12th fret harmonic

[Aidan135711]

Hello everyone
I want to set the intonation on a strat copy I just re-stringed.I know that this can be done by ear,but I find it hard to get perfect.
I am an electronics "nerd" and want to try to use a frequency counter to do this,so what I need to know is this.
How many octaves above the open string is the 12th fret harmonic?
I can get the open string frequency from a table somewhere and by using the freq. counter I think I could get intonation very very accurate.

[Steve Eddy]

Originally posted by Aidan135711
How many octaves above the open string is the 12th fret harmonic?

One.

The frequency at the 12th fret fretted is the same as the harmonic at the 12th fret. Well, assuming your intonation's correct.

se

[Aidan135711]

Thanks for your reply.I assumed wrongly that because the harmonic sound was a bit thinner,it was an octave or two above the note.

[mikecj]

the note of the 12th fret harmonic is 1 octave above the OPEN [unfretted] string. The 12th fret harmonic and the fretted note at the 12th fret are the same octave. A decent electronic guitar tuner will do the job for you just fine.

Mikej

[unclejed613]

first you need to adjust the truss rod so that the fretboard has a very slight concave bow. the middle of the fretboard (just about the 7th or 8th fret) shows about 1/16" clearance when the string is pressed to both the first and last fret at the same time. then the string height is set as low as possible that the string never buzzes when any fret is pressed. the pickup height should be set as high as possible without buzzing against the string when the string is pressed to the last fret.
you want to set your string length so that the frequency of the harmonic and the frequency fretted on the 12th fret are the same. if the fretted note is higher than the harmonic the string is too short, if its lower the string is too long. this is a "quickie" explanation of the process, as some of the adjustments are interactive and parts of the process should be repeated in order until it's just right. the length adjustment detunes the string, and retuning the strings will have a minor effect on the neck bow, which will have an effect on string height, etc... the adjustments become a bit hairier if you have a whammie bar (tremolo bridge) where all of your adjustments are also balanced against spring tension.

once you have done this a few times, you will get the hang of it. if you own only 1 guitar, you won't have to do it very often, maybe once in the summer and once in the winter (humidity changes have an effect on the neck, temperature changes effect mostly the strings).

[Aidan135711]

Thanks Unclejed613,very detailed info there,I will try when I get this little strat re-wired.

[sreten]

Originally posted by Aidan135711

I know that this can be done by ear, but I find it hard to get perfect.

Hi,

As long as the guitar is near proper tuning then the 12th fret and
harmonic are the same note, if you cannot set them together by
ear then some thing is seriously wrong.

A standard guitar tuner with meter is also completely adequate,
and helps understanding which direction the intonation is going.
Use the same setting as the open string.

A frequency counter is a pointless and expensive complication.

/sreten.

[Aidan135711]

Originally posted by sreten


A frequency counter is a pointless and expensive complication.

/sreten.

Yes,I see now that it is,now that I know a tuner(which I dont have) can do this.
I assumed that the tuner only "looked" at the frequency of the open string plus or minus a few Hz.I did not know it had a range of a whole octave or more/string.
Time to buy a tuner.....

[Albertb]

Regarding the height of the pickups, there may be a question about this approach. If the pickup is set too near the strings the magnetic field can damp the strings' vibrations losing sustain. Do a search for guitar setup sites and check out a couple of other approaches to see what alternatives people recommend.

http://mysite.verizon.net/jazz.guita...ickup%20height

Here is only one example.

[unclejed613]

i'm aware of the magnetic damping action, but it's a repeatable starting point. there's a bit of a trade-off between output level and damping, and some pickups have adjustable pole pieces to adjust string-to-string balance as well.