That shouldn't make a difference, I use a phone app on mine the same way and it is the same readings as the tuners I have. The slot for the melody string may be cut so the string touches on the tuner side of the nut instead of the bridge side, effectively making the distance to the 1st fret longer.
That makes it an interesting mechanical mystery if it has fretwire frets.
Use your tuner, then check the tuning at the 1st fret, if it's not close to what is expected, then probably just tuned. most all tuners available are set up default as equal temper. The space from the zero fret/nut to the 1st fret is usually too big.
Has anyone ever retuned a banjo into mountain dulcimer tuning?
Probably. I would imagine almost every tuning has been tried by somebody. An instrument with 4/5 tuners [or more] could be tuned [with string research] to just about any tuning using some, or all, of the tuners available. Would it be satisfactory? That would be up to the player. I play a 5 string Blue Lion with only 3 strings installed and it is great.
The name applied to the tuning probably depends on which instrument is being discussed.
I wouldn't recommend a heat gun, really high risk of burning the top especially around the sound holes and head/tailstock. Been there, done that. Heat works good when the pieces are pretty much the same thickness, not so much when the are so different
A wide drum sander [panel sander] may work. I've tried leveling wood using a hand held belt sander, doesn't work real well too often.
A 7"-8" long hand plane may give the best results [long up, around 18"/ 20", planes are what the old time cabinet makers used to level or flatten a board].
Like most everything else with a MD, there is not a 'proper' tuning for 4 equidistant, it depends on what you're trying to do. The strings are equally spaced across the nut/bridge, like a 4 string banjo, so they can be picked individually. This layout is used primarily for fingerpicking/flatpicking
FYI- DON"T use the strap to carry the MD like a rifle or purse, over your shoulder, unless you have installed straplocks. The strap could come off the button, allowing the MD to crash and break. I've seen it happen several times to really nice, expensive MDs [not mine, yet].
As far as I know, there is no way to convert guitar tab to dulcimer tab. I think most folks would start with the standard music notation [SMN] and write their own. Doing melody only is fairly easy if you have a little background [FACE, Every Good Boy Does Fine] and know the basics of your MD [tuning, note locations], adding chords [fingerings] etc is harder. Some use a music notation program like TablEdit, MuseScore, or Finale etc.
What's it's current tuning, bass to treble?
Check the fret spacing using a fret calculator.
My Dad fixed tongue [cow] which was then sliced. Had some good haggis and neeps [mashed turnips] in Scotland. Germans have magen [tripe] soup and pickled herring sandwiches. Both are good. Fifty- fifty beer and carbonated lemonade [Germany]. Tried menudo, bleh and cabrito [young goat]. Supreme pizza with anchovies. Alligator and some of the other regional Southern foods, most of which is pretty good [that I've tried]. I'm sure there are more western European dishes I've tried, but it's been 30+ years ago.
Tried Crow a few times, don't like it at all.
You couldl probably make it yourself, which is pretty easy. Just about any hard material will work, a threaded rod, hard wood, hard plastic, corian, etc, as long as you can shape it. Start with a piece 1/4" thick x 3/8" high x 1 3/4" long. The 3/8 will be the fret board to string starting dimension, it should be a bit higher than needed to create a nickel space from the top of the 7th fret to the strings. Taper the length by sanding on the 1/4" surface so one of the 3/8 sides is about 5/16 or so. Use a triangle file or nick the sharp edge on the 3/8 side of the tapered edge for the strings [ match the slots on the nut]. They don't need to be very deep, just enough to locate the strings. The 3/8 side is the one that will face the nut. Sand the bottom [opposite] 1/4 surface, keeping it square, until you get the nickel spacing. I would keep the nickel space on the plus side [about the thickness of a credit card] to allow for string wear-in. Sand the ends to fit the width of the fretboard. Done.
Lisa;
Showing the 'D' like that is a space saver. It would take another staff [bass staff], below to to put it in its proper spot. These two staffs, together, are called a 'grand staff'.
There should be an '8vb' to show that the notes are actually those an octave lower than written.
No need to retune. A 'D' chord in DAD sounds the same as a 'D' chord in any other tuning, the fingering changes when you retune.
Look at it this way, a capo changes the order of the notes available in a tuning. It does not change the notes available in that tuning. Retuning changes the notes available on the instrument. You can prove this to yourself by checking the notes on each string with/without a capo and retuning and do the same thing.
Tuning and note order [capoing] are not particularly relevant to playing chords. They may change the fingering. As long as you have the notes available for a chord, and they are reachable, you can play that chord. Chording is very focused, it is playing 2-3 [or more] notes at a specific point in the tune.
For your own information try writing down the chords you need for each of the songs you will be playing. Then do the same for the chords you can play in the DAD tuning. If all the songs are in D or G, then you need to know the chords D, G, A, C. The notes needed for those are D, F#, A, G, B, C#, E, and C. Note that I only specified notes, not tuning. Find those on your dulcimer, they are all available in DAD. It is acceptable to use only 2 of the three notes of a chord, the first one and the last one [called power chords].
When the capo is used to change the tuning/key it is changing the first, lowest, or root, note of a scale. It is not changing the notes available on the dulcimer.
Just a note, if you have 1+ on your dulcimer, you can play the chords [C, F, G] in key of C. The 1+ adds the C and F in DAD
If you are going to play chords only, no capo is needed. A chord has the same construction regardless of the key of the tune. Actually all the information you need, when there is a vocalist, is the chords and when a chord is played. So having the words with the needed chord just above is sufficient to chord along with the tune. I think it's actually easier that way.
If the music you are looking at shows the chords as
G C G C G D Em D C Em D G C G C G D Em D C,
and the music key is G, play the chords as shown. Your second set of chords is the chords transposed for the key of D, as if you were going to play the melody + chords in the new key of D, not G. You would be playing the chords for a D melody, everyone else would be playing chords for a G melody.
