Strings off and I'm looking at the saddle again and it is rather snug in its bridge slot with the pickup wire removed. It's also not a very deep slot, but it's fine w/o the wire. But I see that with the wire in place, the saddle is not very deep in the slot. Maybe just a tad over 1/3 of the total height of the saddle sits in the bridge. I saw in HMS pickup install video, they deepen the slot to compensate for the thickness of the wire. I'm sure the guitar shop that did the installation did not do that. I didn't want to do that myself, but now I'm thinking that I might have to. Just not sure how to approach it. My first thought would be just reduce the saddle (thin it a little so it's looser in the slot) and take some off the bottom.
Yes, do NOT deepen the slot unless it is a last resort, this is very tricky, and unless you have the proper tools with a dremel router jig such as in the Uke Minute #69 with Joe Souza from Kanilea (video and linkey below at end)
OR the following tools from StewMac (
http://www.stewmac.com/Luthier_Tools/Types_of_Tools/Files/Saddle_Slot_Levelers.html) <--I have both of these and have used them to smoothe out the slot, but not appreciably deepen it...
as per advice from both Chuck Moore and as per Frank Ford's instructions on
https://frets.com, you should have a 50/50 balance of the saddle above and below the side of the bridge that faces the nut.
The MiSi pickup ribbon is only about 1.5mm thick and it is FAR EASIER to use some 800 grit sandpaper to take down the BOTTOM of a saddle than it is to alter the depth of the saddle slot in the bridge...
You have to go SLOW, and just a few strokes and then check for 50/50, or thereabouts, depending upon string action at the 12th fret, which ideally should be no lower than 2.65mm otherwise you run the risk of fret buzzing on the first 1-3 frets, especially if you have a wound low G or wound C string which are both thicker and will have a wider arc when the string vibrates, and I've found that if the string is lower, like 2.45mm you either need a VERY light touch when strumming, or are relegated to fingerstyle only in order to avoid fret buzz....
Also, just 1-3 strokes on the face of either side of the saddle (but NOT both sides) when laid flat on the sandpaper, should be enough to make sure there is no binding of the saddle in the bridge slot, be CAREFUL, more than that and you can cause the saddle to SLANT (usually forwards) and this will skew your intonation sharp incrementally and is very hard to compensate for if it is more than 5 cents sharp in the tiny 2-3mm width of the top saddle edge, or aka string break-point of the saddle itself...
All of the above I have dealt with myself on my own and on friends ukes, and while iterative in tiny amounts, you need to do a little at a time, otherwise you will be ordering new saddle blanks and starting over, but not to worry, it's all a learning process, and none of this is fatal if you mess up, but learning to do so is akin to changing a flat tire on your car...
Please let me know if this helps and report back if you need further guidance...
I just want to restate, that one should avoid lowering the depth of the saddle slot in the bridge unless there is no other choice, and usually is because the saddle slot was a short depth to being with, but most of the time there is about 5mm of bridge available on the front-face of the saddle area that is towards the nut.
https://www.youtube.com/watch?v=-Ypj_mhXhss