Re: Walter's Telephones [Telecom]

Not particularly. Home shopping stations and satellators meet the PICON standard as the FCC interprets it today.

The FCC does not consider the nature of the programming in making its licensing decisions, and has not used the "comparative hearing" system in two decades. If an application is technically feasible, not mutually exclusive with other pending applications, and would not cause the licensee to exceed the station ownership limit in the market, then it will be granted.

Actually, 0.8 MHz is the spacing. FM stations are required to protect first-, second-, and third-adjacent channels, and the standard for second- and third-adjacent spacing are the same. See sections 73.207,

73.213, and 73.215 of the FCC Rules. Other taboos include the 10.7 MHz IF (intermediate frequency) used in superheterodyne FM receivers and various (mostly obsolete) requirements for the protection of nearby analog TV channel 6 operations.

Actually, the spacing restrictions are primarily political/administrative; stations could be spaced more closely (in frequency and in space) without impinging on any technical limitations of the FM broadcasting system. FM, especially here in the crowded northeast, is already interference-limited. (Modern FM receivers are as sensitive as they can possibly be: low-cost receivers can demodulate signals in the nanovolt range, deep into the thermal noise floor.)

A very great deal less than they were ten years ago.

Actually, many low-end Radio Shack tuners did include TV, since the electronics to tune mono wideband FM is the same for 81.75 MHz as it is for 107.9 MHz. (Plus, most IC-based FM tuners are made for sale in Japan as well as the U.S., so there is a simple strapping option on the chip to select either the Japanese or the ITU FM band. The Japanese FM band overlaps Region II channels 5 and 6.)

None of those stations are worth remotely what they were valued at back then. A full-class-B station in New York is in the process of being sold for $45 million; a station in Philadelphia would have a "stick value" much less than that. CBS recently sold a group of three full-class-C FMs in Denver for $19.5 million total. You need to understand station prices in the late 1990s as part of an asset bubble, inflated by easy access to credit and the rapid consolidation of the industry after passage of the Telecommunications Act of 1996. (Sound familiar?)

-GAWollman

Interestingly, at least one manufacturer did make a TV-audio receiver

- Tandy/Radio Shack.

1988: 12-613 A$49.95 AM/FM/VHF TV Sound Radio "Don't miss your favorite program when your (sic) away from your TV" Realistic(R) Pocket Porta-Vision with VHF-TV sound. Ceramic filter cuts interference on FM and TV CHs 2 to 11. 5.6cm speaker, earphone. Requires 9V battery.

Not to mention that channel 6 video sat right in the 6m band.

***** Moderator's Note *****

The Six-Meter Amateur band is from 50 to 54 Megahertz. The old TV Channel 6 was from 82 to 88 Megahertz. Since the FCC once sent me a letter about a Television Interference complaint from a man who lived a block or two away from me, I remember having to look up the TV assignments - pre internet, mind you, when we had libraries that were only open during snowstorms - and calculating the harmonics of my Eight megahertz oscillator to diagnose the problem.

Long story short, I don't think TV Channel 6's video is near the Six Meter ham band.

My feeling is that since they broadcast audio on 87.7 FM a few weeks ago, they should continue to be able to broadcast audio on 87.7 FM now _without_ jumping through numerous licensing hoops to be allowed to do so.

Or are you saying that there's another organization chumping at the bit to broadcast FM at 87.7, and, that frequency is far enough away from others, and, usable? (Some other people suggested 87.7 actually isn't 'truly' on the FM dial being too low, but dials get it anyway.)

Another poster noted radio stations aren't as valuable as they used to be. In the Philadelphia market there has been a fair amount of turnover and format changes. A few stations seemed to take in very "low-end" advertisements (semi-scams, such as miracle health supplements) That seems to me to indicate there isn't as much value to the station because they're desperate to take crappy ads.

