Great share. Important data transmissions.
Whatever happened to Channel 1?
21–30 of 58 posts
Re: Whatever happened to Channel 1?
#22tl;dr as more spectrum was used in the late 1940s a channel had to be freed up to deal with interference issues so they picked channel 1 and simply choose not to renumber. You'd think the article would explore why they didn't renumber, but nope. Legacy hardware and possible consumer confusion seem like the most likely speculation.
you tl;dr people are doing the lord's work. thank you
So instead of reading. --> fast paced audio.
Re: Whatever happened to Channel 1?
#23Project idea: Make a television system from vacuum tubes that broadcasts in the unlicensed home bands (2.4GHz & 5GHz). It could be either digital or analog, but it needs to use vacuum tubes. I'd like to see if such technologies would have been possible back in the 40's. Bonus points if they could transmit hi-def signals (1+ megapixels)
You "might" be able to do transmissions that high with https://en.wikipedia.org/wiki/Krytron
No post body was provided.
Re: Whatever happened to Channel 1?
#24Australia even had channel 0: https://en.wikipedia.org/wiki/ATV_(Australia)
Re: Whatever happened to Channel 1?
#25I always wondered why cable networks couldn't have a Channel 1, even though it wasn't allowed on broadcast. After all, there's no other radio traffic in a coax cable to compete with.
I suppose it could have posed a problem if there was any RF leakage from the cable network.
Re: Whatever happened to Channel 1?
#26I always wondered why cable networks couldn't have a Channel 1, even though it wasn't allowed on broadcast. After all, there's no other radio traffic in a coax cable to compete with. I suppose it could have posed a problem if there was any RF leakage from the cable network.
Probably because by time cable came out, TVs were not manufactured that could tune to channel 1.
Re: Whatever happened to Channel 1?
#27Not all the channels were usable in one area. Tuners were not very good at rejecting harmonics back then. Today, we have phones with four or five radio receivers and three transmitters operating without interference. It's amazing that works. Receivers are far, far better than they were in the tube era.
Doesn't a more sensitive receiver make the harmonic issue worse? In one case it fades out into background in the other you precisely measure it!
It's not that modern receivers are more sensitive, but that they are more selective. Harmonic or "image" rejection can achieve 20 to 60 dB in commercial applications today. The first and last sections of this paper may help explain: http://www.plextekrfi.com/images/pdfs/RF_mixer_design.pdf
Re: Whatever happened to Channel 1?
#28channel 1 in the United Kingdom
For the sort of "channels" discussed in the article, the UK hasn't used a channel 1[1] for TV since 1985, as VHF was only used for the older 405 line TV system. Newer 625 line analogue TV[2] was and digital terrestrial TV is UHF only in the UK, and UHF channels are numbered from 21.
For convenience most TVs mapped the channels onto buttons 1/2/3/4 for analogue but behind the scenes they would be something like channels 27/29/31/33. Modern DTT channel numbers are also completely separate from what radio channel each TV channel is actually being carried on.
[1] The definition of "channel 1" is different in different countries. https://en.wikipedia.org/wiki/Television_channel_frequencies
[2] BBC2 was UHF / 625 only at launch in 1964, BBC1 and ITV started in 1969 when they introduced colour. Analogue ended late 2012.
Re: Whatever happened to Channel 1?
#29Although I can't find it in his online bio former FCC commissioner James Quello was an early television pioneer at Michigan State University in the early thirties.
The campus ham station, W8SH, has pictures in their archives of Quello's setup which could only transmit pictures the length of the engineering lab.
Re: Whatever happened to Channel 1?
#30I always wondered why cable networks couldn't have a Channel 1, even though it wasn't allowed on broadcast. After all, there's no other radio traffic in a coax cable to compete with. I suppose it could have posed a problem if there was any RF leakage from the cable network.
Probably because by time cable came out, TVs were not manufactured that could tune to channel 1.
You didn't select cable channels with the tuner, though. My recollection is that you attached the cable box to the TV, tuned the TV to whatever channel was used to display hardline input, then selected channels on the cable box.
Eventually cable-ready TVs came out with the cable selector built-in, but they still weren't using the radio tuning mechanism to select hardline cable channels.