Beginning of June I received a supply of thin wall aluminium tubing in various sizes, and I changed the design for all low whistles to use this thinner tubing (ca. 1.2mm wall thickness). The results are lighter low whistles with increased responsiveness and more efficient fipple wind ways for easier blowing and increased dynamics. The length to bore ratios are also optimised by using a wider range of tubing sizes.
Before that I used the same 16swg 7/8" tubing for low F and G (as used in Overton whistles), now I use different tubing for these keys. It blew my initial grouping of whistles into four different “classes”, each with its own tube size. But the results are well worth the differentiation!
Here is a pic of a G and low F whistle:
I kept the “box-ear” design for added power.
The whistles are tunable and I use “TechCork” inside a groove on the body, to give a good slide. TechCork is a composite of cork and synthetic rubber and is tougher than a plain cork sheet, and has a high resistance to be permanently compressed, outperforming cork in that respect. It should last well, and I see no need to disassemble the whistle for storage, as is recommended for corked tenon instruments.
I was also experimenting with adding a Sterling silver plate to the upper fipple tip, to help anyone who has issues with touching aluminium with their lips. See this topic.
The low D design has not changed, as I was using the thinner tubing already for a while. I had very good feedback from the people who bought a Bracker low D, and all the people I demonstrated the whistle. I am thinking of starting a low D whistle tour, but this will be another topic.