Re: [sdiy] Tuning indicator

[Don Tillman]

   > From: jhaible at debitel.net
   > Date: Fri, 15 Nov 2002 12:27:14 +0000 (UTC)
   > 
   > I have seen (and built from a kit) something very similar.
   > 
   > I don't remember all the details, but it worked with a counter
   > (4017 ?) 

So only one LED is addressed at a time.  Now that I think about it a
little more, that approach is superior to my proposal of flops
generating 10-phases of square waves.  And simpler.

Yep, that's the way to do it!


   > Date: 15 Nov 2002 16:59:22 -0000
   > From: harrybissell at prodigy.net
   > 
   > we had a different version in the states... but it uses an
   > up/down counter... the guitar gets squared up and causes the
   > counter to go up, the reference makes the counter count down...
   > 
   > when the frequencies are close the LED steps at the beat
   > frequency rate.

But that's no longer a strobe.

Strobes are great because:
  the display does the right thing regardless of the waveform and you
  don't have to worry about accurately triggering off the source.
  
  if the harmonics aren't exact you can see that in the display
  
  tuning is more accurate because the display shows phase instead of
  frequency and you can manually integrate the phase display.

Of course if the source material is a solid VCO waveform and if it
might get tuned over a large range, then your counter approach would
probably be more practical.

  -- Don

-- 
Don Tillman
Palo Alto, California, USA
don at till.com
http://www.till.com