Bouchet Bracing Resonances

[Dave M]

I was looking at Courtnall's drawing of one of Bouchet's bracing patterns and was very surprised at the height of the transverse brace under the bridge. It is stated as 14 mm high at the centre, though he doesn't say if it tapers much towards the edges.

This is pretty substantial and I was wondering what effect it would have on the pattern of resonant frequencies one would see on this top. I imagine it would enhance the long dipole, perhaps supress the cross tripole and maybe even reduce the main top monopole a bit. Total supposition on my part. But I wonder if anyone has built using this bracing pattern and looked at the frequency response curve to see what happens...?

D

[North]

I was looking at Courtnall's drawing of one of Bouchet's bracing patterns and was very surprised at the height of the transverse brace under the bridge. It is stated as 14 mm high at the centre, though he doesn't say if it tapers much towards the edges.

Bouchet himself explains in his Cahier p. 44 and 45, that this bar measures 7 mm width and 12 mm height. He also seems to taper the bar quite a lot (down to zero thickness), in a convex shape when viewed along the fan braces.

Unfortunately I have no measurements of the kind you wished. I have not tried the Bouchet bracing yet. Just gathering info about it.

You may however be able to get it from recordings if you find a clear and slow passage without bass strings ringing along.

-north

[Dave M]

Thanks North. Let us know how you get on with this design. Dave