***** Moderator's Note *****

Lisa, the FCC isn't likely to allow channel six to be used for FM broadcasting. Here's why:

1. Sauce for the Goose, Sauce for the Gander: if the former holder of the Channel Six license gets to bring in revenue from FM broadcasting, then the former holders of other channels are entitled to do it too.
2. It's true that NTSC TV stations broadcast their audio using FM, but they're only allowed to use 25 Kilohertz deviation, not the 75 KHz which is standard in the FM broadcast band. That's why when listerners tuned their FM radios to Channel Six's audio, it would always sound quieter than regular FM broadcasts: NTSC is a different system, with different design criteria, and is not suited to the transmission of high-fidelity music.

So, who gets their wrist slapped when that spacing is violated? :-)

Here (San Francisco Bay Area, San Jose to San Francisco, Oakland, Santa Rosa), the FM stations are mostly at 0.4MHz separation but there are some commercial stations spaced at only 0.2MHz.

I didn't realize that until the station I followed for 20 years just changed its playlist and I had to seek a replacement. The best list of SF Bay Area FM stations is here (sorted by frequency):

And since I built an SCA decoder into one of my FM tuners, I also recently checked to see how many stations had alternate programming: a LOT.

***** Moderator's Note *****

SCA is an acronym, which stands for Subsidiary Communications Authorization: it's a system that allows FM station to "piggyback" low-quality analog signals on their regular broadcast channel, for reception only by licensees who have special receivers. It's usually used for Muzak or similar background-noise services, although I know a station in Boston which uses its SCA allocation to carry "The Physicians Network", which is a never-ending source of amusement if you listen to the ads.

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I appreciate Garrett's corrections. But I stand by my underlying points:

- The Channel 6 situation that Lisa described worked ONLY for analog (pre-DTV transition) broadcast stations operating on VHF Channel 6, due to the proximity of Channel 6 (82-88 MHz) to the FM broadcast band (88-108 MHz). In the Philadelphia market, that was WPVI-TV, but the same situation existed throughout the USA and Canada.

- Any analog television broadcast station licensee could have applied for (and possibly have received) an FM broadcast station license for the purpose of to transmitting its audio signal in the FM band. Apparently, none (or very few) did, presumably for financial reasons.

- Any digital television broadcast station licensee could do the same thing today.

As for radios with TV tuners, are there any radios available with TV tuners capable of tuning the audio of post-DTV transition digital TV stations? What about car radios?

Neal McLain

The Bay Area is a hundred miles long from north to south, with mountain ranges on both sides providing terrain shadowing that allows closer spacing. It's not a typical radio market by any stretch. Even co-channel class-As need only be spaced 112 km apart!

New York is a more typical example, with class-Bs at 92.3, 93.1, 93.9,

94.7 (Newark), 95.5, 96.3, 97.1, 97.9, 98.7, 99.5, 100.3 (Newark), 101.1, 101.9, 102.7, 103.5 (Lake Success), 104.3, 105.1, 105.9 (class B1, Newark), 106.7, and 107.5. (With the exception of the 94.7, all transmit from the Empire State Building, and most are on the master antenna there.) The second-adjacents are, for the most part, way out in the suburbs, with the exception of a few stations that are "pre-'64 short-spaced" and don't have to observe the second-adjacent spacing restrictions (which were changed in 1964 when the current system of FM classes was introduced).

-GAWollman

Actually, many of them did -- indeed, most television operations were started by radio stations, rather than the other way around. The FCC's policy in the 1970s and 1980s was to break up such combinations, so the stations in radio-TV combination could not be sold to the same buyer, and no new combinations could be created. (The same thing was true of newspaper cross-ownership, which is still being fought over in the courts, much to the detriment of both broadcast and print journalism.)

There are expected to be some relatively soon, once the ATSC-M/H standard is implemented by stations and consumer-electronics companies. (Qualcomm MediaFLO, used for video-on-cell-phone systems by both Verizon and thenewatt, uses an incompatible system, on former channel 55.) There will be broadcasters testing transmissions to prototype handheld devices later this year -- but it's probably still going to be targeted more towards the cell-phone audience than the portable radio audience. The existing ATSC system requires too much computational heavy-lifting to be decoded by limited-battery-life portables.

