Retrotechtacular: How Old Is The Remote?

A few weeks ago we covered a (probably) bogus post about controlling a TV with the IR from a flame. That got us thinking about what the real origin of the remote control was. We knew a story about the 38 kHz frequency commonly used to modulate the IR. We’ve heard that it was from sonar crystals used in earlier sonic versions of remotes. Was that true? Or just an urban myth? We set out to find out.

Surprise! Remotes are Old!

If you are a younger reader, you might assume TVs have always had remotes. But for many of us, remotes seem like a new invention. If you grew up in the middle part of the last century it is a good bet you were your dad’s idea of a remote control: “Get up and turn the channel!” Turns out remotes have been around for a long time, though. They just weren’t common for a long time.

If you really want to stretch back, [Oliver Lodge] used a radio to move a beam of light in 1894. In 1896, [Marconi] and some others made a bell ring by remote control. [Tesla] famously showed a radio-controlled boat in 1898. But none of these were really remote controls like we think of for a television.

mysteryOf course, TV wouldn’t be around for a while, but by the 1930’s many radio manufacturers had wired remotes for radios. People didn’t like the wires, so Philco introduced the Mystery Control in 1939. This used digital pulse coding and a radio transmitter. That’s a fancy way of saying it had a dial like an old telephone. As far as we can tell, this was the first wireless remote for a piece of consumer equipment.

The Mystery Control was several years later than the wired Lazy Bones remote, and didn’t take a piece of furniture to house it (but it did take a big battery). We know you want to tear one apart, and luckily, [batteryman] has done that for us in this video.


Philco was no stranger to remote controls. Their Lazy Bones TVs predated the Mystery Control and used a flat cable under your carpet to connect the radio to the remote housed in another wooden cabinet. They weren’t alone in making wired remotes, either. Zenith introduced the Lazy Bones wired remote for TVs in 1950.


According to Zenith:

The Lazy Bones used a cable that ran from the TV set to the viewer. A motor in the TV set operated the tuner through the remote control. By pushing buttons on the remote control, viewers rotated the tuner clockwise or counterclockwise, depending on whether they wanted to change the channel to a higher or lower number. The remote control included buttons that turned the TV on and off.

Although customers liked having remote control of their television, they complained that people tripped over the unsightly cable that meandered across the living room floor.


Zenith engineer [Eugene Polley] solved the wire problem in 1955. His Flashmatic system used four light sensors at the corners of the TV. By hitting a sensor with some light you could change the channel up and down, turn the TV off, or mute the audio and, presumably, unmute it.

The only problem was the light sensors would respond to any light. So if the sun came in your window at the right time of day, it might turn your TV off. However, people loved it and Zenith had to apologize to customers for not having enough product to fill demand.

Audio Remote

In 1956, Zenith rolled out its Space Command remote. This used audio frequency instead of light. But it probably didn’t work the way you’d imagine. When you pressed a key, a hammer struck an aluminum rod producing a particular frequency the receiver picked up. This meant the remote didn’t need any batteries, which is clever. Zenith’s marketing department feared that people would think their TV was broken if the remote batteries died.

You can see the rods inside. Each rod is a slightly different length, around 2.5 inches overall, and if you guessed that means the remote has two buttons, you are right. You could change the channel down or cycle the volume from high to low and back again. Remember, back then you only had 12 channels to flip through, and probably only two or three with anything other than snow on them.

There was room in the case for two more rods and you see the cutouts for two more buttons in the case. There were models with four buttons and four rods, as well.

You have to keep in mind what the electronics looked like in 1956. The remote receiver added six tubes to the TV set and raised the price about 30%. Nevertheless, it was a success. People wanted remote control.

It is really entertaining to watch [drh4683] align the receiver for one of these remotes and hear the clicking noise of the aluminum bars being struck. There was even special test gear for aligning the remote receivers.


In the 1960s, solid state technology advanced to the point that the aluminum rods could be replaced with transistor circuits and piezoelectric transducers. This allowed for more buttons, but it did take batteries.

There are stories of people who could hear the remotes and dogs, too. It isn’t hard to imagine that random noises could produce enough energy to trigger some of the remotes too. However, Zenith claims the industry delivered more than nine million ultrasonic remotes over the 25 years they were in use.


The switch to infrared like we have today started in the 1980s with a Canadian company called Viewstar that made cable boxes. We’ve covered how those work many times so we won’t rehash that here. We never could verify that the 38 kHz was due to the frequency of ultrasonic remotes. It looks like frequencies in that range were introduced around the time of the electronic remotes. The aluminum bar remotes appear to operate about one fifth of the frequency. However, even with infrared remotes, there is some variation in carrier frequency.

