Flashlights, vibraphones and dog whistles: TV remote controls since 1948
In the very beginning, there was no need for remote controls for radios or TV sets. But they slowly became more and more important. On the way, they could even control animals. These days, we are again approaching a point where they will no longer be needed.
Logitech has ceased production of its universal remote controls. Probably because the way we control devices has changed. The purpose of Harmony universal controllers was to clear up the heaping pile of remotes lying around our collective living rooms. But this trove no longer exists in many places. Today, a large part of the devices in our living rooms can be operated by voice control or smartphones.
When I was little, neither our TV nor our stereo had a remote control. The one at my grandparents’ place beeped when you pressed a button. While a friend had a toy car that was connected by cable to the remote control. From today’s perspective, this all seems rather strange.
Remote controls are more than just incidentals, they determine how we use associated devices. Conversely, new functions for devices also place new demands on the type of remote control. Which is why I read up on the history of remote controls.
How it all began
Even in the 1960s, the vast majority of televisions didn’t have a remote control. They simply weren’t needed. After all, only a hand full of channels could even be received. In Switzerland, there was neither private nor regional television requiring an antenna on the roof. Only Swiss television could be received, which was only broadcast in the evening anyway.
Nevertheless, the first TV remote control dates back to 1948. It was connected to the TV by cable and had exactly one button. When pressed, an image section would be enlarged. Which is why it became known as Tele-Zoom. Not exactly what the world had been waiting for.
From 1950 onwards, there were wired remote controls with better and especially more useful functions such as channel change, volume and an on/off switch. However, they remained a marginal phenomenon for the time being.
Source: Gazebo/Wikimedia, CC BY-SA 4.0
Let there be light
The first wireless TV remote control was launched in the USA in 1955. The Zenith Flash-Matic was nothing more than a pistol-shaped flashlight. The user manual even explicitly stated that you could also use a good flashlight instead of the remote control. The matching receiver on the TV was more complicated. There was a photocell in each corner of the device. Depending on which cell was selected, a different function would be triggered: turning off the device, sound, previous or next channel.
This method was decidedly elegant compared to the cable boxes. However, a TV could spontaneously switch itself on or off due to changing light incidence. This despite the fact that the light sensitivity could be customised. As once again stated in the operating instructions.
The Sound of Silence
Just one year later, Zenith launched the first remote control that worked with sound. More precisely: ultrasound. Again, the principle was very simple. The set contained one metal sound rods per key. When a button was pressed, a clapper would strike one of these rods. Each of these rods would vibrate at a different frequency; therefore, they would trigger different commands in the TV. A kind of ultrasonic vibraphone. The remote control worked completely mechanically and didn’t require a battery.
In the 1970s, ultrasonic remote controls became established. They worked electronically and required a battery, usually 9 volts. Usually frequencies around 40 kHz were used, but apparently not always: my grandmother had a TV with such a remote control, and as a small child I could definitely hear the sounds of individual buttons. Dogs and cats can also hear sounds around 40 kHz. It can be painful, but some animals find pleasure in it. In any case, such a remote control can, in a way, also command your furry friends.
Source: Phrontis/Wikimedia, CC BY-SA 3.0
There is another problem with this technique. Ultrasound is also generated in everyday life by striking metal. Which is why jingling coins or a bunch of keys could unintentionally switch a TV on or off.
Returning to the light
In the ’80s, the remote control became a sceptre of power. Whoever held it in their hand commanded its mystical energies. With the introduction of private and cable television, there were many more stations than before. Teletext, which was still in its infancy at the time, also required a powerful remote control.
During this time, infrared remote controls, which are still popular today, were gaining acceptance. They didn’t drive pets crazy and weren’t susceptible to random noise. But how? Infrared is just as common as visible light in any living room. Shouldn’t that also trigger spontaneous actions?
Well, let me explain. The lamp of an IR remote control doesn’t simply light up, but flickers at a very specific frequency – typically around 36 kHz. This doesn’t occur in a natural environment. Therefore, TVs could easily distinguish between ordinary infrared and a signal from the remote control.
Furthermore, signals were coded. Each key sends a different pulse pattern – a very fast sequence of short or long signals. The receiving device decodes short and long into zero and one before combining the individual signals into bits. Not that different from Morse code.
Coding also enabled the use of remote controls for multiple devices without them interfering with each other. The devices just had to use different protocols. A universal remote control is nothing more than a remote control that knows and/or can learn the protocols of all common devices.
The final word
If our own voice is all we require, we don’t need an additional device to constantly misplace or which sinks between sofa cushions anyway. A captivating idea. In this 1972 advertisement, the Zenith remote control is touted for those who didn’t have voice control. Because interestingly, it already existed back then – as long as you could afford a butler.
We’ve come full circle, as this slightly bizarre nerd video shows: Our friend here controls Amazon Alexa with a Zenith remote control from the 1960s. Looks stupid, but it works.
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David Lee
Senior Editor
David.Lee@digitecgalaxus.chMy interest in IT and writing landed me in tech journalism early on (2000). I want to know how we can use technology without being used. Outside of the office, I’m a keen musician who makes up for lacking talent with excessive enthusiasm.