-GAWollman

"chumping"?

WPVI is still on channel 6. There are some experiments underway at another channel-6 station that kept its old channel, WRGB in Schenectady, to determine how compatible standard wideband FM broadcasts are with ATSC digital signals. WRGB is currently broadcasting in FM on 87.9 MHz (rather than 87.75), although observers are still trying to figure out what the FCC has actually authorized for this experiment.

In major markets, there will be (broadcast television) stations that wish to operate on channel 6, assuming the FCC doesn't decide to reallocate channels 5 and 6 to radio broadcasting, as it is currently considering.

-GAWollman

Why should they get any such _special_treatment_?

Do you believe that -every- Television broadcast station should continue to be able to broadcast audio at the sub-carrier frequency of their old Analog license?

That's right. it _is_ *outside* the official FM band. *NOBODY* can, or _ever_could_ get a license for an audio-only FM transmitter on that frequency.

In point of actual fact the TV station didn't broadcast on _that_ frequency either. TV stations broadcast a single, _complex_, signal -- an amplitude- modulated, single-sideband, vestigial carrier signal, to be precise -- one component of which is a medium-deviation frequency-modulated 5.75 MHz 'tone'.

By 'sheer coincidence' -- since -this- 'tone' (technically a "sub-carrier") is of constant amplitude -- it "looks" similar enough to a conventional broadcast band FM signal that a conventional FM receiver can extract the audio from it.

There is _NO_ guarantee that -any- particular "FM broadcast band" receiver will, in actuality, be able to tune 'far enough' outside the FM broadcast band to pick up that broadcast.

The -only- reason it works, _when_ it does, is 'cheap manufacturing' of the receiving devices.

And, the FCC does _not_ regulate radio use at the Newfoundland aviation facility that was the traditional starting point for trans-Atlantic flights via Thule, Greenland.

Thus, no sauce for Gander. (unless the Canadians order it, it's _their_ base :)

[sneck]

Channel _one_, back when it existed, included the upper half of the spectrum now allocated for 6m amateur operations.

***** Moderator's Note *****

What was Channel one's allocation? When was it discontinued, and for what purpose?

Bill Horne

Sure they can/could -- so long as they called it "low power TV". Near as I can tell from examination of the FCC rules, there is no requirement for an LPTV licensee to actually transmit a video signal.

Actually, a reduced-carrier, vestigial-sideband signal, to be accurate as well as precise.

Not really. The standard design for full-power analog TV transmitters over the past six decades has been to modulate and amplify the audio carrier separately and combine them after the final amplifier. This allows the audio carrier to be amplified using a more efficient (nonlinear) class-C amplifier.

Nonsense. 87.7 MHz is in the European FM band, so most tuners can receive it. (In the UK, for example, it is used for "restricted service licence" transmitters at special events.)

-GAWollman

,

Actually, the aural carrier is a discreet frequency-modulated carrier located 4.5 MHz above the visual carrier. The upper sideband of the visual carrier is cutoff-filtered at 4.2 MHz to avoid interference with the aural carrier. The aural carrier is phaselocked to the visual carrier to maintain a precise 4.5-MHz spacing between the two carriers. This is shown graphically in the Wikipedia article at

The 4.5-MHz offset between the two carriers simplifies the design of television receivers. Since the aural carrier is always 4.5 MHz above the visual carrier, the audio detection circuits can be fix-tuned to that frequency. Most receivers sold during the earlier years of the industry used this "intercarrier" design.

This technique also works if the 4.5-MHz aural carrier is *below* the visual carrier. In 1975, Time, Inc. launched its fledgling pay-TV service called "Home Box Office" (HBO) by satellite. Over the next few years, CATVs across the nation started carrying it, and numerous manufacturers came out with devices to secure it from unauthorized reception by basic-only subscribers.

One manufacturer came up with the bright idea of inverting the channel, with aural below visual. It offered a midband modulator (channel 17 as I recall) to generate the inverted channel, and a simple settop box that reinverted the channel back to normal and converted it to a standard VHF frequency.

