[drh4683]

remote UHF tuning was available on zenith and magnavox sets in the 60's. In 1969 zenith introduced the "ultra-matic tuner" It was offered with sets having space command or power tuning. The ultramatic had 6 presets for UHF channels A-F. It was entirely mechanical. You would open the door on the set and dial in the channel desired for channels A-F. Each channel had a worm gear that moved a pin up or down. The shafts were arrayed around a cast aluminum drum that would rotate via drive motor. As the drum rotated to the next UHF preset, one of the pins would make contact and move a cam on the UHF tuner. The UHF tuner was just a typical continuous tuner but it had a spring loaded return. This is how the channels could switch just by moving the preset pins up or down.
This was a very noisy system! With all the mechanical components moving produced a very loud "clunk clunk". It was much quiter operation once you got to the VHF channels. The tuner mechanisem was continuous, from channels 2-13, then the UHF tuner would active then you would go from channels A-F untill you got back to channel 2 when the VHF tuner would reactivate.
Its zeniths most intricate tuning system. For that fact, its my favorite tuner out there and works very well.

Magnavox used a motorized continuous UHF tuner. The motor would stop when the signal strength peaked, it would stop. There is a coil that fits over the 2nd IF and decected signal strength. Once the signal was strong enough, the voltage produced would click the motor relay off to stop. I had a '67 model magnavox TV with this set up and worked excellent. oldtvman has it now.
The nice feature on this set, is that the remote control actually had UHF tuning buttons so you would not need to cycle through all the channels before you get back to UHF like the zenith did.

Here is a picture of the ultramatic tuner in my '69 zenith space command 600. I got this TV about 2 years ago already. At that time, The UHF tuner needed work so it got pulled and took pictures then.