Hmmm… I thought it was a big capacitor charging up.
I hear it for sure. I’ve got a CRT in the basement and if I leave it on (with nothing on the screen, say after video games) I can definitely hear it. I’m 35 and have bad hearing but I definitely hear in that register! I have tinnitus too.
Flyback transformers only make the whine when the stack of metal plates that make up the core are starting to delaminate. As long as they’re tightly wound and varnished together, no whine. With age, as the plates slowly come apart and can resonate, and with cheap transformers never properly sealed or wound, whine.
I can hear it, I’m 43 and I also have tinnitus in my left ear.
I’m 32, and I can hear it well enough that I can’t watch that particular TV at a very low volume (say, below 9 or so) because the whine overwhelms the audio.
Missed this. I checked this online frequency test, and I can just barely hear the 16khz signal. So I guess I can still hear it. It’s just that the ringing in my ears is louder.
Note that, on my system at least, the 21 and 22khz ones don’t work right. Also note you can test to see if they are working by playing another one before the first one stops. They will briefly overlap, and you’ll hear an interference tone.
Just to complete the answer, TV was originally even numbers (30 frames per second, etc.) The addition of color required additional sync features to the signal and changed the timing very slightly, so anyone who works with broadcast video is familiar with the odd not-quite values like 29.97 fps.
Standard color, by the way, is very low-res. If you suppressed the black and white portion of the signal (“luminance”), what you would see is fuzzy colored blobs barely corresponding to identifiable objects. It was a lot more like “colorizing” than you might think.
Modern pixel-driven video is different, of course. Every pixel on HD is a specific color and intensity, none of the visual blending tricks used with CRT/old broadcast standards.
Ooh, neat link. My hearing seems to drop out around 19K.
It’s nice, but it would be better if they were longer and would fade in so there wouldn’t be any telltale clicking.
My father in law still uses a CRT TV and I can hear the whine if it is turned in before the cable box. I could also perceive it in classrooms with the built-in TVs that would get that one education channel if someone left it on. I asked a teacher if I could turn it off and everyone looked at me as if I had two heads.
I used to be able to… back when I had a CRT monitor, which would have had to have been no later than 2008 or so (I was 36 at the time)
No idea if I still can (42 now). I can clearly hear the 15k tone on the test, but not the 16k.
I hear it when the TV is off. When I unplug it the sound stops so it isn’t my imagination.
This. Until today I thought I was the only one who heard it.
I heard it all the time as well. Walking into an electronics store that sold CRTs was very annoying. I remember, as a teenager, Sears had all their TVs by the mall entrance. I could tell when we walked by Sears with my eyes closed (not that I did, there were too many fine girls to look at).
I have no idea if I could even hear it now. I can’t remember the last time I saw a CRT.
I took the test in BigT’s link and I heard the 16k tone but not the 17k tone, so I could probably still hear the TV’s if I encountered one. Just turned 40, in case you were interested.
When we were young, our range of hearing was well beyond the flyback frequency. As we age, our hearing usually decreases, and the ability to hear high frequencies is gradually lost. By 45, most people can no longer hear the flyback frequency; it’s still there!
I’ve always been able to hear it (in my 30s). This reminds me of one time in primary school when the teacher had the screen on, but the connected VCR turned off. So the TV wasn’t displaying anything or making any sounds (that she could hear). And she just stood their obliviously giving her lesson while it’s going eeeeeeeeeeeeeeeeeeee right next to her.
This was a major drawback to these things. That, and the flicker.
I tried the online frequency test. I can definitely hear them all, although above 17 khz I was forced to turn my audio volume to maximum and turn off some background fans to hear them clearly. The 22 khz one is right on the edge of perceptibility, but I am hearing the tone. This is using $120 sennheiser headphones and a Xonar audio board.
I have heard (and still hear) the whine when I’m near CRTs, too. It’s one of the many reasons I’m thankful this is the age of LCDs and LED displays and such–much fewer CRTs around to hear that whine from.
The barber shop I go to still has an old Magnavox CRT TV that I hear the whine from.
I remember in high school, one of the computers in one of the computer labs had this really huge, old CRT monitor that would make a very loud “BONG! EEEEEEEEEEEEEEEE!” sound upon the computer being booted. I hated that particular machine, and the other kids would avoid it, too, unless it was the last machine in the room available.
The household TV here emits a high-pitched whine when it’s turned off.
I have tinnitus and that’s the way I describe what I hear 24/7.
Not many people have CRT televisions anymore so I get blank looks from the youngsters.
The flyback transformer is part of a pretty nifty refinement in television set design. I hope I get all this right, as it’s been a long time since I heard or thought about it, but if anybody sees anything wrong please tell us about it.
You need a voltage that goes up steadily and then suddenly drops back to its initial value, over and over again, very rapidly – you need it to drive the horizontal deflection coils in the yoke to steer the electron beam across the screen (the steady upward voltage) and then suddenly “retrace” or "fly back"to get back to the starting edge of the screen (the sudden drop). So there’s a circuit generating that, and it’s powerful enough to drive half the big coils in the yoke.
Since you have that waveform available, and it has a steep voltage drop that would create big voltage spikes in a transformer, you can use it to drive the primary coil of the high voltage transformer that creates the electron beam power supply, which is thousands of volts, perhaps ten thousand or so for color television. So you use this voltage with its flyback waveform to power that transformer, hence its name. With that kind of power driving it, the transformer itself (a relatively pricey part of the television) gets to be smaller and cheaper. The transformer doesn’t cause the beam to fly back, it’s just hitchhiking on the flyback system to take advantage of the rapid changes in its output.
So, what else could benefit from that waveform? The power supply for the audio amplifier. If you drive the power supply from 60 Hz (or 120 Hz), those are fairly audible frequencies and you need a big capacitor (or even fancier things) to filter them out. Better to use this high frequency power and save money on the filtering.
Thus the horizontal beam steering circuit also provides power to the high voltage transformer and the audio amplifier, for two different reasons.
It’s amazing how design tricks like this saved money on all those television sets.