I've always wondered about what frequencies US remotes used. The remote from my 1960 zenith SC 300 will also operate my 68 Curtis Mathes in every way.

Was there a common manufacturer for these remotes, did they have similar parts, or was there just a general frequency these sets used?

Anybody have experience with US remotes, how they worked, and the frequencies they used?

Just curious....

A zenith system 3 remote worked an older zenith chromacolor cole set I have. Same freqs, different button functions betwen the two. I have removed all extra buttons from remote that dont work TV- easier for me to remember which buttons for what functions. The LAST US remotes have the most buttons, so logically would have the most freqs to use for an older TV. This is great since older remotes in good shape are hard to find. The ZOOM feature evens works with altered remote.

:thmbsp: :yes:

I think this may have been the main reason ultrasonic remotes were phased out. There's no way to stop one remote from controlling the wrong device. Pretty much any randomly selected remote will operate at least some functions on any remote TV.

Zenith probably licensed the ultrasonic technology to others, so they probably used the same frequencies. My 1958 Space Command will operate my 1977 model.

Funny you qualified the remotes as "U.S.", I'd be surprised if there were any remote sets built in the ultrasonic era outside of the US/Canada. We have the longest walk from the couch-to-TV. When I was in Germany, ('03) a "big" fridge was 7 cuft! I loved Germany, but to live there, I would require three items to be imported...

1) My Fridge
2) At least one big car, if only to drive up/down the driveway
3) a US toilet. (Don't ask)

Here in Europe tv sets from early 70 to mid 80 used ultrasonic remote controls. All of these were entirely transistorized units and usually worked with a 9v battery. Functions were usually channel change (they didn't actually change channels but let the user choose directly between usually 7,8,12 or 16 memories where one could store favorite channels),volume,brightness,color intensity,sound mute, reset,on/off. Other less usual functions could be the recall of clock on screen or tone adjustment.
Remote tuning on ultrasonic remotes came on late models just before this technology went out to leave space for infra red remotes. Here are few tipe of european ultrasonic remote controls. (pict.1 left: Telefunken supersonic 200. right: Loewe Sensotronic. pict.2 left:Dumont. center:Nordmende.right:B&O Beovision control module.)

I can remember making old Zenith "Space Command" R/C TV's change channels etc. by shaking a ring of keys in front of the receiver :-)

I once took an ultrasonic receiver and built a frequency copnverter to bring the ultrasonics down to audible frequencies. It was interesting to hear what items were loudest. Dropped silverware could be pretty good, as well as keys.

Some time later I had a Heathkit with ultrasonic. We came home to find the dog watching TV. At first I thought his chain collar jingling had done it, but couldn't duplicate it. Much later, we found he was hitting the big 2"-square on-off buttons accicentally with his tail!