It quickly became obvious that inverting the channel was not a secure scrambling technique. Intercarrier TV sets (which, in those days, accounted for the vast majority of consumer sets) demodulated the audio just fine.

That left CATVs with only one line of defense against signal theft: the fact that HBO was carried in the midband, out of tuning range for the 12-channel TV sets of the day.

But those TV sets all had "turret" tuners -- those big clunky things that switched different circuit boards into the circuit, one for each channel. It didn't take long for local TV shops to start offering "Free HBO" circuit boards.

Neal McLain

***** Moderator's Note *****

I lived in Santa Barbara, California during 1978 and 1979, and the cable TV company had a "Channel 100" service, which was one of the early "closed system" offerings. The actual frequency used was just below TV channel 7, in the public safety/industrial band usually used by taxicabs, police, and fire departments. "Channel 100" was from 168 to 174 MHz, just below VHF TV Channel 7 IIRC.

Since Channel 7 wasn't in use on the cable system, the local TV shops started to modify sets so that Channel 7 was actually "Channel 100": all they had to do was squeeze the inductor on the turret tuner, so that it would cover the lower range.

The cable company was understandably upset, but the modification became common knowledge, so they had to add an interfering signal to the Channel 100 frequency band, and then give out filters to Channel 100 subscribers to notch out the interference and restore the channel to viewable condition. Of course, the local ham club had a contest to see who could design the best "Channel 100" filter, and they came up with a coaxial cavity model, constructed from copper pipe, which did a better job than the "LC" filters provided by the cable company!

Persons who will not be named took it on themselves to start a cottage industry, manufacturing and distributing channel 100 filters. Said persons soon discovered that the available market was limited because they depended on word-of-mouth advertising, and abandoned the effort.

By the time I had migrated to Boston and taken up residence next to Northeastern University, where I was attending, HBO had become prominent, and it was using the Multi-point Distribution System to send signals to local cable head-ends. Once again, ham operators found a way: a common child's toy of the day - a circular snow slide - turned out to make an excellent parabola for a ~2 GHz dish receiver. As it happened, I didn't have a line-of-sight to the Prudential tower, where HBO's transmitter was, but I found out that the building across the street made an excellent near-field reflector. Stiller and Mira never looked so good.

Of course, everything finally went to satellite, so only those who could afford TeleVision Receive Only (TVRO) satellite receivers, and who had space for them, could get it directly. Since cable TV took a while to get to rural areas, the 3-meter-diameter dishes soon became known as "The State Flower", and their popularity gave HBO another problem, which was that satellite TV receivers, already equipped with Polar mounts that could track any bird in the Clarke Belt, could poach their signal. Inevitably, scrambling became the norm, and now the few remaining satellite receivers still in use are limited to viewing occasional TV feeds from news crews at special events, back-hauls of network traffic, and some specialized programming, such as medical training films and over-the-air classroom shows intended for Alaska or other remote regions.

Interestingly enough, there's a ham connection in TVRO as well: one of the better-known firms in the field is the R.L. Drake Company of Miamisburg, Ohio, which used to manufacture a line of Amateur radio transmitters, receivers, and transceivers. The sets are still prized for their excellent audio quality and layout - yours truly owns a Drake TR-4 - although they're also in demand by "Outbanders", the citizens-band operators who modified old ham gear to operate in the relatively quiet areas beyond the official CB frequencies.

Ah, the memories.

Bill Horne

(a) I don't think WPVI-DT's competitors would agree.

(b) WPVI's owners (The Walt Disney Company) would not be able to obtain a license to broadcast an FM signal at 87.7 (or 87.75) no matter how many "numerous licensing hoops" it jumped through.

(c) Even if it could, it wouldn't want to. A carrier at that frequency would interfere with (i.e., utterly destroy) the WPVI-DT signal now operating on Channel 6.

