- #1
homerwho
- 42
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- TL;DR Summary
- I had an old dial tune TV set. Obsolete now.
It had a small button that I think was suppose to improve reception. What did that button do physically?
Button or dial? It was common to have a "fine tune" dial control on those early sets, since they did not have frequency synthesizers and other ways of making very accurate frequency adjustments.homerwho said:Summary: I had an old dial tune TV set. Obsolete now.
It had a small button that I think was suppose to improve reception. What did that button do physically?
Dial. It had a button that when pressed it would latch. It did have the fine tune knobsberkeman said:Button or dial? It was common to have a "fine tune" dial control on those early sets, since they did not have frequency synthesizers and other ways of making very accurate frequency adjustments.
"Well, which is it young feller?" (Quiz Question -- what movie is that from?)homerwho said:Dial. It had a button that when pressed it would latch. It did have the fine tune knobs
homerwho said:I don’t recognize the quote. But it is humorous.
My guess would be either a fine tune on the frequency, or a change in the AGC range.homerwho said:Well old timer what do you think the change was. It never did didly swat. I’m interested in what it was.
I assume that's a typo, yes? Or is there some part of the country where "diddly squat" is "didly swat" ?homerwho said:It never did didly swat.
It is whatever electromagnetic noise there is at the frequency of the channel. That noise will vary from channel to channel and from one location to another.homerwho said:I have another question. If I tuned that to channel 11 but l don’t have signal. What is displayed. I realize it’s static. But is the static the same channel to all without a broadcast?
So you were receiving VHF signals, channels 2 -13.homerwho said:I have another question. If I tuned that to channel 11 but l don’t have signal. What is displayed. I realize it’s static. But is the static the same channel to all without a broadcast?
Actually, our first color TV back in the 70's had one. It was a momentary contact button, and when you pushed it, the picture would jump and wriggle, as if it was a reflection in a pond you had dropped a pebble into. It would settle down in a couple of seconds, with possibly some change in the color. IIRC, it was supposed to counteract accumulated magnetization of the chassis and picture tube.256bits said:I never knew a television that did have a de-gausser button on the unit, and I have known a few.
As did my first trinitron computer monitor. Not sure its the switch in questionsandy stone said:Actually, our first color TV back in the 70's had one. It was a momentary contact button, and when you pushed it, the picture would jump and wriggle, as if it was a reflection in a pond you had dropped a pebble into. It would settle down in a couple of seconds, with possibly some change in the color. IIRC, it was supposed to counteract accumulated magnetization of the chassis and picture tube.
A picture would help.homerwho said:But it had a three position push button.
A quick Google Images search on Panasonic TV 1980s turns up some possibilities. Here is the CT9010, which does indeed have an AFT button...homerwho said:It was a Panasonic from the 80's.
That's my bad. The link was kind of hidden at the end of my post after the picture.homerwho said:I didn't see the Wiki link.
That is my impression, although I've never designed that particular kind of circuit (I've designed PLLs, which are a related type of circuit though).homerwho said:Is it a tracking function of some kind?
Wikipedia said:In radio equipment, Automatic Frequency Control (AFC), also called Automatic Fine Tuning (AFT), is a method or circuit to automatically keep a resonant circuit tuned to the frequency of an incoming radio signal. It is primarily used in radio receivers to keep the receiver tuned to the frequency of the desired station.
And maybe this is why it didn't seem to do much. If you try to use it to improve the picture right away, that's not what it was for. It was to keep the picture tuned well as you watched the same channel for a while (especially right after you turned the TV on and the tuner circuit wasn't warmed up yet).homerwho said:It never did didly swat
berkeman said:That is my impression, although I've never designed that particular kind of circuit (I've designed PLLs, which are a related type of circuit though).
My impression from the Wikipedia article is that the feature is used to help stabilize the tuner's lock-in to a channel once is is tuned well. It helps to prevent drift of those old tuner circuits with temperature and time as you stay tuned to the same channel. So I'm guessing (somebody find the old manual please?) that you would change the channel knob to the channel you wanted, turn the Fine Tuning knob to get centered on the broadcast signal, and then turn on the AFT/AFC.
As long as the TV was still turned on, that would help to keep the TV tuned right on the frequency of that chosen channel. If you wanted to change channels or if you turned the TV off and later turned it back on, you would need to do the fine-tune knob (with AFC off) again first, and then re-engage AFC. But that's just my educated guess, unless somebody can remember better or find an old TV manual...
My guess, is the button.. bypass or applies the fine tune-if it be auto or knob adjusted...homerwho said:Summary: I had an old dial tune TV set. Obsolete now.
It had a small button that I think was suppose to improve reception. What did that button do physically?
Welcome to the PF.ParagustIS said:My guess, is the button.. bypass or applies the fine tune-if it be auto or knob adjusted...
Sorry i just replied to the first question. I scrolled through the posts. Didnt see anything lf bypass /engage button.. sorry if i missed it. I registered just now as i recognise a gold source. I am still to fill oit my profile.. apologies, i don't get offended.. if I am ever in the wrong. Just tell me... i like to be wrong, it the only possible condition to deliver true learning. No game of ego confirming for me. Shoot me Down at every sight... there's nothing greater. Nice to meet yall, sorry. I know this isn't the right place.. ill go intro in rhe correct section.berkeman said:Welcome to the PF.
Did you read any of the posts in the rest of this thread? Or just the first one...
The small button on tube television receivers is used to change the channels on the television. It is also known as the channel selector button.
The small button on tube television receivers is important because it allows users to switch between different channels and access different programs on the television. It is a crucial component of the television's functionality.
No, the small button on tube television receivers is specifically designed for changing channels and cannot be used for any other purposes.
The small button on tube television receivers is connected to a circuit that controls the tuner of the television. When pressed, it sends a signal to the tuner to change the frequency and display a different channel on the screen.
No, modern televisions use remote controls or touch screens to change channels, so the small button on tube television receivers is no longer necessary. It is only found on older tube television models.