I have (2) 18” tenors. One currently tuned to Bb, but has been tuned to C in the past. The other is tuned to C. I have used standard fluorocarbon tenor strings Worth Browns, Oasis Warm and Bright when tuned to C. With Bb, I use heavier Worth. Now I use the equivalent Seaguar leader for both.
My super tenor is a 19" and I initially tuned mine to linear B tuning. Strings used were Fremont Soloist squeakless wound on 4th, Thomastick CF27 on 3rd and Oasis warm florocarbon on 2nd and Ist. I have had it tuned down to Bb with this string set and it still had decent tension and sound. That string set is basically a low G set for GCEA.
I just got a little crazy and installed some Hannabach Silver series medium tension classical guitar strings. I have it tuned one half set up from DGBE (baritone tuning). Sounds great.
A 19" scale instrument will play very well with standard DGBE Baritone strings tuned DGBE. You could try tuning up a semitone if you wanted to yet DGBE is just fine.
A 19" scale instrument will play very well with standard DGBE Baritone strings tuned DGBE. You could try tuning up a semitone if you wanted to yet DGBE is just fine.
On my 18" tenor I have found the best results with the standard Oasis and Worth tenor sets, tuned to Bb. Necessary disclaimer: YMMV, ukuleles and ears differ considerably.