WPVI-DT operates on the same Channel 6 that WPVI-TV formerly used. But the audio signal is now encoded digitally as part of the same digital stream that carries the video. There is no separate aural carrier at 87.75 MHz. See (c) above.

BINGO! That's precisely the point of this whole Channel 6 thread- within-a-thread.

Well, then, don't listen! For years, you've been making that same complaint about advertising-supported non-broadcast CATV channels. If you don't like the ads, don't watch the channel!

Neal McLain

Bill:

Here's the definitive Channel 1 story, written by John W. Reiser, former Chief of the International Bureau of the FCC:

Neal McLain

Some history of channel one, written by a former FCC staff member, is at

Harold

Note: I have to correct myself. At one point, Channel _2_ sat on what is now the entire 6m ham band. Then Channel 1 occupied those frequencies for a while. Then it was moved below 50 MHz. (making life more fun, this was all 'shared use' spectrum. :)

Then channel 1 'went away' (the 'easiest' way to avoid having to 'renumber' the other channels).

When?? *GRIN*

It (and the other VHF channels -- did you know that there were _VHF_ channels up to 'channel _19_' at one time?) moved around. 'Gory details' in the Wiki article cited below.

Channel 1 was moved from it's original assignment (44-50MHz) to

50-56MHz, to make room for the original 'FM broadcast band'. This was 1940.

That's easier. May, 1948. However, thy were out of the now 6m Ham frequencies in 1946.

In modern parlance, to 'rationalize' spectrum usage. :) *LOTS* of stuff was moved around at that time. TV spectrum got juggled in 1940,

1946, _and_ 1948 (minor tweak). the '46 changes gave us the current channel allocations, '48 gave TV the -exclusive- use of that spectrum space (and eliminated channel 1).

See the Wikipedia :)

Since Harold Hallikainen and I both cited the same "Whatever Happened to Channel 1" article by John W. Reiser, I'd like say a few words about John.

I worked for John during the 1950s when I was attending the University of Michigan in Ann Arbor. During the regular University academic year, John was Chief Engineer at the Speech Department's Television Studio, a lab studio for training television production. It wasn't much of a studio -- just a classroom with a couple of monochrome vidicon cameras. But it did give students a chance to practice before live cameras, and to learn elementary production techniques.

I was sort of John's assistant, mostly assigned to setting up equipment for classes, and "shading cameras" during class. In those days, "shading cameras" was an important function because video cameras didn't have any of the automatic brightness/contrast adjustment features now common. I spent many an hour sitting there tweaking signal levels during class sessions.

During the summers, John was Chief Engineer at the Radio Department at the National Music Camp in Interlochen. The Department's job was to record every major concert or recital performed by campers (students) or faculty. We assembled broadcast programs from these recordings (shipped to radio stations worldwide); made LP recordings of select performances for sale to campers (or their parents); ran PA systems for public functions; and maintained all sorts of electronic gear.

I was one of a group of college guys that spent several summers as radio engineer at the Camp. Pay wasn't very good, but the job included room, board, and free use of recreational facilities. The camp was located between two lakes (hence the name Interlochen), so there was an endless variety of water sports. And then there were all those female college students... uh, I guess I better stop here.

Anyway, that's how I spent most of my college years: working for John in Ann Arbor during the academic year and working summers for John at Interlochen.

The last time I saw John was at the 1995 Society of Broadcast Engineers Convention in New Orleans, where John was guest speaker at the Awards Banquet. I wasn't sure he'd remember me, but indeed he did, and he even acknowledged my presence in the audience during his talk.

The Quarter Century Wireless Association has a bio of John at

Neal McLain

There is no "special" treatment, per the circumstances described in prior posts..

IRELEVENT. We are talking about ONE SPECIFIC channel.

Doesn't matter.

The audio portion of TV's Channel 6 was receivable on any FM radio, either cheap ones or good ones, tube or IC, for _decades_.

The _only_ issue that could matter is if someone else desires use of that particular frequency. Others have said it cannot be used because it would cause interference to other FM stations close in frequency.