Emmons Push Pull 4th string issue

[Gerard Rowan]

Hi all, trying to fix a friend's PP, that had E to Eb lowering issue. I notice that the lower finger is coming to its stop at a position considerably further forward position than its neighbours (see pics). This requires more return spring tension to get all the way to the the stop, and that in turn means the string won't lower all the way to Eb, Anyone know why that lower finger is in a different position to the others? Thanks in advance.

[Ian Worley]

The alignment issue in the pics should not affect your ability to lower the string fully as described. Added tension on the lowering finger will make the lever action stiffer, but that should have no effect on the basic function of the lower. The most likely reason for the tuning issue is you just need more slack on the raise side. This is a fairly common issue on string 4 when folks attempt to "tighten up" the C pedal action without understanding some of the basic principles of PP setup.

If there is insufficient slack on the raise, that will stop the lower before it reaches the desired pitch. You'll be able see this if, when you engage the lever, the raise finger follows the lowering finger for a while then stops while the the lowering finger continues to pull farther away, such that the raise finger is no longer in contact with the open tuning screw in the lowering finger. If so you need to loosen the raise collar(s) on that string so the rod moves freely, engage the lower and get it set as it should be. The raise finger should remain in contact with the open tuning screw on the lowering finger at all times except when a raise is engaged. Once you have the lower set correctly, re-set the stop collar with at least that minimum amount of slack, then re-adjust the associated pedal and lever position and travel to get the raises working and feeling as they should.

A push-pull is basically just a pull-release mechanism, the "push" on the lowering finger is just a movable stop with an adjustable return spring to counter the tension of the string on the raise finger. This allows the raise finger to "release" the string tension and lower the pitch. Just like a pull-release, the movement and position of the raise finger is solely what determines pitch on a push-pull, raise or lower. All the lowering finger does is allow the raise finger to move (lower) under string tension by simply moving in that direction when engaged.

As for the lowering finger alignment issue, assuming everything else is set up correctly and the other lowering fingers are all pulled back fully against the opening in the body, it's possible that there is a groove worn in the changer opening of the body at the string 4 position from years of use. A finger groove in the changer opening could potentially cause tuning stability issues though if the finger doesn't rest in it consistently. If so it would require removing the changer to dress the face of the changer opening back to straight line. Hard to know if that's the case without seeing it up close in person, but I did have to do this very repair once on a '73 S10 PP.

[Gerard Rowan]

Thanks very much for the reply Ian. You were quite right - insufficient space on the C pedal raise was the issue - engaging the raise before the lower finger had reached the lowered pitch. Suspect you're also correct about the groove worn in the changer mechanism, but hard to tell without dismantling the entire changer. I've managed to get all changes to work on that string now. Thanks again!