2.50 = latte
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[Ron D'Eau Claire-2]

Don, W3FPR wrote:
The only caution that I can offer on your CW method is that some folks have
trouble matching the pitch, and also during the times WWV is transmitting a
tone (either 500 or 600 Hz), it is easy to zero on the tone instead of the
carrier - if you find yourself off by 500 or 600 Hz, that may be the
explaination - double check during the minutes when no tone is transmitted.

Since my hearing is shot too, and I don't possess the gift of perfect pitch,


--------------------------

The beauty of the Elecraft method is that you do not need to "match pitch"
or have any sense of pitch at all! The Elecraft system uses zero beat
between the signal and the SPOT tone. You just tune for a 'zero' or 'null'.

I have been really surprised at the number of ops who don't seen to be able
to hear the beat note between the signal and the sidetone. The few times I
have actually watched someone who had trouble, they did *not* have the two
tone levels near equal. It's important they be very close to the same
loudness. Then as you approach zero beat, you'll hear the beat note going
slower and slower: "wow,wow, wow..... Wow.......woooow....
Wooooooow............" all you have to do is adjust the frequency until the
"wow" comes to a stop (or very close to it since the K2 tunes in 10 Hz
steps. Indeed, by noting the speed at which the beat occurs between too 10
Hz you can interpolate to estimate the frequency to within only two or three
Hz. For example, the beat goes "wow, wow..." at about 6 time a second at
7,036.00 kHz and goes "wow, wow...wow" about 4 times a second at 7,037.00
kHz, you can be sure the actual frequency is 7,036.006! That can be useful
at times in comparing frequencies.

The bottom line is the tuning method requires *no* ability to hear musical
pitch or match pitches. It only requires the ability to adjust the volume
and sidetone levels properly then adjust the tuning until the third 'beat'
disappears.

Ron AC7AC


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