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JBMHS35
Posts: 1
Joined: Jul 03, 2018

by JBMHS35 »

Where do you measure the bore size on your horn? I have a vintage Holton Model 63 Tenor with a dual bore slide. I have never been able to find any of the specs on this horn other that a few vague "I think it's this or that". So, where do you measure the bore size? Thanks.
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BGuttman
Posts: 7368
Joined: Mar 22, 2018

by BGuttman »

If there are soldered-on stockings you can measure the end of the inner slide. Extruded stockings may not be as accurate.

Failing that, you can measure the lower tube at the joint with the bell section.

Best way is a deep reach inside caliper.
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LeTromboniste
Posts: 1634
Joined: Apr 11, 2018

by LeTromboniste »

[quote="BGuttman"]If there are soldered-on stockings you can measure the end of the inner slide. Extruded stockings may not be as accurate.[/quote]

Even with soldered-on stockings, having inner tubes that don't go all the way to the end of the stockings is not uncommon.

You can mesure the outside diameter and substract twice the wall thickness (but then you need to measure the wall thickness which might not be much easier...)
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mrpillow
Posts: 89
Joined: Mar 23, 2018

by mrpillow »

Model 63 should be a dual bore 0.480-0.495" with a 7-1/2" bell.