Those of you who grew up with old TVs may remember doing all kinds of strange things to improve the signal, such as wrapping the antenna with foil, using foil pans, having to physically hold the antenna with your hand, and so on. While I can understand that the days of early TV meant weak signals and poor receiver circuitry, what I don’t understand is why owners had to make those kinds simple modifications to the antenna. Putting foil on the antenna isn’t crazy 21st century tech, so why didn’t antennas just come that way if it helped? It seems like making a good set of rabbit ears would have been the best simplest way for manufactures to ensure their TVs had the best possible signal.
One possibility is that none of those things made a difference, but I can remember having to actually keep my hand touching the antenna for a good signal to come in. If I let go, then the signal would get worse.
I assume you are talking about the US. I think most parts of the US were served by multiple TV transmitter locations? That meant TV signals were coming in from different directions. Those modifications likely made the antenna more sensitive to signals from one direction, but less sensitive in other directions.
Not my area of knowledge, but I think that putting aluminum foil on the antennas, or having a person hold it/them, increased the surface area and gave them a better ability to ‘catch’ the signal.
“Rabbit ears” are cheap, and work OK in strong-signal areas. If you were outside of those areas, you weren’t going to get good reception with the built-in antennas, and needed to add something like this to your roof (with a rotator, if you wanted best perfornace).
If you were in a fringe area, adding aluminum foil or holding the antenna might increase the gain just enough to get a decent signal.
Basically an antenna is something that receives radio waves. You are an antenna because you can block the waves. When you touch the antenna you are simply making the antenna bigger. The same could be accomplished by making the original antenna bigger, but $$$. If the ones they made worked for most people that was the sweet point. Bigger antennas might do better for a small number of people, but would cost more for each one.
The foil accomplished the same thing.
Sometimes standing close without touching also improves the reception. I believe in those cases you are simply blocking interfering signals.
My grandparents lived out in the sticks and always had a yagi TV antenna on a rotor. I quickly learned which directions Shreveport, Oklahoma City, and Dallas were.
It’s not that you want to add area to the antenna, necessarily. You want it to resonate with waves arriving from some angle which you usually don’t know very well. Because you can move aluminum foil and wires and whatnot around very rapidly while you get feedback in the form of picture quality, you can really do quite a great deal of optimization, especially if you’re frustrated and don’t have anything else better to do while wishing you could see your program.
Now, the construction quality was miserable. It was perfectly possible to make a better antenna right from the factory, like the yagi beam UncleRojelio’s grandparents had. There’s a pretty good chance that thing was gorgeous and worked great.
The point remains that there was certainly some material other than tinfoil that would have worked better, and in some shape other than the half-bent plate with the holes in it we jammed on there. And if the plate we jammed on there cost 17 cents then I’m sure a better job could have been done in mass manufacture for a dollar.
I’ve often wondered the same thing, and never gotten a satisfactory answer. Making a better set-top antenna should only have required a bit of knowledge, calculation, and wiring. There’s no reason it needed to be so difficult.
It may be that the answer lies in the size of the waves themselves. This is only speculation. But sometimes with EMP a small thing like a 16" set-top gizmo and large thing like a 5’ roof top dealie may be the actual size ratio that gets you from one level of quality to the next. There may not actually be any improvement to be gained in between. Adding a 5’ human, of course, does help.
I do recall a revolution in discovering that the house’s electrical wiring could be used as an antenna. Of course this corresponded with my Mother’s discovery that vacuuming could only be done during the afternoon kid’s TV hour, which caused all kinds of snowy distortions.
It is an interesting general rule about engineering, that the skills of making something for a profit, and the skill of understanding how it works, are often separate, disparate, and found in different people.
The people who understand how to make a better antenna are not the same as the people who understand how to make an antenna.
Having done a lot of research in the past few years on antenna designs, let me say this: Antennas are not easy!
The cheapest and best antenna is also the largest - a half-wave dipole. At VHF frequencies, it would be around 9’ long, which is clearly not going to be practical inside a house.
Also, VHF TV channels span a 4:1 range, meaning that a single, fixed-sized antenna isn’t going to work well over the entire range.
Also, getting the biggest signal isn’t always what you want for TV reception - in cities, the signal can take many paths as it bounces off of buildings, resulting in “ghosting.” So, you might want to trade some gain for directionality. But, that means that you might not be able to receive a weaker signal at all.
The TV manufacturers were mostly interested in solving the “80%” case - if they could make millions of city and suburban satisfied, they didn’t really care that tens of thousands of people in fringe areas needed to use an external antenna. And, those people generally didn’t mind, either.
Note that none of this has changed. I can get maybe 6 OTA stations with an antenna in my house, but over 50 with a directional antenna pointed at South Mountain - the main broadcast antenna location for Phoenix.
I remember those. Well into the eighties, those things sprouted from every rooftop in New York City.
