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hello fellow heliheads and repair guys.
I have an Eb helicon engraved with "the original HOPF" onlu info is from hornucopia
The Hopf family started manufacturing string instruments in Graslitz/Klingenthal area. By 1932, they were making violins, and guitars. In 1948 they fled their homeland and relocated in Taunusstein-Wehen under the name Willy Hopf & Co. They started making woodwinds after relocation. For brass instruments, they stenciled the products of their peers from the former home country. The top line came from Keilwerth. They also stenciled Kuhnl and Hoyer.
Ok the issues
eb in the staff is very sharp open. 2&3 brings it up intune
D is very flat at 2, valves 1&3 bring it intune
low A instead of 12 becomes 13
Bb is 123
false tones are fine
what could cause this problem? what could be the fix, or just live with it
Thanks in advance

I don’t entirely get the OP’s description of the tuning problems, but as far as I do, I think he misinterprets them.

It isn’t the Eb in the staff (the 4th partial) that is sharp. It is the 2nd and 5th partials that are flat.

I assume it is a piston instrument, because the rotor helicons out of the Czech-German tradition can be very good. Whereas I never were a fan of their piston instruments until they started making serious instruments for the American market. Böhm & Meinl being an early representative for that trend.

I once tried an Amati piston BBb sousaphone. I couldn’t make 1st finger C in the staff speak, until it occured to me that it might be very flat. When I still kept only the 1st finger down and aimed for a B natural, then the note spoke.

Klaus

imperialbari It's a rotary. So if you are saying the 2nd and 5th are flat could that mean the horn could be in a=435?

imperialbari wrote:I don’t entirely get the OP’s description of the tuning problems

brassbow wrote:hello fellow heliheads and repair guys.
eb in the staff is very sharp open. 2&3 brings it up intune
D is very flat at 2, valves 1&3 bring it intune
low A instead of 12 becomes 13
Bb is 123

The part in red is the one that stands out for me. I can't think of any register in which I'd expect 12 to work for A. I'd use 1 (3rd partial) or 123 (2nd partial.)

The part in purple is just a little ambiguous, since we will ordinarily play a D that way on 2nd or 4th partials. I guess you mean the 4th, and you're going to the 5th with 1_3, which adds up and fits the context.

While I'm not sure it makes sense to me that anyone would make A=435Hz tubas in the time frame you describe (it isn't clear when they started brass production, but apparently it was strings before WWII), Klaus is sure right that you can expect trouble if you're tuning to the 5th partial. The usual alternate explanation for overall flat pitch seems to be "leaks", but I'm sure there are other possibilities.

I haven’t heard of German instruments built to any lower standard than A=440Hz since 1920.

The causes for the random pitch pattern could be leaks or inner obstructions. I would put it in a bathtub and flush it through from the leadpipe end. Hot water.

Photos please.

Klaus