davisdynasty83 <davisdynasty83@yahoo.com> asked [TD V24#116]:
> I've always wondered what happened to Channel 1 as a viable
> television channel. Is there a substantial reason behind this?
> I am very interested in this particular issue and if anyone
> could provide me with any information pertaining to this
> subject I would greatly apprecaite it.
An excellent narrative on this subject is "Whatever Happened To
Channel 1" by David A. Ferre (Radio-Electronics, March 1982,
43-46,89). http://www.tvhistory.tv/1946%20RCA%20630TS%20TV.htm
PAT added the following comment:
> Now cable-ready television sets and channel one is a totally
> different matter.
Indeed. Except for channels 2-13, cable TV channel-number assignments
differ in frequency from same-number broadcast channel assignments. A CATV
Frequency Assignment chart is posted at
http://www.annsgarden.com/telecom/CATV.html. My previous post about Cable
Channel 1 is at http://tinyurl.com/5uljg.
Michael Quinn <quinnm@bah.com> wrote [TD V24 #117]:
> Along this line, and at the risk of perhaps being slightly OT,
> if anyone knows why television uses channels while radio uses
> frequencies (for the most part, that is, the 88 channel) FM
> Marine Band in the 156 MHz range being an exception), I would
> be interested in hearing about it.
Historical accident, cultural inertia, administrative convenience, and
commercial branding.
Back in the early days of radio (before Congress enacted the Radio Act
of 1927), broadcasting was a free-for-all. Domestic frequency
assignments were made by the Department of Commerce on a more or less
first-come-first-served basis. Many foreign governments didn't even
have a mechanism for assigning frequencies; some stations, operating
without (or ignoring) governmental authority, simply picked their own
frequencies. Even the boundaries of specific "bands" (as we use the
term today) weren't uniformly defined. Given the chaotic nature of
things, it's not surprising that the Commerce Department didn't assign
channel numbers.
The legacy of this chaos lives on to this day: we still use frequency
designations in the domestic AM broadcast band and the international
shortwave bands.
In order to impose some sort of order on the situation, Congress
enacted the Radio Act of 1927, creating the Federal Radio Commission.
A few years later, it enacted the Communications Act of 1934, which
created the Federal Communications Commission to replace the FRC.
Both commissions were charged with responsibility for managing the
radio spectrum.
Over the years, the FCC's frequency-assignment policies have evolved
into three patterns:
====== ASSIGNMENT by BAND ======
In some bands, the FCC simply assigns the entire band to a specific
service, and leaves it up to licensees to assign specific frequencies
within the band. Examples of this policy include the amateur radio bands,
the common-carrier satellite C- and Ku-bands, and the DBS bands.
====== ASSIGNMENT by FREQUENCY AS CHANNEL NUMBER ======
In some bands, the FCC assigns "channel" numbers to specific frequency
blocks, but uses the center frequency of the block as the channel
number. Examples:
Radio Control (R/C) Radio Service (47 CFR 95.207):
http://kauko.hallikainen.org/FCC/FccRules/2005/95/207/
Paging operation (47 CFR 22.531):
http://kauko.hallikainen.org/FCC/FccRules/2005/22/531/
And even domestic AM Broadcasting: many FCC rules now
refer to AM "channels" instead of frequencies, even
though the channel number and the center frequency are
the same (47 CFR 73.25, -.26, and -.27).
http://kauko.hallikainen.org/FCC/FccRules/2005/73/25/
http://kauko.hallikainen.org/FCC/FccRules/2005/73/26/
http://kauko.hallikainen.org/FCC/FccRules/2005/73/27/
====== ASSIGNMENT by ARBITRARY CHANNEL NUMBER ======
In some bands -- notably FM and TV broadcasting -- the FCC assigns
arbitrary channel numbers. These assignments are tabulated in the FCC
Rules as follows:
TV broadcasting (47 CFR 73.603):
http://kauko.hallikainen.org/FCC/FccRules/2005/73/603/
FM broadcasting (47 CFR 73.501):
http://kauko.hallikainen.org/FCC/FccRules/2005/73/201/
One additional FM Channel (200, at 87.9 MHz) has been assigned since
the original assignments were made. It overlaps TV Channel 6;
consequently, its use is limited to certain types of stations (see
footnote \1\ at 47 CFR 73.501).
Once the FCC finally established television channel assignments, the
broadcast and receiver-manufacturing industries adopted them.
But these industries didn't adopt the FM channel assignments. Why
not? There's no single reason, but I suspect that it was largely a
matter of cultural inertia: broadcasters had been using AM frequency
designations for years, and they simply continued the practice with
FM.
Furthermore, even by the late 1940s, there was still a lot of
confusion about channel assignments (as the aforementioned article by
David Ferre makes clear). Receiver manufacturers who had been
building FM radios (before channel assignments were finalized) had
been using frequency designations by default. Apparently they just
continued doing so.
This legacy too lives on to this day: we still use channel numbers for
TV and frequency designations (albeit in megahertz rather than
megacycles) for FM.
Broadcast stations take these designations very seriously: they've
become commercial brand names. AM and FM broadcast stations brand
their frequency designations, often with superficial (and
not-necessarily-accurate) descriptions: "Nifty Ninety" (really 900);
"Super 101" (really 101.3); etc.
Television stations brand their channel numbers: "Local 2";
"Virginia's 13"; "CBS-19"; etc. As brand names, these numbers are so
important that many television stations don't even use their actual
call signs. Stations even demand that CATV and DBS companies identify
them by their channel numbers, even though the actual RF frequencies
may be different.
Carrying this branding game to extreme, most television stations plan to
continue using their old analog channel numbers as their DTV "channels,"
even if they move to new channels for DTV. Receiver manufacturers have
included mapping logic to display the old numbers. Thus, for example,
WISC-TV Channel 3 will become WISC-DT Channel 50, but receivers will
display 3.1, 3.2, 3.3, etc. to identify the various video streams.
The FCC also assigns (or accepts ITU assignment of) arbitrary channel
designations for certain non-broadcast services. Examples:
Citizens Band Radio Service (47 CFR 95.407):
http://kauko.hallikainen.org/FCC/FccRules/2005/95/407/
Television Broadcast Auxiliary Service [point-to-point
microwave] (47 CFR 74.602): http://tinyurl.com/2k9d9
Cable Television Relay Service [point-to-point
microwave] (47 CFR 78.18):
http://kauko.hallikainen.org/FCC/FccRules/2005/78/18/
VHF Marine Channels (ITU RR Appendix S18):
http://www.navcen.uscg.gov/marcomms/vhf.htm
Note that the VHF Marine Channels (as mentioned in Michael Quinn's post
quoted above) were assigned by the ITU, not the FCC. The FCC incorporates
these assignments by reference.
Neal McLain
Neal McLain (nmclain@annsgarden.com)