Amen Mr Turtle....

@lilley-pad, I would suggest first that you join the Four Equidistant Strings Group here at FOTMD.  Peruse what has already been posted, and if you still have questions, start a new discussion there.

Remember that there are several different ways to tune with 4 equidistant strings, so you need to specify the tuning before anyone can answer your question about chords.

The chart shared by @john-petry is for a chromatic instrument, so I don't know how helpful that will be.

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Dusty T., Northern California
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I don't know the source....might help a bit?

Worth checking out the new book by Mark Tindle. It's specifically on 4-equidistant strings: 

https://tindlemusic.com/products/b103-the-essential-four-string-dulcimer

Howdy kids, just Jon Lilley here again. I have a question. I'm starting to play around with a four string equally spaced setup. My question has to do with how do you do chords with that setup. Any feedback would be appreciated. I have noticed that there are many good books online about using chords, but in the book description it doesn't have four strings equally spaced. as far as I can tell without buying the book. So how do you play chords with equally spaced strings