What if we still had the old FM band today?

[thathoustonradiogeek]

I apologize for another "What If" topic, but the WHAT IF NBC RADIO & MUTUAL WERE STILL AROUND? thread got this madman geek thinking:

What if RCA hadn't lobbied the FCC to move the original FM band from 42-50 Mhz to 88-108Mhz and kept the 1940 allocation table?

We could have had an analog TV channel 1 between 1941 and 2009. Obviously, any implementation of a second FM band would have had to use frequencies other than 88-108 as those were occupied by channels 5, 6 and 7 in the old bandplan. Maybe 109 to 129 Mhz?

TV sets would have included VHF dials with the numbers 1-12 (or 1-18), and, after the DTV conversion, stations formerly on analog ch. 1 would map to 1.1, like stations between 2-6 now do.

Radio sets would have:
AM 530-1700 KHz
FM-Lo 45.1 - 50.9 MHz
FM-Hi 109.1 - 129.9 MHz

In fact, FM radios made between 1946 and 1950 had both the 45 and 88 bands to aid in the transition.

Which TV stations would have been on channel 1 (and still map to 1.1)?
WNBC-TV New York, obviously. Many stations that were the first to go on the air in their respective markets.
I can think of two: KLEE, later KPRC in Houston and WKAQ in San Juan, PR.

OK, I've rambled enough. Feel free to expand upon this or destroy it (It's OK. I'm just an ALJ*)

Reference: http://www.tech-notes.tv/History&Trivia/Channel One/Channel_1.htm

*-Average Listener Joe

 

[TheBigA]

I always thought it was strange to break up bands, like VHF TV into lo and hi. So this kind of broken FM band goes against my thinking. This is why you have to defreg a computer hard drive. Certainly from an operational point of view, it was helpful to have a contiguous FM band. So RCA actually did FM a favor. Even though their purpose was to hurt Ed Armstrong.

Another interesting "What It" would be what if the FCC hadn't mandated FM for TV audio. I've often wondered about that. I know Sarnoff didn't intend that to happen.

 

[Tom Wells]

I always thought it was strange to break up bands, like VHF TV into lo and hi. So this kind of broken FM band goes against my thinking. This is why you have to defreg a computer hard drive. Certainly from an operational point of view, it was helpful to have a contiguous FM band. So RCA actually did FM a favor. Even though their purpose was to hurt Ed Armstrong.

Another interesting "What It" would be what if the FCC hadn't mandated FM for TV audio. I've often wondered about that. I know Sarnoff didn't intend that to happen.

With AM video and AM audio, there would likely have been "picture noise" in the audio decoded.

The coverage area was larger for the old FMs, because Armstrong was competing with AM, which (in the days before all the man-made interference we enjoy now) covered large areas better tan today.
The original FM station owners were dismayed that far away stations would override their signals.
Armstrong saw no problem there. The new band, along with carefully controlled elevations, keeps signals within
markets and permits many more stations to use the available bandwidth.

If we still had the old FM band, I think we'd have a lot less stations, but the band would seem more like old-time AM
with locals, regionals, and clears.

 

[Bob1370]

TV probably would have been best served by FM being moved to where it is now (88-108 mHz) to avoid the terrible skip and ducting interference that you used to get between about 42 and 45 mHz in the lower half of the pre-war FM band. Then TV could have been located in two broad bands; an unbroken run of seven 6-mHz channels from 46 to 88 mHz, and another unbroken run further up the dial just above aviation and ham radio starting at 150 mHz and extending to 300 mHz. Lower band stations would have run maximum 100 kW ERP at 1000 feet above terrain in the densely populated Northeast and Midwest (today's Zone I) with 170 mile cochannel spacing, and 2000 feet above terrain with 200 mile cochannel spacing elsewhere (today's Zones II and III). Upper band stations would have run maximum 300 to 400 kW ERP at the same antenna heights and cochannel spacings. That would have gotten you a total of 32 channels and 1600 to 2000 allocations nationwide, which would have been more than enough to provide at least one station in every market for every commercial network likely to emerge, one or more public TV allocations per market, plus a non-network indie station or two in the markets big enough to support them. Never would have needed UHF, which would have been available for wireless phone and/or eventual broadband use.

Come to think of it, since, 1) we've cleared all the analog signals away and have a chance to redraw the VHF and UHF spectra, 2) most viewing right now is off cable or satellite, and 3) we need to clear out a lot of spectrum for broadband internet service while still providing signals to the 20-25% of people who get their TV through some kind of over-the-air service and always will, why don't we just push all the former VHF stations back to their old bands again with the power levels they used to run or higher, and move all other stations into the new channels we'd be creating below 300 mHz? We'd presumably do a new round of converter-box credits to help people retrofit their TVs, and give people and stations a set amount of time to move to the new all-VHF broadcast TV system before opening up the entire 400-800 mHz spectrum to broadband...

