Posted by Steve C on July 09, 2002 at 22:01:53:
In Reply to: Adding a 5th valve to an Alex F posted by Jeff Baker on July 09, 2002 at 21:18:31:
Jeff,
I just checked the Meinl Weston page and they lable their 45, 46 (no S or SLZ, just 45) and 45H-S rotary F tubas as .728" which converts to 18.4912mm (sounds like 18.5 to me). There Cimbasso also have that same bore size.
Hope that's a good start.
Steve C