Interesting whistle was the Heterodyne, went by on auction. Went for big dollars to an obscure collector in Kentucky. Probably just hoarded and put away into some box in a closet !!! A tube shaped whistle with what looked like 6 little slider whistles together just before the mouthpiece. All one unit. Will have to look for another !!!
Too bad that more couldn't be learned about it, but too costly for us on auction and now too obscure in its final resting place. Twice dead now. First after production, as little further is known about it at its peak and then again upon resurfacing — it is now entombed again.
Oh, if only whistle collecting would grow out of infancy and into childhood —at least. Then we could all benefit !!!
For now we publish what we can and watch the rest go by….