OK, here is yet another picture of my Mighty Midget's Mate receiver, this time with yet another main tuning dial. I gave up on the large reduction drive on the right -- it worked fine but was very stiff. I cracked open a smaller version of this very common Japanese-made reduction drive, but in this smaller one I was kind of surprised to find a Jackson Brothers drive in there. I now had three of these beauties available -- all of them worked fine but with considerable difference in ease of turning. I picked the one that was easiest to turn.
I had to cut the main shaft of the beautiful Hammarlund 35 pf variable cap that I am using. This was dangerous, because of the risk of messing up the delicate bearings. I stayed out of trouble by putting the tip of the shaft in a vise and then cutting the shaft with a small coping saw. This prevented any force from being transferred to the bearings. It worked.
I was careful to try to line up the shaft and the reduction drive as closely as I could.
I needed something to serve as the tuning indicator. I used one of those small CDs that often carry the drivers for cheap electronic devices. It fit nicely. A standard sized CD was too big.
The final element was the knob itself. I had an old Drake 2-B knob in my junk box (who sent me that?). It was perfect and added a nice touch of soul to this old-new machine.
I built this receiver in 1998 and when I finished it I thought it was pretty good. But it is much better now. It has a nice 455 kc Toyo Crystal-Mechanical filter. The tuning ranges on 40 and 75 now line up perfectly with the phone bands. It now has a fuse in the power supply. And the tuning is now SMOOTH.