FM broadcast band might be expanding

[Bill, KD0HG]

Radio in the future for TV channels 5 and 6?
There's been plenty of talk in the engineering community about expanding the FM band downward into the 76-88 MHz band now occupied by TV channels 5 and 6 - but until now, no sign that the FCC is taking the suggestion seriously. But buried in the FCC's Report and Order on its broadcast ownership proceeding earlier this month were some hints that someone in the Commission thinks the idea might be viable. Mullaney Engineering filed a formal proposal with the FCC last year laying out such a plan, and the Report and Order says "this proposal could yield tremendous opportunities for new entrants, and we seek comment on it."

Who knows- ?
 

[W4EWH]

If it's real, it's also really short-lived: noone in the business would bid on that spectrum for broadcast:

• It would take years to get compatible receivers into automobiles. FM and AM both live and die by "drive time", which means getting new receivers into cars, and buyers don't like to pay for car radios.
• The broadcast industry is undergoing unprecedented cost-cuttings and consolidation, and there just isn't enough "product" to fill new allotments. As it is, every major market has three or four stations owned by the same chain. None of these chains (Clear Channel, etc.) wants to have more competition.
• The FCC wants to auction off all the VHF spectrum being vacated by analog TV, and land-mobile will bring a lot more money.
• Expanding FM below 88 MHz causes image problems: the standard 10.7 MHz IF in FM receivers would start producing images if stations below 88 MHz were licensed, and the existing band is only 20 MHz wide for exactly that reason. Don't assume "new" technology would solve this problem: "parts count" is everything in the consumer-electronics business, and automobile manufacturers are the worst of all when demanding engineers cut every corner.
• Satellite is too well established as an alternative. There'd probably be a score of lawsuits from Sirius et all, who paid out all that dough for their geosat allotments.¹

My 2¢.

73, Bill W1AC

1.) The inventor of Geostationary satellites died yesterday: Arthur C. Clarke, the noted science-fiction author, was 90.

[David, K3TUE]

FM broadcast down to 76MHz is common around the world.  Receivers being sold in the US right now have such capabilities that can be enabled with the click of a menu option.  I've been buying them for a few years now.  The space is hardly worthless.

Long live terrestrial radio.  I have no need for satellite radio.

[Tom WA3KLR]

My understanding is that the Philadelphia TV station on channel 6 (ABC affiliate) will transmit DTV on the channel after the plug is pulled on NTSC.

[KA8WTK]

Years to get ready? HA! I'm all set!
My SX-42 will tune FM stations from 55 to 108 megacycles.

[Bill, KD0HG]

And my S-36A.

[WB2EMS]

Seems like a natural space to accommodate the Low Power FM folks, and get some community radio going again.

[Opcom]

Got a couple of R-220's and a Nems-Clarke surveillance receiver.. ready for it!

[David, K3TUE]

Love the LPFM/Community radio idea.

[k4kyv]

It would certainly make as much sense to expand the FM band as it did to expand the AM band a decade or so ago.

But if the FCC is as slow about it as it was with the AM expansion, we might get to listen to the expanded FM band on our bedside radios at the nursing home.  The AM expansion was approved at WARC 79, but it was not until the late 90's that stations began to populate the new channels.  It took almost 20 years of bureaucratic rambling and debating exactly how the new frequencies would be deployed, before a band plan was finally approved.  And it ended up being just more of the same old same-o.  A waste of spectrum IMO.

As for image frequencies, it would be up to the manufacturers to build clean receivers.  There are other conversion schemes besides the longstanding antenna-mixer-10.7 mHz i.f.- detector-audio circuit lineup.  Many of the amateur radio appliances to-day start off upconverting to a 1st i.f. in the 60 mHz range to eliminate the image problem.  Even a selective front end before the 1st mixer would do the trick with the 10.7 mHz i.f. configuration.

[Bill, KD0HG]

21 Mhz is also a relatively common IF freq.

I wonder if that's a throwback to the early TVs that also used 21 MHz.

[Tim WA1HnyLR]

I have always thought that it would be a natural to expand the FM broadcast band down 10 Mhz  with the demise of VHF television. It is not certain how many  tv stations with highband VHF channel assignment will be keeping the channel bud broadcasting in HD. It is much more dificult to broadcast an HD TV signal on the lowband VHF channels because the percentage of bandwidth to frequency of operation is too great. One must have a virtually flat bandpass over the tv channel in order for the system to work correctly. Therefore I belive the lowband VHF tv channnels will be reassigned. Back to the matter at hand. Here is what I propose. Make the assignment from 78-88 Mhz a digital only broadcast system a high bit rate stream. The deployment of so called HD fm and HD am by such broadcast moguls like Cheap Channel have realy trashed or undermined the overall quality of service especially the AM broadcast band. You cant intertwine the two different transmission modes the way it is done without compromizing both services. A high quality digital only stream is much more robust in its ability to deal with interference . I understand that there is a high quality DRM system that is very good. It requires 100Khz of spectrum. I propose that there 100 new channnels to fit within the aditional 10Mhz slice added to the bottom of the FM broadcast band. It would be up to the FeeCCee to require that all fm radios over a certain price range would automatically switch of it's detection scheme over to digital when tuning below 88.1 Mhz. This would be seamless tuning for the listener. It would appear to be all one  big band. In terms of getting an assignment with the new band. A.n existing FM broadcaster may apply for a channel and similcast  his analogue FM progrmming. He may operate parallel programming for five years. After this time period the broadcaster would have to make a choice which service he was going to keep. It would be hoped that over a period of time the popularity of good digital broadcasting would open up enough spectrum in the FM broadcast band in order to place the second phase into operation.The spectrum from ,88-98Mhz will have areas open up for digital broadcasting. The end result will to eventually reserve 98-108 for FM only broadcasting. There must always be a place for mom and pop radio stations,low power community broadcasters and those broadcasters that would rather remain on FM.As for the AM radio service . Scrap the idea of intermingleing any digital signals in the band . Restore fuller fidelity again. The problem with AM broadcasting is in the method of detection. NOT the transmission mode. A good dual sync detection scheme followed by digital signal processing with make a huge difference in receiving GOOD  AM broadcashing in the car. Now that I have made a rediculously long old buzzard transmission ,I had to launch the thought after reading Bills post. I had been thinking of this one for  some time now.
Tim WA1HnyLR