graduated bores of various models B&S rotary F tubas/copies

[Michael Bush]

Tangential comment (sorry):

When John Packer (late to the game) introduced its PT-15 copy, suddenly the Jinbao B&S-style F tuba (previously referred to by many as a PT-10 copy) was referred to by many as as a PT-15 copy.

viewtopic.php?f=4&t=65992#p547713

[DHMTuba]

HI Joe,
My F is a B&S "PERANTUCCI MODEL" (not a PT-10) marked "MADE IN GDR". I think it's mid-1980s vintage (bought it used in 1990).
According to my trusty dial calipers the valve slides measure:
5th = 19mm
1st = 20mm
2nd = 20mm
3rd = 21mm
4th = 21mm
1st and 2nd are definitely the same size, no question. Likewise 3rd and 4th.
Hope this is helpful.

[cjk]

When touting the advantages of his vintage B&S F tuba on tubenet, some bloke used to point out that there were 5 bore sizes vs three.

[TheHatTuba]

Don't remember the specifics, but I remember seeing a Symphonie with a starting bore of 18mm instead of 17mm. Maybe they ran out of 17mm that day.

[Rick Denney]

When touting the advantages of his vintage B&S F tuba on tubenet, some bloke used to point out that there were 5 bore sizes vs three.

Yes. Every PT-10 I've studied had three bores in even millimeters. I don't recall the break points with enough certainty to place a bet, but my recollection is that they just increased the bore of valves smaller than 19mm to 19mm. Thus, the four valves would be 19-19-20-21, and the 5th is also 19mm.

My 6-valve B&S (not a PT, made for the European market the first year after unification) has identical bore sizes to the 5-valve 70's Symphonie I previously owned, right down the line. The five valves on it were 17-18-19-20-21. The sixth valve of the newer instrument, which sits between the 1st and 5th, is 18mm, same as the 1st.

Rick "who always thought the PT-15 had the same valve bore as a PT-10, but a wider bell taper" Denney

[cjk]

I believe that pt10 instruments had a 19mm 5th valve, 21mm 3rd and 4th valves, and 20mm 1st and second valves. 1st and 5th weren't the same.

[thevillagetuba]

HI Joe,
My F is a B&S "PERANTUCCI MODEL" (not a PT-10) marked "MADE IN GDR". I think it's mid-1980s vintage (bought it used in 1990).
According to my trusty dial calipers the valve slides measure:
5th = 19mm
1st = 20mm
2nd = 20mm
3rd = 21mm
4th = 21mm
1st and 2nd are definitely the same size, no question. Likewise 3rd and 4th.
Hope this is helpful.

My B&S "Perantucci Model" is of the same vintage and has the same measurements. I will also see if I can get measurements of the Jinbao clone to see where they fall as it seems you only have measurements for the JP one.

[thevillagetuba]

I just checked the sizes on a Mack 540 (Jinbao) that is one of the older ones and it seemed to follow the same pattern as my Perantucci Model, but slightly smaller. The valves were 5th=18.5, 1st & 2nd=19.5, 3rd & 4th=20.5.

I checked these measurements over and over again, as they were unexpected, and got them consistantly. I want to check another colleagues newer Mack copy to see if it is the same and I'll post what I find.

[thevillagetuba]

I just checked the sizes on a Mack 540 (Jinbao) that is one of the older ones and it seemed to follow the same pattern as my Perantucci Model, but slightly smaller. The valves were 5th=18.5, 1st & 2nd=19.5, 3rd & 4th=20.5.

I checked these measurements over and over again, as they were unexpected, and got them consistantly. I want to check another colleagues newer Mack copy to see if it is the same and I'll post what I find.

Did you measure the inside of the inside slide tubes?
I'm surprised that #4 isn't 21mm

I did. This is an old Mack horn that has a larger shank receiver than the newer ones that are on campus, so I'm not sure what is going on with that horn. I'm still trying to find time to get measurements off of one of the newer ones.

[Tom]

I had a purchased-new-in-1984-by-the-original-owner B&S "Perantucci Model" (GDR, pre-PT 10 designation). I traded that tuba to David Graves in about 2003 (???) for a Rudy Meinl CC tuba while he was teaching at Baylor. I believe he eventually ended up selling it to a student...I do sometimes wonder where it is now.

Anyway, at one time I measured the bore and it was:

5th = 19mm
1st = 20mm
2nd = 20mm
3rd = 21mm
4th = 21mm

In other words, it matched what others here have reported their Perantucci Models to be.

[Michael Bush]

5th = 19mm
1st = 20mm
2nd = 20mm
3rd = 21mm
4th = 21mm

These are the measurements of my newish Mack (actually the very instrument that was for sale in the thread I linked to in my "tangential comment" above).