old question: why isn't there a Channel 1?

[Celt]

Answer:
There was a Channel One once upon a time--in 1945, to be precise, when the Federal Communications Commission first allocated broadcast television frequencies.

Later, however, the FCC repented its generosity and decided that TV was hogging too much of the broadcast spectrum. (Each TV channel requires a bandwidth 600 times as wide as an individual radio station does.) So the Channel One band (44 to 50 MHz) was reassigned for use by people with mobile radios.

Add that to your bag of useless trivia!

[Electronic M]

Old news to me....been in my bag of "useless trivia" for years now.

[zenith2134]

@ E-M
Thanks for that info, Celt!

[Jeffhs]

The short answer to this question, without going into a lot of history and details, is that the frequencies once known as television channel one in the U. S. were reassigned by the FCC in the late 1940s-early fifties, but not necessarily to land-mobile radio services. These frequencies, again without going into details, eventually were reassigned to the Amateur Radio Service as the six-meter amateur band. If anyone here is a radio amateur operating six meters, and has a TV that still tunes channel 1 (many late-'40s Hallicrafters sets and possibly others of that era did), it shouldn't be too difficult to retune that channel's oscillator and antenna circuits to 50-54 MHz.

BTW, six-meter operation was probably not very prevalent in areas with a channel 2 TV station, due to the risk of interfering with reception of that station. The reason is that the low end of the frequency range of channel 2 is 54 MHz -- right at the top of the hams' 6-meter band. While most amateurs did not operate anywhere near that close to the edge of the band, some did, and therein lies the problem. If an amateur were operating, for example, on 53.8 MHz, lived in an area with a channel 2 TV station, and his neighbor was trying to watch a program on that channel, the latter would not be pleased when "WB8XYZ calling WA8QRP, over" blasted through his TV speaker (along with interference to the picture), right over top of the program he was trying to watch.

I bet there was quite a bit of trouble like that in channel 2 areas in the early days of TV, immediately after the 6-meter band was opened to amateurs. I don't think there was much 6-meter activity in cities with channel 2 television stations for just that reason. This applies, of course, to television's beginnings in the late 1940s and very early fifties, when everything was on 12 channels, broadcast in monochrome and analog; NTSC color and UHF hadn't yet been thought of and the first TV systems in the U. S. were, of course, analog. The arrival of UHF in the late 1950s-'60s brought with it even more problems, not the least of which were weaker signals and a severe lack of sets that could receive the then-new UHF stations. Since most people living in areas with at least one UHF station still had VHF-only sets with UHF converters in those days, and the UHF stations themselves of that time weren't the high-power monsters they became by the '70s, the potential for interference was greater than before, not necessarily from 6-meter amateur signals but from hams' transmissions in other bands as well. Since UHF converters downconverted incoming UHF TV signals to an unused VHF channel, usually 5 or 6, a strong amateur signal appearing on either of these channels could cause real problems. Channel 5 is 76-82 MHz, six is 82-88 MHz, of course, but a very strong signal, amateur or otherwise, can blast its way past the tuner regardless of the channel's nominal frequency.

In the early 1970s, I lived in a Cleveland suburb which had an FM station on 92.3 MHz. I was living just one street over from that station's tower, and that station created very serious interference problems, not the least of which was to my TV, a 1964 Silvertone roundie, on which I could receive that station perfectly well (!) on channel 6. The problem was caused by the extreme signal strength in the area where I lived; it was just blasting its way through the set, with no regard for the tuned circuits in the tuner or anything else.

Hmmm. I wonder if DTV is prone to the same kind of interference problems we had to tolerate in the NTSC analog era.

[old_tv_nut]

Originally Posted by Jeffhs

Hmmm. I wonder if DTV is prone to the same kind of interference problems we had to tolerate in the NTSC analog era.

Yes

[cbenham]

Originally Posted by Jeffhs

The short answer to this question, without going into a lot of history and details, is that the frequencies once known as television channel one in the U. S. were reassigned by the FCC in the late 1940s-early fifties, but not necessarily to land-mobile radio services. These frequencies, again without going into details, eventually were reassigned to the Amateur Radio Service as the six-meter amateur band.

Oh, c'mon, lets get into some very interesting details about Channel One.