Play the chords either way, which ever sound best or is the most natural feeling. You can play the D as 000, 002, 200, 030, 777, etc or just one note, 0 on the base string [like a standup bass player does, one note at a time]. The G the same, 310, 013 or just a 3 on the base.
Since chords stay the same regardless of the key the song is, you only need to play the chord required by the notation. A 'D' chord is the same all the time. With this in mind, song in 'D', the chords are D, G, and A [which you already know. In 'G' the chords are G, C, and D. You will need to learn to play a 'C'. Song in 'A', the chords are A, D and E. All of these chord cam be played in the DAD tuning [the C is easier with the 1+]. No need to transpose or retune as long as what you're looking at has the chords/key displayed. If a chord is required you don't know or can't play, air strum that chord. For 7ths, use the major, eg., for an A7, play an 'A'. It's one of the benefits chording only, no melody. You can play along in many keys as long as you know how to make the chord called for.
I did one many years ago. Check the fit of the tuner head and check the fretboard for straightness/flatness. Dry fit before gluing. Remember to install the frets before gluing the top on. Don't dent the frets when installing with a hammer [pressing them in is my preference], use a metal spacer after getting them started [I use a metal lathe square cutting bit].
I wonder if the same conversations, etc., occur concerning fretted and fretless banjos.
I did an experiment back when I first added a plus fret and repeated it with my first chromatic MD. I played a couple of tunes on my diatonic, then on the one with the added fret and the chromatic. They all sounded and played the same, by golly [and my other half couldn't tell the difference]. I don't use a noter though, and that can make a bit of difference because of the extra 'bumps/thump's.
I suggest you check the string height first. Try sliding a dime under the strings right next to the 1st fret. It will probably drag or not fit if the slot in the nut has worn a bit. Call the Dulcimer Shop for advice and order another nut also. The bridge should also be checked by sliding a nickel on top of the 7th fret.
The toothpick effectively shortens the VSL.
A starting place for you. The Strothers calculator is on the light side, you can usually go heavier a couple of gauges with no problems.
http://www.strothers.com/string_choice.html
www.stringsbymail.com
Or get individual strings from your local shop. Get 2 of each.
Do you know the string gauge of your strings?
You could try ADDd on the GDDd. the bass string should be ok going up one step to 'A' [give Cedar Creek a call and verify]. It should be compatible with the DAd players then, although chording may be a problem .
That's a pretty broad question. Commercial, for sale, is probably around 19-20". Folkcraft has a travel dulcimer with a 22" VSL. It's possible to make them very short. For example, put a capo on fret 7 on yours. You have effectively created a very short VSL, the capo making the fret a zero fret. Move the capo more towards the bridge and the VSL will get shorter. Playability/tuning not considered.
I have a Blue Lion AJ 5 string. It came with 5 separate strings [5 tuning machines]. The strings were too close together for my fingers so I removed 2 of them and converted it to a 3 string bass which I play when I'm not using the Folkcraft resonator. I've seen 1-2 with doubled bass and melody strings also. I don't think I would use one although they may be great for noter/drone players, more volume probably.
You know what might work? A simple fretboard on a board with a cheap rod piezo pickup on the bridge like those from CBGitty. That's all 'strumsticks' and electric MDs are, basically, just add a small amp. Screw the fretboard to the board, no glue required.
Don;
You can figure out the chords and the notes to each chord using one hand. Here's how; Looking at your left had, palm up, the thumb = the key note name/I chord name, the ring finger = the IV chord and the little finger = the V chord. To determine the notes to a chord, [you need to know the notes in the scale] ; thumb = base/chord name [root] , middle finger = the 2nd or middle note [Major 3rd] ; the little finger = the 3rd or high note [Perfect 5th] . By the way, the other fingers represent the ii, iii, vi, and vii notes/chords. The real challenge is to find the notes on your MD.
Using a 158 tuning, like DAdd, the basic I [D] chord is 0 fret/open; IV [G] chord is 013/310; V [A] chord is 101. These are the same frets to play the I, IV, and V chords in any key using a 158 tuning. You would have to change the tuning to CGC use this for C or AEA for A, etc. You should go the route of previous posts for a more in depth study.
Ken, 158 and 155
@ Pondoro;
Playing on just the melody string is called noter drone or finger dancing. Playing across all three strings is chord/melody. Although the dulcimer is a stringed instrument it is, musically, more like the a standard harmonica [diatonic]. Because of this some things that apply to those other instruments don't work the same on the MD.
Check your messages. [Hover over your name, upper right]
Since you seem to be interested in multiple/double screens, MS pro can do them using 2 tablets via it's 'slave' function. 
A recorder/player would be more useful with that ability I suppose. 
I use MobileSheets Pro on a tablet. It's for Android and Windows. I don't know that it will do all of that but it'a great for music.
A 'medley', [pun intended]. Have a 'medley' party, hand out MD's and play a bunch of tunes one after another, without a break in the music. That's a medley of people with a medley of md's playing a medley of tunes!
That tuner should work just fine. Check the calibration, it should be set to 440.
Maybe one of the folks here will recognize the name and the instrument. In any case it will be fine to learn on. The one thing I can think of that may cause a problem later is it may not be made for equal temperament tuning. As long as you play alone that should not be a problem.
It' looks good to me. There may be a label inside at the lower hearts. The pegs can be adjusted by tightening the screw on the end of the pegs, it won't take much. New strings are probably justified but you can loosen then move the longer of the melody strings to the center position temporarily. Loosen it enough to remove it from the nail on the end and move it over also. The D and A you're looking for are the ones just below middle C. You can find a sound bit of C with a search.
