Tuning / Frequencies
Before we even begin discussing this complex topic,

QUICK LINKS to Information on HOW TO TUNE
Using an Electronic Tuner
Tuning to EQUAL TEMPERAMENT ('straight up' tuning)
Tuning to JUST INTONATION (beatless tuning)
Tuning to a HYBRID BETWEEN ET and JI - step-by-step for E9/B6*

*the numbers we come up in this section will with work for E9 and C6 as well

(it's not really critical that you understand this stuff - but you may wonder WHY WE TUNE THE WAY WE DO - this begins to explain it).  If you need further explanation, or are just curious, read on . . .
When you play an open string, then play that string at the 5th fret, both the frequency and the pitch went UP (increased).  Every note has a standard frequency which quantifies that note's pitch.  A chart showing which notes vibrate at what frequency is seen by clicking HERE.  Highlighted notes show the twelve E9/B6 universal tuning open notes.  As we learned from the 'how to use a tuner' page, this is somewhat academic since the readout on the tuner is not the frequency of the vibration of the string.  It is how far from the pitch shown on the chart a note is.  

When we tune our guitars to the numbers on the chart, certain notes may sound OUT OF TUNE.  If we play a major scale or, particularly, a major CHORD (e.g., the open 5,4,3 strings), the 3rd note of the scale (3rd string in the example) sounds sharp to most people's ears.  The notes on the chart represent an EQUAL TEMPERED tuning.

QUICK LINKS to Background Information on Tuning
Tuning Your Guitar vs PLAYING IN TUNE
What is Just Intonation and Equal Temperament?
What is a third?  Why is it Important?
Tuning the OPEN E chord
Four Ways to Tune a Pedal Steel Guitar

 Tuning Your Guitar vs PLAYING IN TUNE
This section will explain a bunch of different ways to tune your guitar, so that the open strings and raises and lowers are in tune to one way or the other.  Once you begin to play, many things can change the relative pitch of the notes.  For example, bar pressure, temperature fluctuation, and exact bar placement can determine whether the notes you are playing sound in tune.  THE ABILITY TO PLAY IN TUNE IS ONE OF THE MOST IMPORTANT SKILLS A STEEL GUITARIST CAN POSSESS:  Two important factors determine whether you can play in tune:
Your ears must be able to detect subtle pitch differences and
Your hands must be able to make corrections so that you are in tune, both with yourself AND with the musicians you are playing with.

This is not really an exact science.  THERE IS SOME FLEXIBILITY IN THE EXACT NUMBERS.  GET USED TO THE FACT THAT YOUR PEDAL STEEL WILL NEVER BE PERFECTLY IN TUNE BUT THAT DOESN'T MEAN YOU CAN'T PLAY IN TUNE.  Strings change pitch by simply placing your hands on them.  If you don't believe it, tune your 5th string to B or your 6th string to G# STRAIGHT UP on your tuner. Now rub the string between your thumb and forefinger, moving your fingers from one end to the other of the string 3 or 4 times to warm it up.  Now check the tuner.  SURPRISED????  It can vary enough to make it WAAAAAAY out of tune.  Same can happen in heat or air conditioning or outside in sunlight.  In addition to the heat/expansion effect, once your bar hits the strings a bunch of things can happen.  If it isn't perfectly straight across the strings, the chord will not be in tune.  No matter how perfectly you tune your guitar, it requires constant hand to ear feedback to PLAY it in tune.  Your ear must provide your hands with information on which way to adjust to sound right.  If a steel player doesn't have a good ear and a good understanding of pitch, he/she will never play in tune.  A good musician trains the ear as well as the hands.

 What is Just Intonation; What is Equal Temperament?
There are several ways to mathematically divide up a musical octave, for the purposes of tuning.  One is called JUST INTONATION; another is EQUAL TEMPERAMENT.  EQUAL TEMPERAMENT just splits it up evenly - 12 equal intervals between the notes of an octave.  JUST INTONATION splits it up using fractional parts of the length of the string - half, thirds, fourths.  These don't work out the same as dividing it equally.

The advantage of ET is that everything is equally out of tune (or equally in tune), including both the open chord AND the pedal/lever combinations.  The disadvantage is that your ear may expect certain note combinations (a major triad, for example) to be tuned according to the geometry of the string (something close to JI).  When a string vibrates, there are standing waves you can actually see if you watch a large string vibrate.  It tends to divide the length of the string in half, fourths, thirds, sixths, and other logical fractions of the length.  HOWEVER, if you mathematically divide an octave into equal divisions, these do not coincide with those fractional portions.  THE FRACTIONAL PORTIONS ARE WHAT YOUR EAR WANTS TO HEAR, and are the basis of Just Intonation.  But if you tune perfectly to those fractions (JI) there are combinations of notes that will not sound in tune, even though the open chord you tune to is perfectly tuned.

