27-09-2016, 07:49 AM
(27-09-2016, 07:33 AM)Sparks Wrote: What on earth is spade tuning, I have never heard of it? I tried to wade through the Marconi document, but could see nothing referring to the mysterious spade tuning. (Attention span of a goldfish). I am very curious. It sounds like something I would be interested in making, if only I knew what it was!
Bob
It's in that Google Books link I posted....
Basically the tuning coils are flat wound, a metal "spade" (copper) is moved in and out relative to the coil thus altering the coils inductance, the high range coil alignment adjustments in the HRO receiver worked on the same principle except that the coil was a normal circular solenoid and the metal used was a an adjustable brass disc inside the coil.
Lawrence.