 

[KeithE4]

Come to think of it, since, 1) we've cleared all the analog signals away and have a chance to redraw the VHF and UHF spectra, 2) most viewing right now is off cable or satellite, and 3) we need to clear out a lot of spectrum for broadband internet service while still providing signals to the 20-25% of people who get their TV through some kind of over-the-air service and always will, why don't we just push all the former VHF stations back to their old bands again with the power levels they used to run or higher, and move all other stations into the new channels we'd be creating below 300 mHz? We'd presumably do a new round of converter-box credits to help people retrofit their TVs, and give people and stations a set amount of time to move to the new all-VHF broadcast TV system before opening up the entire 400-800 mHz spectrum to broadband...

Because the 225-450 MHz spectrum is controlled by the US Government (military, radio-location, space research, weather, with ham radio sharing the top 30 MHz). Don't hold your breath waiting for the Feds to move out of there.

Same goes with an earlier mention of 109-129 MHz. That's part of the aircraft band and it's about as close to sacred as any band of frequencies can get. That service ain't goin' nowhere!

It's a little too late to rearrange the spectrum.

 

[TheBigA]

It's a little too late to rearrange the spectrum.

And current regime at the FCC feels the best use for spectrum is broadband and cell phone. Not broadcasting.

 

[thathoustonradiogeek]

Very interesting. Thank you for your replies.

BTW, I made a mistake: the original FM band was between 42.1 and 49.9 MHz (not 45.1 - 50.9) D'OH!

What is going to happen to the frequencies that were once analog channels 2 thru 6?
I've read speculations on these boards that they may be used to expand the FM band, but only the F¢¢ knows for sure.

 

[Goat Rodeo Cowboy]

It's a little too late to rearrange the spectrum.

And current regime at the FCC feels the best use for spectrum is broadband and cell phone. Not broadcasting.

This is an interesting "would'a, could'a, should'a" conversation.

When you look at all the wonderful things being done by broadcasters with their spectrum, I would expect congress and the FCC to shrug their shoulders and mutter: "These broadcast guys haven't got a clue have they."

Check out the conversation on the Alabama Board. A big knock-down drag-out over how many farts and orgasms per hour of broadcast time are appropriate.

If a congressman or FCC Commissioner has visit Best Buy or other electronics retailer lately and taken a look at how much floor space they devote to radio receivers vs. how much floor space they devote to iPods, iPhones and wireless LAN equipment that might affect his/her thinking on how to allocate the available spectrum.

 

[MarioMania]

Would the FCC expand the FM band to 76 - 108 Mhz??

Who's using Analog 2 - 6 besides low power stations??

 

[TheBigA]

Would the FCC expand the FM band to 76 - 108 Mhz??

Who's using Analog 2 - 6 besides low power stations??

Doesn't matter. This FCC is not going to give away spectrum space to profit-making companies.

If they expand FM down to 76 (and so far they've shown no interest in doing so), it will be reserved for minorities. Then the lawsuits begin over who is a minority. In the meantime, unless they mandate including 76-87 mhz in all new radios, no one will be able to hear the new stations, just like HD.

 

[MarioMania]

Who owns the VHF low band in Analog 2-6

Is it being used by other stuff besids Low Power Stations or Tranlators??

 

[w9wi]

Who owns the VHF low band in Analog 2-6

Is it being used by other stuff besids Low Power Stations or Tranlators??

There are no analog stations in the US in those channels except for LPTVs and translators.

However, there are several dozen digital full-power stations, in markets as large as Philadelphia.

I personally believe the FM band expansion thing is dead in the water. Commercial broadcasters were fuming mad over the creation of the LPFM service, limited to 100 watts erp and with separation restrictions so tight as to hamstring the service. An expanded FM band -- which would allow the creation of additional full-market signals -- would never survive NAB lobbying. Not even if all the new signals were non-commercial.

Beyond that, expanding the FM band into some or all of the 54-88MHz band would require moving some existing DTV stations onto higher frequencies, almost certainly UHF. The Commission's recent broadband proposal suggests *discouraging* VHF=>UHF DTV moves - they're going to be VERY slow to do anything that would not only encourage, but force, stations to go in that direction.

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Going back to the original question..

