Radio Free Capitol Hill

Jesse Walker | June 22, 2007

Good news for fans of neighborhood radio: Reps. Mike Doyle (D-Penn.) and Lee Terry (R-Neb.) introduced a bill yesterday to loosen the government's restrictions on starting independent, low-power stations in urban areas. Sens. Maria Cantwell (D-Wash.) and John McCain (R-Ariz.) sponsored the Senate's version of the legislation. (Yes, McCain. Initially a vocal opponent of low-power radio, he did an about-face several years ago; these days he's pretty good on the issue.)

Here's what the bill does:

* It repeals the Radio Broadcasting Preservation Act of 2000. This misnamed law, pushed by the National Association of Broadcasters, hobbled the FCC's plan to license new low-power stations by effectively limiting the available slots to the countryside. (Fun fact: In the House, every Republican except Ron Paul and Ed Royce backed the bill.)

* Within carefully defined limits, it allows stations to transmit closer to each other on the FM band, thus making room for more broadcasters.

* It asks the FCC, when issuing licenses, to give low-power projects that offer their own programming the same consideration given to "translator" stations that retransmit signals originating elsewhere.

The law is called the Local Community Radio Act of 2007. The folks at the Prometheus Radio Project offer some tips on helping it pass here.

Update: McCain isn't the only presidential candidate backing the bill. I just got an email from Ron Paul's legislative director letting me know his boss is signing onto it as well.

Comments

|6.22.07 @ 11:03AM|#

They say you better listen to the voice of reason
But they don't give you any choice 'cause they think that it's treason
So you had better do as you are told
You better listen to the radio

Hard Harry|6.22.07 @ 11:22AM|#

Hier we live in a dead decade...

|6.22.07 @ 11:26AM|#

Yes, McCain. Initially a vocal opponent of low-power radio, he did an about-face several years ago; these days he's pretty good on the issue.

At least as long as nobody's using LPFM to say anything, you know, political.

|6.22.07 @ 11:27AM|#

* Within carefully defined limits, it allows stations to transmit closer to each other on the FM band, thus making room for more broadcasters.

Jesse,

I've always been curious about something. All the way back in 1980, I was playing around on my dad's new-fangled "digital tuning" stereo, and I noticed there was a setting you could change so that instead of skipping .1-.3-.5-.7-.9 on the FM band, it went .1-.2-.3-.4-.5 etc. I asked my dad about this at the time and he said that in the future there would be additional stations on those in-between frequencies. Was there ever a plan for that? I've never seen a stereo since then with that setting.

Jesse Walker|6.22.07 @ 11:33AM|#

Elvis: I've never heard of a plan to let stations broadcast that close together. That doesn't mean it never happened -- there's a lot out there that I've never heard of -- but it seems pretty unlikely.

wsdave|6.22.07 @ 11:41AM|#

Jesse and Elvis,

Could it be that somebody was actually thinking ahead? Ahead to a day when digital technology could fine tune well enough to filter out the other stations? Perhaps using an inaudible carrier signal?

Naw; that would be the government like thinkin' and stuff. Never happen.

ed|6.22.07 @ 11:45AM|#

The "government" didn't discover radio waves and they don't manufacture tuners. They merely get in the way of those who did and do. It's their job.

|6.22.07 @ 12:23PM|#

Is there room between stations in most urban areas. In NYC it is very hard to find an open spot for an FM transmitter for an ipod. Every frequency is taken or has interference from a powerful station close by (ex. 92.1 is not clean b/c of 92.3 signal.)

|6.22.07 @ 12:41PM|#

People still listen to broadcast radio?

|6.22.07 @ 12:49PM|#

As I understand it, in the Americas FM stations broadcast on the odd decimals, like 93.1, 93.3, 93.5...
Outside the Americas, they broadcast on the even decimals, like 90.0, 90.2, ...
I believe it's just one of those conventions that mattered when the industry and technology were new.
LPFM could probably be allowed to broadcast on the even decimals, so long as they are at least 0.2 MHZ from a local broadcaster -- but you'd need a new and/or non-digital receiver to pick up the signal, I think.

...Any actual experts out there with better info?

Jesse Walker|6.22.07 @ 1:01PM|#

Me: It depends on what city you're in. Offhand I don't remember whether New York is one of the places that will be able to get new stations under the new law.

Virgil: Thanks for bringing up the international angle -- that's a much more plausible explanation for Elvis' old radio.

No one's talking about letting the new stations broadcast on the even decimals. They're talking about letting them broadcast on odd decimals even if someone else in the area is broadcasting on another odd decimal that's closeby.

NP|6.22.07 @ 1:43PM|#

"This misnamed law..."

lol

|6.22.07 @ 3:00PM|#

"Elvis' old radio"?
Did I miss a link somewhere? I don't know the reference.

Robert|6.22.07 @ 3:06PM|#

Stations can fairly easily be squeezed in tighter, as shown by NOAA weather stations on 162.425 MHz, 162.55, and 162.675. I think they're FM.