NYC was (surprisingly, if you’re not from here, not that much of a surprise if you are) just about the last place in the United States to get cable. We were stuck with broadcast TV and nothing else well after most of the country got cable. The reason being that our august leaders were waiting to see which cable company would pony up the biggest bribes for the franchise.
For that matter, early TVs needed a lot of low-tech modifications, as well.
Your basic 1950s black and white TV had three controls you never even hear about anymore. “Fine tuning” was used to slightly alter the wavelength of the channel you tuned into, as early TV transmitters occasionally drifted off their frequencies. Horizontal and vertical hold were manual controls you played around with when the picture started to roll or go crooked.
There’s a legend that Earl “Madman” Muntz literally took a competitor’s TV and started pulling out components. If the picture or sound went out, he reinstalled the component. If the set continued to work, he left it out. Muntz eventually came up with a line of very cheap TVs that only worked with the very strongest signals. They sold well in large cities, but were worthless if you lived more than about 10 miles from the transmitter.
There was a time when you frequently had to adjust the set controls, and some of the early circuits in the sets weren’t very good either. We had a 4-ft dipole on the gutter soffit to receive the 405-line VHF signals, later the city decided it didn’t want TV antennae on its properties and fitted an early cable system from Rediffusion. I remember there was some controversy because they tried to charge rental for it even to people who didn’t want television. Eventually that system was obsolete and people had to fit new antennae on their chimney stack to get the then-new 625-line UHF signal, and eventually colour television when that started here in 1969.
I disagree with the “early” designation in the OP. Then and now lesser antennas can be effected by simple changes involving human touch or small bits of metal.
Rabbit ears made a comeback in the early days of digital TV. But those flat indoor antennas with “amazing 30 mile reception” are common. (Of course they aren’t nearly as good as the claims.) Since you don’t have easy access to the bare wire in those it’s not as easy to experiment with them like you used to. Also, being digital the issues of snow/ghosts/etc. are replaced by a whole different set of issues.
And TVs now don’t come with antennas.
If you hook up rabbit ears to a modern TV and experiment with them, you’ll see dramatic changes as you adjust/touch/add metal to them.
Also, old school tuners in TV and radios were often much better than what you found later on. I once bought a garage sale TV that had some tubes in it. I was amazed that the built-in rabbit ears got a signal from 100 miles away. And no one listens to clear channel (lower case) radio stations from a 1000 miles away anymore so you’re lucky if your radio gets most of the local stations clearly.
this is nonsense. like beowulff says, when it comes to TV reception the best you can hope for is “good enough.” if you’re in the “strong” region (close to the transmitting tower) then the antenna almost doesn’t matter; I’ve had even modern TVs pick up HD broadcasts with nothing more than a straightened paper clip jammed in the RF jack.
it’s when you’re in the “distant” or “fringe” regions where the antenna design really matters. and again, as has been said, the “best” antenna in that case would be huge. So the problem is not that “people didn’t understand how to make an antenna,” it’s that the only practical antenna that could fit on the TV had to be a compromise, and it relied on the end user (who probably knew nothing about antenna directionality/pattern, gain, and resonance) to figure out how to orient it properly.
One antenna I remembered working reasonably well was one that had a dial on it. It was a flat base with both a set of rabbit ears and a round antenna. The dial had like 10 positions and the signal would change depending on the setting. I’m not sure what was on the inside, but it must have been something which allowed it modify the reception similar to us doing all those manual tricks with foil and coat hangers.
And like was said above, even now the antennas leave a lot to be desired. I watch TV from OTA signals and sometimes have to tweak the antenna a bit to get rid of the artifacts. But in general the signal is much, much better than what I remember from back in the 70’s and 80’s even when the antenna isn’t in the perfect position.
And unless you’re in one of the few places that still has a station that actually broadcasts on the VHF band (WBBM in Chicago and WJZ in Baltimore are probably the largest ones left) the rabbit ears don’t help at all. The round antenna is the one that picks up UHF signals.
To answer the OP, it’s because rabbit ears were just barely an adequate antenna for VHF signals. They could bring in a signal within 20 miles of the transmitter, but in many of those situations they also picked up echoes that arrived a few milliseconds later, producing “ghosting.” Bits of foil, or a sweaty hand, increased and in some cases tuned the element of the rabbit ears.
At suburban or exurban distances you needed a roof-mounted antenna with elements of different lengths related to the wavelengths of the 12 VHF channels, and it needed to be pointed pretty directly at the transmitter. Tricky business in cases like UncleRojelio’s kinfolk (Antlers? Atoka?) receiving from several distant cities. The extension or retraction of rabbit ears was presumably to “tune” them to wavelength multiples, but few people understood and used them that way.
Experiences with today’s HD televisions are not all that relevant, as they are receiving a digital rather than analog signal. It either gets there or it doesn’t.
You work in manufacturing? You have a degree in communications?