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If the Valves are vented where are the pinholes?
Posted: Sat Jul 30, 2011 12:41 pm
by thezman
I recently purchased a Tuba with vented valves. Today, I was at a lesson and my teacher asked me where they put the pinholes on the valves; and I havn't had the horn long enough to actually see where they are. So, if the valves are vented, where are the pinholes?
Re: If the slides are vented where are the pinholes?
Posted: Sat Jul 30, 2011 1:11 pm
by Rick F
I think you mean 'vented valves'. If the slides were vented they would leak all the time. If you're talking about vented valves, there is a tiny hole drilled through the valve that matches up to where the slide would be when the piston is at rest — or up.
Re: If the Valves are vented where are the pinholes?
Posted: Sat Jul 30, 2011 1:58 pm
by imperialbari
Re: If the Valves are vented where are the pinholes?
Posted: Sat Jul 30, 2011 5:18 pm
by SousaSaver
Great pic Klaus!
Re: If the Valves are vented where are the pinholes?
Posted: Sat Jul 30, 2011 5:25 pm
by TubaSailor
I see in your signature you have a HB293 -isn't that a rotary horn? If it is, the vent hole will be through the valve casing between the legs of the slide, usually slightly above the middle of the valve (top to bottom) Nice horn -
Re: If the Valves are vented where are the pinholes?
Posted: Sat Jul 30, 2011 7:08 pm
by thezman
Thanks, a HB290 is rotary, the 293 is the same thing but in piston
Re: If the Valves are vented where are the pinholes?
Posted: Sun Jul 31, 2011 4:18 pm
by Rick Denney
Piston valves are vented on the piston, while rotary valves are vented through the casing.
If there are no holes on the pistons across from the valve-tubing port when the piston is not depressed, then the valve is not vented. Do a pop test with the tuning slide to be sure. If you push the slide in and out quickly, you should be able to hear and track the hissing of a vented valve.
Rick "knowing where to look" Denney