And you can also squeeze in quite a few analog subcarriers. For that matter, the medium wave AM BCB could be opened to SSB.

|6.22.07 @ 3:09PM|#

Ahh, I see.

You are referring to the earlier comment from dead_elvis about his Dad's radio from the 1980s.

|6.22.07 @ 5:13PM|#

FM radio stations in the US all operate at odd
frequencies to avoid harmonic interference.

Harmonics are - usually - even multiples. If
the primary is an odd number ending in, say
.7, the first major harmonic will end in .4

No primary frequencies end in .4 and this will,
in theory, reduce harmful interference.

---

Tomorrow, June 23, is the start of this years
Amateur Radio Field Day. Look for your local
Amateurs operating portable stations at parks
and other public facilities. Stop by and
say "Hello!"

|6.23.07 @ 1:32PM|#

Tomorrow, June 23, is the start of this years
Amateur Radio Field Day. Look for your local
Amateurs operating portable stations at parks
and other public facilities. Stop by and
say "Hello!"

Sounds like a bunch of geeks to me. Fun, interesting geeks probably, but still with the order geekera.:-)

|6.24.07 @ 5:12AM|#

Regarding Robert's comment:

(I'm not an "expert" on radio by any means, though not far from it...)

Yes, it is true that FM stations can be squeezed quite tightly together - in various parts of the VHF spectrum, the spacing between channels is typically either 12.5 kHz or 15 kHz. (That would correspond to 0.0125 or 0.015 on your FM dial). Stations can operate on adjacent channels without interfering with each other, although they can't get much closer than that (below 10 kHz spacing, the stations will begin to interfere with one another).

However, these are narrow-band FM transmissions. FM radio in the 88-108 MHz band is wide-band FM, to give significantly greater fidelity (audio bandwidth), as well as being transmitted in stereo (two simultaneous signals). This requires that the FM signal occupy a significantly larger chunk of frequency space (about a factor of ten).

(To give a basic explanation... an FM signal takes up a finite amount of frequency space(called the bandwidth) around a central frequency. You start with an informationless carrier, a continuous sinusoidal wave at a fixed central frequency. The signal is added by modulating the carrier so that it includes components of slightly higher and lower frequencies. The signal is encrypted as the degree of deviation of the signal from the central frequency. The signal is decrypted by converting the frequency deviations back into an audio signal. The issue is how much frequency deviation corresponds to a given change in the audio signal - the larger the deviation, the greater the fidelity of the audio signal, but the more frquency space the signal occupies. In order to have a successful system, the transmitting station and the receiver need to "agree" on this ratio, known as the modulation index.)

There are two standard formats for FM transmission - narrow and wide band (I'll spare you the specific characteristics). (It's also possible to transmit narrow-band FM with what is known as half deviation, and a corresponding reduction in signal quality, enabling even closer channel spacing - 7.5 kHz or 6.25 kHz. FRS/GMRS, for example, operates with half deviation narrow-band FM.)

So you can't compare narrow-band FM transmissions (such as NOAA weather radio, and most police/fire/etc. communications) to wide-band stereo FM (broadcasters on 88-108 MHz).

It goes without saying that you could squeeze many more stations onto the FM spectrum (at least a factor of 10-20 more by changing the modulation index), but you'd have to give up sound quality.

|6.24.07 @ 5:31AM|#

To HamRadioOp:

I don't believe that's the reason. The FM radio band occupies less than one octave (factor of two in frequency) so all the harmonics of any FM band station lie outside the band (and they can be found if you have a broadband receiver).

The only possibility would be subharmonics, and possibly ghost images created by leaks in circuitry (i.e. adding or subtracting the mixer frequency), but those would not correspond to factors of two.

I'm not sure, but I believe it was simply historical accident that FM broadcast band stations in North America use odd decimals. In other countries they use even decimals without any problem.

(On another note, AM broadcast band stations in North America are spaced at 10 kHz intervals. In Europe they are spaced at 9 kHz intervals. On occasion it's possible (on the East Coast) to pick up European AM broadcasters during the night when ionospheric absorption is lower - the immediate tipoff is when they appear to be "between" the "standard" AM channels (i.e. a station not at 770 or 780 but at 775, or 577 instead of 570 or 580). This is fun to do if you have a very good AM receiver and nothing else to do at 2 AM - listen "between" the stations (particularly at the lower end of the band, where ground wave propagation is stronger) for weak signals. You can also pick up distant domestic broadcasts - I pick up from New York stations along the entire Eastern seaboard and as far west as Michigan with regularity.)

Johnny Danger|6.24.07 @ 1:23PM|#

I was busted last year by the FCC for operating an "illegal" pirate radio station. There were a number of articles printed about the demise of Depot Town Radio (go ahead and google it). It's a damn shame that the NAB and NPR (yep, those overstuffed prima-donnas too) are keeping communities from having a voice by their congressional lobbying and payoffs (who ever said payola was dead... it's just take a different form). The Local Community Radio Act of 2007 is a good start.