Channel 1 was allocated at 44-50 MHz between 1937 and 1940. Visual and aural carrier frequencies within the channel fluctuated with changes in overall TV broadcast standards prior to the establishment of permanent standards by the National Television Systems Committee.

In 1940, the FCC reassigned 44–50 MHz to the FM broadcast band. Television's channel 1 frequency range was moved to 50–56 MHz (see table below). Experimental television stations in New York, Chicago, and Los Angeles were affected.[1]

Commercial TV allocations were made by the Federal Communications Commission (FCC) under the NTSC system on July 1, 1941. Channel 1 was located at 50-56 MHz, with visual carrier at 51.25 MHz and aural carrier at 55.75 MHz. At the same time, the spectrum from 42 to 50 MHz was allocated to FM radio. Several commercial and experimental television stations operated on the 50-56 MHz Channel 1 between 1941 and 1946, including one station, WNBT in New York, which had a full commercial operating license.

In the first postwar allocation in the spring of 1946, Channel 1 was moved back to 44–50 MHz, with visual at 45.25 MHz and aural at 49.75 MHz. FM was moved to its current 88-108 MHz band. But WNBT and all other existing stations were moved to other channels, because the final Channel 1 was reserved for low power community stations covering a limited area. While a handful of construction permits were issued for this final version of Channel 1, no station ever actually broadcast on it before it was removed from use in 1948.

There's MUCH more about channel one where this came from:
http://en.wikipedia.org/wiki/Channel...American_TV%29

Read it all and you'll understand!

Cliff

[W3XWT]

Cliff, my good friend,

I found some possible errors with the Wikipedia article on channel 1... or, "Channel One" as WNBT always called it, IIRC.

If W9XZV was the first "all-electric TV station", were the others steam powered? Perhaps using disused locomotives as a joke promo I saw years ago out of the U.K.?

Also, K2XBS was really KS2XBS and KS2XBR, the latter of which was still on-air into the 1970's on channel 38 testing systems later used in Zenith's OTA and cable scrambling systems. I'm sure our friend Wayne ("the flicker kicker") can provide more info on those stations.

Ahhh Zenith... where the parts went in before the name went on!

[Electronic M]

Your recieving FM on that Silvertone in close proximity to the station sounds to me like your set picking up a harmonic. All transmitters produce some amount of harmonics (I don't fully understand harmonics, but I believe that they are multiples of the desired frequency) which the owners of the transmitters go to great lengths to suppress, but at close range to a powerful transmitter it is not all that difficult to imagine that the harmonics were strong enough to tune in clearly.

[Celt]

Yup...at times harmonics can indeed be annoying...

[Adam]

What I've always wondered about is overlap with the old FM band. It seems that in 46 and 47 they were making both radios with the old 42-50MC FM band, and TVs with CH1.

[ChrisW6ATV]

When I was a kid, I thought that there was no Channel 1 because all the TV stations would have fought to get that one. It wasn't until 1979 that I first saw a TV that had it.

I have never found out for sure if any stations ever actually transmitted on Channel 1 in the post-war period. There are lists of TV stations from about 1946 that do include several on Channel 1 around the USA.

At least one of the agile modulators I have seen (often used by us collectors to recreate NTSC signals for our collections) has the ability to operate on Channel 1. Now that I have a working TV with it (described here), I am going to set up an in-house Channel 1 signal.

[Adam]

My 721ts on ch1 using a B-T AM40-450 modulator:

[dewdude]

I had read, in some really old television installers handbook, that Channel 1 was abandoned mostly due to extremely poor performance; picked up ignition noise from cars and such.

My grandfather explained it to me this way as well. He said it was always an extremely noisy channnel, and after it was decided to not use it for TV, it was reassigned.

[Celt]

Originally Posted by dewdude

I had read, in some really old television installers handbook, that Channel 1 was abandoned mostly due to extremely poor performance; picked up ignition noise from cars and such.

My grandfather explained it to me this way as well. He said it was always an extremely noisy channnel, and after it was decided to not use it for TV, it was reassigned.

That's pretty much how I remember it as well.

[Dude111]

Originally Posted by dewdude

I had read, in some really old television installers handbook, that Channel 1 was abandoned mostly due to extremely poor performance; picked up ignition noise from cars and such.

I thought channel 1 was re-allocated for EMERGENCY use but they didnt ever use it....

http://en.wikipedia.org/wiki/Channel...th_American_TV