I don't think a dual-band situation would have lasted. At the very least, the upper band would have been deleted in the early 1950s, as it became obvious more TV channels were required to provide a financially robust national television service. The upper band would have been converted to three TV channels, probably at the end of the second TV freeze in 1952.

I do think it would have been the higher band that would have gone away. By 1952, TV DX via sporadic-E was a fairly well-known phenomonon. Sure, sporadic-E harmed FM reception too, but FM could tolerate it a lot better. (lower chance of a station on the same frequency in the target area, and if the DX signal wasn't too horribly strong, the capture effect would cause the local signal to bury it.) Sporadic-E interference is a much bigger problem for TV than it is for FM.

Another issue would have come up in the 1970s -- to wit, we would have run out of FM spectrum. Remember, the old FM band was only 8MHz wide. If TV had expanded into the upper FM band in the early 1950s, there would have been no room for FM to expand in that direction. It could only have moved down. At the same time, two-way services had been abandoning the large antennas, electrical noise, and risk of sporadic-E by moving to high-band and UHF.

So here's a theory:

1945-1952:
FM: 42-50MHz, 88-106MHz
Fax: 106-108MHz
TV channels: 1: 54-60; 2: 60-66; 3: 66-72; 4: 76-82; 5: 82-88; 6: 174-180; 7: 180-186; 8: 186-192; 9: 192-198; 10: 198-204; 11: 204-210; 12: 210-216

1952-1975:
FM: 42-50MHz (fax is dead, and there isn't enough interest in FM to justify replacing the lost 10MHz of spectrum)
TV channels: 1: 54-60; 2: 60-66; 3: 66-72; 4: 76-82; 5: 82-88; 13: 88-94; 14: 94-100; 15: 100-106; 6: 174-180; 7: 180-186; 8: 186-192; 9: 192-198; 10: 198-204; 11: 204-210; 12: 210-216
(16-whatever: UHF)

1975-present:
FM: 35-50MHz (I think the FM band may have been more tightly packed, with 600KHz separation between stations at the same site considered adequate.)
TV: as above.

 

[trusty]

What is going to happen to the frequencies that were once analog channels 2 thru 6?
I've read speculations on these boards that they may be used to expand the FM band, but only the F¢¢ knows for sure.

We've had discussions about this - one option would be to move most of the AMs to the expanded FM band to clear out the mess on AM (Give the clears a choice.) with a 5-year simulcast overlap. I don't know if the services between channels 4 and 5 could be moved, but at least you would have 5 and 6 as a start.

But that would make too much sense. :

 

[Goat Rodeo Cowboy]

We've had discussions about this - one option would be to move most of the AMs to the expanded FM band to clear out the mess on AM (Give the clears a choice.) with a 5-year simulcast overlap.

Here is where I see it getting really nasty. (Trusty, you will recognize my example as being "live ammunition".)

Assume you have an owner who has a station low on the dial. May 550 with 10,000 watts of power, and night-time hours. And 15 or 20 miles up the road we have a 500 watt station at 1350 on the dial. (I was going to say a daytimer but I see they now have some night time power..... enough to light the inside of a refrigerator.)

How much yelling and screaming and lawsuits and courting congressmen is going to happen when the guy at 550 finds out he gets about the same thing for walking away from his AM blowtorch that the other guy gets for walking away from his refrigerator light.

I suspect the heavy-thinkers in spectrum allocation will look at all the "can of worms" situations across the country and just bide their time until the wheels someday fall off the wagon for AM radio.

 

[trusty]

Blowtorch or refrigerator light, the owners get to move to FM, and the 5-year simulcast period provides plenty of promotion time (like the AM expanded band or digital TV). Also, there are some FM channels now (I believe 92.1 is one of them.) that lower max power levels allows for shorter spacing. A similar setup can be made for the FM expansion band.

540-1700 allows for 116 AM channels.
77.3-87.9 (ch.5-6) allows for 54 FM channels. 55.3-71.7 (ch.2-4) allows for 83 FM channels. Total = 137. (There are non-broadcast services on 71.9-77.1 that may have to be moved to make the new FM dial contiguous.)

(I'm counting on my fingers here, so I may be off 1 or 2. )

You and I win - especially with the lousy AM ground conductivity in our area.

 

[w9wi]

Also, there are some FM channels now (I believe 92.1 is one of them.) that lower max power levels allows for shorter spacing. A similar setup can be made for the FM expansion band.

This is no longer true.