For example, the NEC protocol specifies a carrier frequency of 38 kHz. Philips RC-5 and RC-6 remotes are supposed to use 36 kHz. However, because many companies used an easy-to-find 455 kHz resonator, frequencies of 37.92 kHz are common. There are other examples of other frequencies including some in the 50-60 kHz range.

One interesting note: the frequency of the IR light is also important. Many remotes use wavelengths of 930–950 nm because the atmosphere absorbs the sun’s IR emissions in that spectrum. That reduces the chances that sunlight would blind the IR receiver.


The universal remote first appeared from Magnavox (which is a Philips brand) in 1985. [Steve Wozniak] of Apple fame started a company, CL9, to sell CORE–a programmable learning remote that failed to catch on. Some say because it was too hard to program.

Even today, it is hard to find that one remote that will control absolutely everything unless you buy something very high-end. There are a few RF remotes that complicate things, and bring us back full circle to the Mystery Controller. New devices and codes appear all the time.

However, there is a growing trend to allow devices to accept control via networked devices like cellphones or tablets. So maybe IR remotes will one day be as peculiar as an ultrasonic one is today.

Next time you cradle that Harmony remote in your hand and search for the next reality show you’ll consume, take a minute to think about the history. That remote has a long line behind it tracing back to [Tesla], [Marconi], and [Lodge].

69 thoughts on “Retrotechtacular: How Old Is The Remote?

  1. I have two Philco radios with mystery controls waiting to be restored. The control receiver has almost as much circuitry as the rest of the radio and uses a telephone stepping relay to step between preset stations.
    The transmitter uses one triode tube as an oscillator that is keyed on and off by the telephone dial. There’s a second set of contacts on the dial that applies heater power to the tube any time the dial is off of its resting position. Applying 3v to a 2v tube heater ensures that it will warm up fast enough.

    Philco originally claimed that the workings of it were a mystery and sealed the case with tamper seals. When the battery, which supplied 3v and 45v was discharged, you took it to the dealer to be replaced. I think later advertising admitted that there was a battery and tube in it.

    1. Some years ago, when I was into restoring old radios, I had two Mystery Controls, but not the console radio. I did get one Mystery Control working and sold it to a guy who had the matching radio.

      If you want to see the Philco Mystery Control in action, go to Internet Archive and download the movie “The Fatal Hour”. It is a Mr Wong movie, staring Boris Karloff. The Mystery Control came out in 1939 and this movie in 1940, so it was the latest technology at the time.

  2. I had an old television from the 1950s that had a wired remote. It was probably a Zenith as mentioned above. I worked for ages to get the television working again but one of the tubes went out of it and at the time I was poor as dirt and couldn’t afford to buy them.

    1. My grandfather had the 4 button Zenith. All you hear is a click and a faint tone from transverse modes – I assume the hammer strikes the end of the rod to get the high frequency. The rods put out ultrasonics between 30kHz and 40kHz. I never heard of keys setting it off, but I suppose the right sized key struck on edge in the right way ….

    2. Keys really would control the TV.. My friend’s dad had his TV near the back door of his den. We would walk up outside the house and jangle a big set of keys and the TV would change channels. Also, certain time the bells in a telephone would turn on/off the TV. I had a great aunt who was convinced someone was breaking into her house to watch tv. Turns out, her TV would turn on / off every time the phone rang. If someone let the phone ring an odd number of times while she was not at home, the TV would be on when she got home. :-)

      1. I had an old Zenith TV from the 80s, there was a broken solder joint in the tuner circuit somewhere, throwing a tennis ball at the front of the TV would change the channel, and bouncing it off the side would turn it off. Made an entertaining remote control until I fixed it :-P

    3. I worked in a TV shop way back when (damn I’m old) To test that the remote pick up on the TV was working we would jangle a batch of keys in frount of the set. This was when the sets were getting older and the remote’s where wearing out,

    4. Once I have read a story about a parrot mimicking an acoustic TV remote. :-) The owners of the TV thought it was defective and brought it to a repair shop several. Of course with no parrot no malfunction occurred any time.

      1. My grandparents had a four-hammer Zenith Space Control, and the eventually figured out that songbirds had learned to turn it on. They appeared to be doing it deliberately because it stopped happening when they started leaving the curtains closed so you couldn’t see the TV from outside the house.

    5. I really loved to tease my dad and change the channels, turn the tv on/off or change the volume of our old Zenith System 3 tv with my keys. With a bit of practice you could figure out how to jingle the keys to do what you want (well, most of the time).

