H805 adapter

[Boli46]

Adapters do exist to match the early threaded horns to the later 3 bolt (287/288) drivers. I have not seen any in some years though, so good luck in finding a pair! I have seen them in both steel and aluminum versions.

Thanks for chiming in, Steve. I was beginning to doubt my senses when nobody else on this forum had heard of these adapters. They do seem to be rather rare though.

On another note. I read in a post of yours many years ago about a wizard in Sidney, Australia who could more or less resurrect any compression driver from the dead. I have an AGA-Baltic 1" driver that is in desperate need of a bit of magic. Do you know if this person is still active and if so, how he could be reached? This driver was connected to an early tar filled H808 horn when I bought it and I would love to hear them playing beautiful music together again, perhaps in an Iconic clone.

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That's more than likely a propitiatory thread size. As a machinist I would first use a thread pitch gauge (like feeler or thickness gauges with different thread pitches on the long edge) to identify how many threads per inch. Next step is to use calipers and measure the minor diameter of the female thread. After that using a machinist handbook one can calculate a very close estimate of the outside diameter of the male thread. At that point a piece of material could be turned and single point threaded in an engine lathe to make a test piece for fit up. This was the kind of stuff I was doing at the age of sixteen. Now you need to find an old guy like me, kids today have never seen a machine shop.
Do you have a trade school near you that teaches the metal trades? Possibly talk to the teacher, maybe for a small donation they could make a project out of it. If your trade schools are anything like the ones left around here, they are always starving for operating funds. Your going to need to supply the material anyway, buy a couple of feet of the stock and leave the rest there. I'd probably use aluminum, grade 6061-T6.

BillWojo

As far as I can tell my horn throat is the standard Lansing 2 1/2" 16 TPI gauge.

I don't know if there is a trade school in my neck of the woods; I will have to investigate.

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+1 about finding a fitting that works with the threads. If you could get something that threads in, and then find some 3 bolt flanges, you could send it all off to someone with machine shop and welding experience to put it together for you.

At least that will get the horns working until the correct adaptors are found

The problem is that even if I could find a fitting with the correct outside threads, it's unlikely that the interior diameter
will be the right one.