Melody Jr Banjolele Intonation problem

I have a Melody Jr Banjolele (15" nut to tailpiece). I set the nut to bridge distance at 13 5/8". Across the strings the octave intonation varies +- 15c. (three bars on my Snark tuner). Is this set-up within a reasonable tolerance for a vintage instrument? Date of Mfr is unknown.

The head has been replaced and the fretwork as well, (frets are in very good condition and nicely dressed but the inlaid dots are plastic and poorly installed.

THe tuning pegs are in good condition and may be original. But they and the plates securing the brackets to the resonator are very dirty an need cleaned. What are your cleaning recommendations?

Thank you.

The actual scale length of an instrument should be theoretical scale length + compensation. The simplest way to calculate theoretical scale length is to accurately measure the distance from the nut to the centre of the 12th fret and double it. This is of course assuming that the nut is accurately placed.

Anyway, a banjo ukulele has a moveable bridge so move it around until the intonation is best. It will likely be on a slight angle with it being shorter for the thinner strings and longer for the thicker strings. The reentrant 4th string is going to be a fly in the ointment. You will have to make some compromises.

EDIT; Oh, you move the saddle away from the nut to flatten the intonation and closer to the nut to sharpen the intonation. You only adjust by tiny amounts at a time and check.

Anthony

Two things to keep an eye on;

1. Make sure the bridge is standing at a right angle to the head. Head stretch with time and humidity changes can cause the bridge to sink and lean changing your scale length, retuning to bring it back up to pitch can cause the bridge to lean even more.

2. Keep the head tight - Damping the strings with my left hand I tap the head (original critter skin) of my little Dixi with my finger nail. I try to keep it in the range of F to A as the uke seems happiest there.

Don't give up, you can get a banjo uke in tune and keep it there, and once you do get it locked it in just remember to mark the head with a pencil so that you can reposition it in the future.