 What is a third?  Why is it Important?
This refers to the third degree or note of a scale.  Since the pedal steel E9 tuning has three different ways to make a major chord, there are three different thirds.  With no pedals pressed, the open tuning includes an EMajor chord.  The third of that scale is G#.  Another way to play a major chord on E9 is using the A+B pedals.  That gives us an AMajor chord and the third of that scale is C#.  The G# and C# notes should be tuned slightly flat to sound in tune with the other notes of the scale and chord.  For true Just Intonation, they should be about 14 cents flat.  I choose to cut that in half or better.  I usually tune G#'s to -4 and C#'s to somewhere between -4 and -8 cents.  The other major chord is formed by combining the A pedal and the lever that raises the 4th and 8th strings from E to F.  This is a C#Major chord and the third note of that scale is F.  I tune that note 12 cents flat.  Some tuning methods tune that note 26 cents flat.  This is not acceptable for me.  The reason we must pay special attention to thirds is that if you don't tune them slightly flat, the major chord will sound out of tune to your ear.  Otherwise, we could just tune everything straight up ET and it would sound fine.  You may want to do the experiment.  Once you've read through this section try tuning the G#'s, C#'s, and F's straight up to your tuner and listen to the result.  One listening is worth a thousand words.

 Tuning the OPEN E chord
An EMajor chord is E, G#, and B.
I tune E's slightly SHARP to compensate for cabinet drop and, perhaps more importantly, to avoid tuning the 3rds and 6ths TOO FAR FLAT for combinations to work properly without having to fight the tuning by making compromises with the bar - slightly slanting or fretting sharp or flat of the fret mark.   I tune E's `straight up' with the A and B pedals engaged.  I also tune the G# strings (3,6,10) slightly FLAT, usually by 1 Hz or 4 cents.  I tune B's to be in perfect tune with the E's.  
VERY IMPORTANT:  Most people's ears can't really hear 2 or even 4 cents difference.  More than 4 cents may even be difficult to hear in the context of playing a chord.  That's why we can get away with varying our tuning with respect to what the ear expects to hear.  Most people's ears just aren't THAT picky.  As your musical ear improves, you will hear smaller variations and minor tuning flaws will annoy you more.  That's just the nature of the beast.  If you want to learn more about the theory of tuning, go to your favorite Internet search engine and type in `just intonation' `tuning' and/or `equal temperament'.  There's a bunch of information there to read.  It will boggle the mind.

 Four Ways to Tune a Pedal Steel Guitar

#1:  By ear using a tuning fork for reference
If you tune a steel guitar by ear, using a tuning fork to get the open tonic note (E in the case of E9) and striking harmonics at different frets to tune the other open strings and pedal pulls, you will be using a system called `Just Intonation'.  This is a fancy word for what your ear wants to hear.  It sounds great by itself.  The open E Major chord is PERFECTLY in tune to your ear.  But when you hit the A+F position you have to slide your bar ahead almost a third of a fret.  AND you will find several string combinations that require you to `fudge' a little here and there with your bar.  I will not go into detail how to do this, since you can get to the same place by tuning to the Emmons Guitar Company chart referred to below.  Mr. Carl Dixon has authored several posts on the Steel Guitar Forum - http://www.steelguitarforum.com  -- on this topic, with stepwise instructions.  If you click on the `SEARCH' button on the Forum and search for the word `tuning' and the author `C Dixon' you will find more information.

#2:  Tune to a Tuner - all notes `straight up'
Every note is tuned so that the needle on the tuner reads `0' or `straight up.  Once you do this, your guitar will be tuned to a system called `Equal Temperament'.  Another fancy term, ET means that all notes are equally spaced apart within an octave, which is NOT the case with JI.  It will not sound in tune with itself unless you are playing with other instruments tuned to this system (some electronic keyboards are tuned this way)

#3:  Tune to an existing chart
There are several on the Internet
Jeff Newmans is at:  http://jeffran.com/tuning/tuning.htm" http://jeffran.com/tuning/tuning.htm
(E9, C6, and E9/B6U)
The Emmons Guitar Company chart is at http://www.buddyemmons.com/TTChart.htm" http://www.buddyemmons.com/TTChart.htm
(E9 and C6 only)
Most of these charts are pretty close to JUST INTONATION -- ALSO SEE THIS PAGE and THIS PAGE

#4:  Make your own chart, compromising between JI and ET
This is how we will approach tuning on THIS PAGE.  We understand that neither JI nor ET is a perfect system.  In fact, NO TUNING SYSTEM IS PERFECT.  However, our ear can be tricked into thinking that most any system is `in tune'.  In other words, you don't hear any obvious problems.  We will actually tune the E's slightly sharp to avoid tuning the G#'s C#'s and F's SO FAR FLAT that your bar ends up ¼ fret or more off the mark.  NOTE:  if you use the Emmons chart you will tune E's straight up, G#'s 11 cents flat, C#'s 17 cents flat and F's 26 cents flat (you will have to move your bar up more than ¼ of a fret to play the A+F position in tune).  That is exactly why we will tune the E's and B's 4-8 cents SHARP:  so that we won't have to tune the G#, C#, and F notes SO FLAT.  We will arrive at a process for tuning that will allow us to play in tune (within the limits of what our ear can hear) with guitars, keyboards, horns, and other instruments that may be tuned using various tuning systems (ET, JI, or anything in between).