In April 1966, Lewis Fitch W4VRV of Columbus, Ohio built a Permeability Tuned Oscillator. It is remarkably similar to the devices we are building today.
Lewis opened his article with this:
Clearly, this guy was one of us!
His article is filled with good practical advice on VFO construction, with a special focus on PTOs. I was intrigued by the way his PTO mechanism allowed for the use of a reduction drive. This would help us avoid the indignity of attaching a digital frequency counter to such a quintessentially analog device.
Check it out:
https://worldradiohistory.com/Archive-DX/73-magazine/73-magazine-1966/73-magazine-04-april-1966.pdf
Page 30.
Thanks to Michael (VE2BVW ?) for suggesting that I dig up some old 73 Magazine articles on PTOs. A quick search revealed that there weren’t many. If anyone out there knows of good PTO articles in the ham or EE literature, please let me know.
Thanks Bill. I’ll check that article out. 73 Nick M0NTV