      It was a quite advanced tv for the time,, with motors to drive channel switching and volume… My dad always yelled at me when i was switching channels too fast, he was afraid i would break it. Well that thing he bought new in the late 70’th only died in the early 2000… There was a recurring problem with the power supply making it die every 5-7 years. I gave up on repairing it because the parts where becoming way too difficult fo find…

      I’ve play everything on this, my first Telstar pong game, a Colecovision, a C64, a NES and a Super NES… Lots of memories…

    6. Pretty interesting comments. I would like to see some exploration of the energy in the spectrum above hearing for all these common object when they are struck. All these rigid objects when struck to get a compression wave, as opposed to flexing, like the plate struck on edge, should resonate at high frequencies. I used to have students hold a big lab bench aluminum rod by the center and smack one end transverse to get a less than impressive low tone. Then strike it end on and the whole class would jump at the piercing pure very high pitch tone would ring out and with very impressive sustain. Mayhem ensued with the hammering of rods, and a good time was had by all. Some even figured out why you hold it by the center.

      1. I nipped this one in the bud when I pointed out that I shouldn’t be allowed to read my school work,either, if I can’t watch TV up close as it is even closer to my eyes. I got to watch up close, LOL.

  3. 38 khz i think is the pilot signal used for stere fm.

    the device would detect the 38 khz signal (emulated by playing tape at high speed through mono transmitter)’

    some noises like crowd nois on sports channels may cause stereo indicator to come on falsely.

    1. Actually the stereo FM pilot is 19kHz so it’s twice that, but yeah I agree that was probably an important factor in choosing 38kHz as carrier wave for ultrasonic and infrared remote control: components to generate and filter it were easily available.

      I remember my grandparents had a really fancy expensive Philips TV from 1975 or so with an ultrasonic remote control and a whopping TWELVE channel presets though there were only 6 channels they could receive. They used it to watch the news and that was pretty much it, and they always turned it off with the main power button because they didn’t trust that it was on standby, using power but not doing anything. It also had the mysterious words “VCR” and “VLP” on the front, by the way. I have good memories of the time that I could hear the remote control when some of the buttons were pushed; I wish my ears were still that good…

  4. Turning the channel? I should have been so lucky… operating the TV was prohibited because electrics! Only Mum and Dad were allowed to touch the controls. In hindsight perhaps they only wanted to avoid me and my sister fighting over it.

    1. Operating the TV (and using wired remotes) was prohibited because they wanted to force you to watch what they wanted. The idea for the remote came from kids who wanted to freely zap between channels; luckily, those kids’ parents worked at Philco/Zenith/whatever and stole the idea. And the wireless ultrasonic remote (a.k.a. handheld xylophone) was born.

      (No, this isn’t a true story. But it could be one of the reasons the remote was invented.)

  5. When I was a kid, my grandparents had a Zenith TV with unltrasonic remote. The receiver was a metal box that strapped on the back, with vacuum tubes inside. The TV turned on and run up the volume to max every time the vacuum cleaner was used! I took the remote apart. It “clicked” when a spring-loaded hammer struck a small bar — an ultrasonic xylophone! No batteries needed in that mechanical remote. Electrical outlets were precious and few in those days, and TV repairmen did house calls. I had a TV repairman friend (and mentor), who game me his old electronics magazines, tools and parts. He said his most common service call was usually to fix a “broken” TV by plugging its cord into the outlet. Folks unplugged it to plug in a vacuum, most commonly. To prevent anger from charging a service call to just plug in the TV, he would do a routine TV tuner cleaning (the switch contacts would oxidize over time anyway). Though usually, you could get a rotary switch working again by rotating it quickly from one extreme to the other to rub of the oxidization. Anybody restoring old equipment should know this…

        1. smartass detected @ ;-) I realized that after posting, and I would have fixed it if an edit button. But not the ‘g’ and the end, because I do not want to change somebody else’s ‘game’ to ‘gave’… :-)

  6. In Germany, IR remote controls came to be in the 70’s. I have a Grundig “portable” (45cm picture, weighs approx. 20kg) that has an infrared remote control. It even barely has any buttons on the TV itself, the front only has the power button, like they want to discourage the use of anything but the remote, like there is only a Channel Up button on the chassis and Volume +/- are swapped.
    Mechanical tuners in Germany vanished around, say, 1973 (±2 years), facilitating remote control.
    These really old IR remotes just give off a steady frequency in 50kHz increments per button. The oldest IR remote I know that used digital codes like the ones we know is a Philips from ’78 or ’79.