At one time, twenty commercial FM channels were reserved for Class A stations, at the time limited to 3kw/300'. 92.1 was indeed one of those 20 channels. Lower "classes" of station indeed allow shorter spacing due to lower powers. The other commercial channels -- other than the 20 reserved for Class A -- were reserved for Class B (50kw/500') or C (100kw/2000') depending on geographic zone. You couldn't have a Class A station on a non-Class A channel like 92.3, and you couldn't have a Class B station on a Class A channel like 92.1.

A major change in the FCC regulations in 1980 erased this distinction. Today, you can have a station of any class on any channel. There are Class C stations on 92.1 and Class A on 92.3. Spacing in a given area is not determined by the channel, but by the mix of classes of stations in nearby areas on that and nearby channels.

Which doesn't mean you couldn't reimpose that kind of restriction in a new FM expanded band. But see below: I don't think you're going to see FM expanded.

(There are non-broadcast services on 71.9-77.1 that may have to be moved to make the new FM dial contiguous.)

72-76 to be specific.

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How much yelling and screaming and lawsuits and courting congressmen is going to happen when the guy at 550 finds out he gets about the same thing for walking away from his AM blowtorch that the other guy gets for walking away from his refrigerator light.

Agreed fully.

This is, IMHO, much of why we invented IBOC rather than using the existing Eureka digital radio system. AM stations -- especially the ones with limited coverage near the top of the dial -- are not serious competition for established FMs. Allow these AMs to acquire a competitive FM signal* and they dilute the competitive advantage of the established FMs. The existing FMs won't allow it.

*(or on the same DAB platform as the major FMs)

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That and, and I can't emphasize this enough, there ARE DTV stations in channels 2-6 and it will not be a trivial task to remove them. There is nowhere for them to go besides UHF, and the FCC doesn't want them there. (Heck, I almost wonder whether the Commission would rather convert the FM band to three TV channels if it meant they could auction TV channels 49, 50, and 51?) :

 

[trusty]

Thanx, w9wi, for the update, and I agree, It's just that any thread that begins with "What if..." calls for ideas, opinions and suggestions, and not necessarily facts, But, we do need a framework to "frame' the ideas, etc.

At the risk of getting more off-topic, but only for a quick answer, how is Canada moving its AMs to FMs?

 

[w9wi]

At the risk of getting more off-topic, but only for a quick answer, how is Canada moving its AMs to FMs?

Canada doesn't have a formal program for doing that. (Mexico does, but I think it would be safest for me to defer to David Eduardo for details)

Canadian policy is to consider economic impact on other stations when considering whether to authorize a new station. A new station won't be authorized simply because a frequency is technically acceptable & someone wants it. As a result, there are still plenty of decent FM channels available in rural areas and occasionally even in larger communities. (there are still three available in Brandon, Manitoba, so if the city's last AM station ever wants to move, there's room.) They have also decided to allow the use of 3rd-adjacent channels. For example, in Calgary there are full-power stations on 98.5 and 99.1. Stations would not be allowed that close together in the U.S.. Of course, this opens up more channels. Finally, treaty does not require Canada to protect U.S. stations from interference if that interference takes place only in Canada. (they are required to prevent interference that falls in the U.S.) Recently they've begun taking advantage of this, authorizing stations on channels that would not be usable if the new station was in the same country as the old one. For example, a 104.1 was authorized in Vancouver, just across the border from a 104.3 in Bellingham, Wash..

They do have a regulatory mechanism for modifying an AM license to specify operation on a FM frequency. In the U.S., you can't do that -- once an AM station, always an AM. If you want to move to FM you either have to take out a license for a new FM or buy an existing one. The AM license continues to live unless you choose to surrender it. In Canada you can apply to modify the technical parameters of your AM license to specify operation on an FM frequency. You do have to compete with other applicants, including some who may wish to build a completely new FM.

As a result, when a Canadian AM station moves to FM the AM frequency dies. In the U.S., it doesn't -- and the licensee tends to try to keep the AM running with some other format.

 

[nd2023]

I wish we had 20 mHz of spectrum centered around 50 mHz. More e-skip!

 

[MarioMania]

They do have a regulatory mechanism for modifying an AM license to specify operation on a FM frequency. In the U.S., you can't do that -- once an AM station, always an AM. If you want to move to FM you either have to take out a license for a new FM or buy an existing one. The AM license continues to live unless you choose to surrender it. In Canada you can apply to modify the technical parameters of your AM license to specify operation on an FM frequency. You do have to compete with other applicants, including some who may wish to build a completely new FM.

As a result, when a Canadian AM station moves to FM the AM frequency dies. In the U.S., it doesn't -- and the licensee tends to try to keep the AM running with some other format.

Then people in Canada could get US Full Powered AM's at night then