With the OK from b0b and the 'Forum' at large, I respectfully request that this thread be made as a "sticky" for quick reference.
Please note: This is only a tuning guide, not a tutorial for setting up a push/pull.
Tuning an Emmons 'Push/Pull' Guitar:
Keep on pickin'!Glenn Suchan wrote:Sometimes p/p players get confused by the tuning. To make it less confusing let me just say there are three procedures: Open tuning at the key head, endplate tuning, and undercarriage tuning.
To start tuning, note which strings have pitch changes (both raises and lowers). Then check which strings have more than one raise or more than one lower. This is important because only the single greatest raise or lower per string will be tuned using the second or 'endplate' tuning procedure. All other, lesser raises and lowers are tuned by the third or 'undercarriage' tuning. You might want to keep a tuning chart in your pak-a-seat that indicates which adjustments are at the endplate and at the undercarriage. It'll come in handy for "bandstand" tuning adjustments.
NOTE: Most of the time, with a properly adjusted push/pull, tuning at the key head is all you'll need to do. More infrequently, you may have to tune the changer using the other two procedures. For example, if you change the gauge of any string, you WILL have to tune the changer for that string and possibly others. Also, changing brands of strings may require minor tuning adjustments.
1) The First Procedure: If you only need to tune the strings to open pitch (most of the time), the guitar is tuned just like all others; at the tuning keys.
2) The Second Procedure (tuning the changer, or strings and changer with the greatest pitch change) is as follows: First, tune all of the strings to open pitch at the tuning keys (this will give you the starting point by which you'll tune the changer). The second step will be to tune your changer starting with all your greatest raises (I start with pedals 'A', 'B', 'C', etc.). To do this, you'll activate the pedal (or knee lever) for the specific change you wish to tune. **Hint: When I tune pedal 'A' I always depress pedal 'B', too. The reason is, a lot of the time you'll be using both pedals simultaneously, and that will create more cabinet drop than just one pedal (cabinet drop is a form of mechanical pitch drop caused by the depressing of pedals). So, I tune pedal 'A' and pedal 'B' with both pedals depressed, and pedal 'C' with both pedals 'B' and 'C' depressed.** Now, to tune the greatest raises; on the changer endplate there are two rows of holes. Behind those holes are cap screws. These are for tuning the changer. The bottom row (closest to the floor) are for raises, and the top row are for lowers. OK, to tune a raise, depress the pedal to be tuned (pedals 'A' and 'B' for pedal 'A'...); then tune the raise at the tuning key (Don't worry about the fact that you just tuned that string to open pitch. This is where most folks get confused). After you've achieved the correct RAISE pitch at the tuning key, release the pedal(s) and find the bottom hole that lines up with the string you've just tuned for a raise. Using the correct size allen key, turn the cap screw to raise or lower the pitch to the correct OPEN pitch. (Turning counter-clockwise will lower pitch). Re check both raise and open pitches to ensure they're accurate. If not, repeat the procedure until they are correct, then move on to the next change. Do this until all the greatest raised pitches are correct, including knee levers. Next, select a string with greatest pitch lower. A good first choice on your guitar is the knee lever which lowers string four E to Eb. **Hint: When I tune this knee lever I always depress pedal 'B', too, since they are frequently used together** The first thing when tuning a lower is to check and tune the OPEN pitch at the tuning key. Then depress the pedal and or knee lever, locate the TOP row hole on the endplate which corresponds to the string just tuned. Using the allen key, turn the cap screw until the correct LOWER pitch is achieved (Once again, turning counter-clockwise will lower pitch). Re check both lower and open pitches to ensure they're accurate. If not, repeat the procedure until they are correct, then move on to the next change. Do this until all the greatest lower pitches are correct.
3) The Third Procedure (tuning the changer, or strings and changer with the lesser pitch changes): This will require you to locate a 'tuning nut' on the undercarriage. There will be one for each lesser pitch change per string. The most common one is on pedal 'C', for string five. This one isn't a lesser pitch than pedal 'A', string five, but it is subordinate. So, it uses the undercarriage tuning nut. Look at the undercarriage and find the bell crank which raises string five on pedal 'C'. You'll notice a collar on the pull rod which has a small spring and hex nut. This is the 'tuning nut'. Now, the procedure is as follows: Check to make sure all the open strings are tuned correctly at the tuning keys. Then depress the pedal or knee lever with the lesser raise/lower to be tuned. Let's do the 'C' pedal. **Hint: When I tune this pedal I always depress pedal 'B', too, since they are frequently used together** With the pedal(s) depressed reach under the guitar and feel for the 'tuning nut'. This takes practice. Sometimes, I'll look first, put my hand on the tuning nut, then proceed. Anyway, once you've located the correct tuning nut, with the pedal(s) depressed, turn the tuning nut until the correct pitch is achieved. (There is no 'rule-of-thumb' regarding which way to turn the nut to raise or lower pitch. It depends on how it is mounted in relation to the bell crank). Once the pitch is correct, you're good to go, so to speak.
Glenn
) wouldn't be able to handle all the guitars streaming in from around the world, each time they get out of tune. 
) 
