Brian M. Godfrey wrote:
> On making dishes: I made a 24" fiberglass dish a few years ago. It works
> great, but I used to build boats so I made it a little more rugged than I
> needed to so it is heavy. I bought some Kevlar/carbon fiber cloth a year
> ago, intending to put what I'd learned to use and make a super-light one,
> but haven't done so yet.
Have you considered Airex foam and kevlar/carbon? If I can manage to
find a source of the foam I'm planning to try one of those. The foam
will give the dish sound deadening without adding much in the way of
weight. It's formable over a very simple mold using a heat gun. I once
helped a friend build a 56' ketch using Airex. He used fairly thick
material, but it comes down to quite thin. We built a lath frame, and
sewed the panels onto the frame, then a outer layer of fiberglass,
turned the hull over, pulled the lath, and fiberglassed the inside.
By using very lightweight grades of cloth like is used in models and the
foam a parabola should be quite light. I have the cloth, just need to
find a source for the foam in reasonably small quantities.
A 5" focal
> length would put the mic inside the rim of the dish (in a 24" diameter dish)
> and allow for a windscreen to be stretched over the entire dish just like a
> drumhead.
The Rycote wind cover for the Telinga is like this, just a simple circle
of material with elastic in the edges.
One
> nice thing about making your own dish is that you can mess with it, changing
> mics and stuff like that, without trepidation. People who buy finished
> things tend not to fiddle with them - a mistake, in my opinion.
I certainly agree with this. I'm constantly modifying things.
Walt
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