12th fret harmonic

Aidan135711

Member
2008-02-10 11:40 am
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.
 

unclejed613

Member
2006-12-28 12:19 am
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 said:

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.

b0_1.JPG
 

Aidan135711

Member
2008-02-10 11:40 am
Re: Re: 12th fret harmonic

sreten said:


A frequency counter is a pointless and expensive complication.

:)/sreten.

b0_1.JPG


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

Member
2006-04-19 1:40 am
Hants
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.guitar/guitarsetup.htm#Setting the pickup height

Here is only one example.
 
The pickup height adjustment is dependent upon the design of the pickup you're using.
Of significant importance is the design of the magnetic field, which is focused to a
specific region above the pickup.

But contrary to manufacturer recommendations, most players with practical experience
using Fender's new "Noiseless Pickups" product line know that they tend to work better
when set lower than the recommended height (spaced futher from the strings). At the
suggested height, most players complain that they sound way too thin - weak sounding.
Lowering the pickup height tends to fatten it up. Maybe the original spec sheets contained
a misprint?
In any case, it's worth experimenting to find out what pickup height works best for your
hardware and tastes.

Just for reference, here is a screenshot of Fender's recommendations for setting up a
Stratocaster.

[IMGDEAD]http://home.swbell.net/deewm/images/Fender.gif[/IMGDEAD]

Fender offers a fairly good selection of setup guides in their support library. They provide a
lot of GENERAL information that is not specifically limited to Fender guitars, as much of the
theory is universal to all guitar types.

Might help to research "Intonation," and "Equal Temperament Tuning" on Google before you
do anything.

Good luck!
 

unclejed613

Member
2006-12-28 12:19 am
also remember that if you change string types (different thicknesses and formulations) you will want to adjust the pickups again, and may have to redo the intonation, since a change in string type brings changes in the string tension, which changes the bow of the neck slightly. that's why a lot of guitarists stick with a certain brand and type of string once they find what they like best. you also want to avoid hanging the guitar on a headstock hook for long periods of time or using a stand that holds the guitar by the headstock, since it can cause the neck to twist. i've seen it happen. if the guitar is going to be stored any length of time, or if its going to be exposed to extreme cold (such as in the cargo hold of an airplane) loosen the strings until they barely start to flop. extreme cold shortens metal, which increases string tension AND truss rod tension and can break the neck