    1. > there is only a Channel Up button on the chassis
      You remind me of a not too old TV I had with just three buttons. Two of them were the channel up/down buttons, the other one was the menu/function/mute button. I had to press the up/down buttons while holding the other button to set the volume. Holding that button for more than 2 seconds opened the OSD menu (which was impossible to navigate with those buttons), so I had to be quick.

      Hopefully, most modern TVs don’t have buttons anymore, they have a small joystick instead. That’s much more usable than three buttons.

      1. The remote for my LG 3D TV has a tilt sensor to move the cursor. Rather difficult to use the onscreen keyboard with that though — a tendency to overshoot positions, and the cursor is NOT where you point the remote (and no calibration either).

  7. When I was a kid, I had a black and white TV that had a wired remote. It had come out of a hospital that had upgraded. The remote had a speaker with volume control on it. It had one channel button that rotated the tuner up. If I wanted to go to channel 6 from 12, I had to turn it all the way back around. It was pretty cool as I could turn the remote speaker way down so nobody knew I was watching TV when I was supposed to be going to sleep.

    1. I had a headphone for my TV, but my room was besides the bedroom of my parents and any light from my window was reflected at the balustrade of the balcony outside. Not so good.

    2. Hospital TV’s work that way to this day, the theory being that you listen from a speaker close to your ears instead of filling the whole room with sound, which would also be likely to fill the rooms on either side of you with sound.

  8. Look up IR remote receiver on digikey if Hackday doesn’t soon get around to posting my link with an explanation of why 38 kHz is only one of the many frequencies of modulation that were used to prevent interference and what else one might do with dirt cheap modules that have different center frequencies. Lots cheaper than most of the hacks presented here using wireless. Nice control over the range as well.

  9. The remotes weren’t really the problem. It was that the old stuff wasn’t easy to remote.

    It generally meant motors attached to mechanical things like volume controls and switches and variable capacitors. One could have used a stage to control volume, but that meant at least another tube, expensive and adding more space. The motors were jut another thing that might need repairing.

    That’s why remotes weren’t so common until the seventies. That’s when varactors made inroads, replacing variable capacitors. For tv sets it meant the clunky channel switches were gone, so voltage tuned things, much easier to do remotely. Since ICs made things so compact, extra transistors didn’t matter, so volume could be controlled by voltage, and the circuitry needed to decode the remote signals was easy and cheap.

    It’s now cheaper to have remotes, so TV sets and DVD players have a limited set of controls built in, and aren’t really easy to use. The remote isn’t an option. Even cheap electronics like “electronic candles” have remotes.


  10. There was one big negative with those stepper volume controls. Three volume settings then POWER OFF. Then right back on again at the lowest volume setting. Like those 3-way light bulbs the toggling of on-off cycling assured wearing out tubes and caps faster. That included the picture tube$$.

  11. I swear I remember a very basic sonic system, that used a loud sharp clicker click, like those sonic remote control cars, and the TVs too, you could bump the channel up by clapping hard enough.

  12. Why do none of these articles on the history of the TV remote ever mention the Magnavox Phantom?
    It was NOT the hammer struck aluminum rod type. The buttons pushed quite a ways and looking in the front I could see what appeared to be two white, plastic whistles behind a wire mesh. When the buttons were pushed it made a very quiet *chuff* sound.

    They sort of resemble a chunky, brown, original series Star Trek Phaser 1.

    The Philco Mystery Control totally looks like a DHD from Stargate.

  13. As a little kid(early 70s) seeing my first ‘TV clicker’ I assumed there would be a battery and transmitter. It broke my brain a bit when better-off-uncle showed me the clicker, and even opened it up for me; not a damn bit of electronics to be seen. To this day it has troubled me a little, but apparently not recently enough to know what to search for on the internet. By the early 80s when the first piezo clicker grill starters came out but the clickers were gone I convinced myself it was some sort of piezoelectrical tuned circuit or spark gap TX with the clicking and and all, or later that I had just somehow not remembered seeing electronics which obviously had to have been there and let it go. Thanks HAD!

  14. my folks had a big console Tv that used a 4 button metal bar remote. I remember playing with my keys as a child (house, bike and locker) and being able to change the channel much to the irritation of my father.

  15. “When you pressed a key, a hammer struck an aluminum rod producing a particular frequency the receiver picked up.”

    Oooohhh! THAT EXPLAINS all the clicky-clacky remotes I saw (in American sit-coms and such) — it was mechanical to avoid batteries. Neat, I learned something.

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