Some 4J observations

[roweenie]

Ever since I was a teenager, I've wanted to own a 4J, but since at the time I was a student of Don Butterfield, the King 1241 was the eventual winner (no regrets, BTW).

Well, I finally got one, and I'm currently messing around with it, and I noticed that it plays quite sharp (I've heard others say this, and my research on TN has also brought up this info).

So, I decided to compare it to a 5J bugle I've got here, and I discovered that, other than the branches being wrapped differently, they are all identical except for the 5th branch (the smallest one before the dogleg) - the one on the 5J is about 2.75" longer then on the 4J. The bore is identical on the respective ends of both branches, so I've got to assume that the folks who designed and built these horns must have known about the 4J problem, and that this difference on the 5J was their answer to fix it. The "spread" is identical, so transplanting the 5J 5th branch onto a 4J therefore is a relatively simple procedure, and brings down the pitch about +/- 25 cents.

Also, I noticed that the dogleg is completely cylindrical (no taper, .687 on both ends), and is quite long (as is the large side of the MTS) so there is plenty of room to to insert a 17.5 mm (.689) 5th rotor valve anywhere in that area. Also, since the King 2340/1 is also a .687 bore, tubing and crooks are readily available to build the 5th valve circuit.

I've also noticed, as bloke pointed out in a previous thread, once the valve alignment/stem/tubing length issues are resolved, they can play quite well for their size, and play quite well in-tune with themselves. I think it would be well-suited for solo or small ensemble/quintet use.

My next step (not yet completed) is to replace the mouthpipe with one that will be a little larger (accept a King 2340/1 receiver) at the small end - I suspect (hope) this will open up the horn even more....

FWIW

[iiipopes]

Hmm. Sounds like someone at the factory all those years ago did not realize there would have to be a difference in the length of the 5th branch compared to a 2J - Have you compared the 5th branch on your 4J to a 5th branch on a 2J?

[roweenie]

I don't have access to a 2J, so I've never compared them - however, here's a diagram of the 4J 5th branch, so if you do, maybe it might help :



(The bore sizes are I.D.)