NARBA for FM ?

[kfbkfb]

Here in KC, most FM stations are at 100kW, many years ago I noticed some of the FM stations in Chicago are much lower power (several thousand W) which I understand is so that their frequencies can be reused in nearby radio markets.

Considering the poor financial state of radio broadcasting in general, maybe it's time to reevaluate FM frequency allocations and power levels.

Maybe some FM frequencies can be vacated in the big city radio markets and all the remaining ones can be raised to 100kW FM signals.

Nearby radio markets would also vacate some FM frequencies and raise the power level of the remaining FMs to 100kW.

Considering that the curvature of the Earth limits FM reception, I think is would be advantageous to set all FM broadcasts to 100kW (or maybe more, to help with poor reception in certain areas).

Perhaps FM frequency time sharing (based on the AM frequency time sharing due to the 1941 NARBA) could be used in certain cases.


Kirk Bayne

 

[davideduardo]

Here in KC, most FM stations are at 100kW, many years ago I noticed some of the FM stations in Chicago are much lower power (several thousand W) which I understand is so that their frequencies can be reused in nearby radio markets.

Remember FM "power" is a combination of the radiated power and height.

6000 watts on the Empire State Building are the flat terrain equivalent of 50 kw at 500 feet, the standard for a class B FM.

There are zones of the country where the maximum power is 100 kw at 2000 feet, and others where it is 50 kw at 500 feet (or the metric equivalent). The lower limit zones have higher population densities and thus there is a need for stations in more cities that are close to each other.

Considering the poor financial state of radio broadcasting in general, maybe it's time to reevaluate FM frequency allocations and power levels.

The stations that are troubled are the daytime AMs, ones in over-radioed small markets, limited coverage AMs and some suburban FMs or rimshots in large markets. The good FMs in all markets can be profitable.

Maybe some FM frequencies can be vacated in the big city radio markets and all the remaining ones can be raised to 100kW FM signals.

That is next to impossible as there are stations in other "nearby" cities on the same frequencies and they all protect each other.

Perhaps FM frequency time sharing (based on the AM frequency time sharing due to the 1941 NARBA) could be used in certain cases.

Shared frequencies were a big thing in the 20's. By the 30's, nearly all were gone with just a handful making it to the early 40's when NARBA went into effect*. NARBA had nothing to do with frequency sharing.

* One of the very last shared frequencies went away last week in Chicago... a shared former Class IV channel.

 

[ZantennaG1]

I will add that most Chicago stations broadcast from some select skyscrapers in downtown (usually John Hancock Center, AON Building, Willis Tower, and the Trump Tower), and as a result, must reduce their power. As David said, 6kw at the ESB (which is about 1,200 feet) is just like 50kw at 500 feet. Yes FM is limited to the curve of the Earth, but terrain can make a huge difference.

I think it might be worthwhile to review a few stations and see if they are eligible for an upgrade, usually because a nearby station shutdown, but also due to FCC oversight. But 95% of current FM assignments are correct the way they are.

If HD Radio would've caught on, the FM band wouldn't be nearly as congested, however it didn't, and vacating frequencies is a far reach. Because not very many houses have an "HD" radio, translators are required, and run rampant on the FM band. Of course, when you ask someone what they think qualifies as "HD radio", it's either SXM or streaming.

At this point, we are just hoping that "Maxxcasting" takes off, but FM is finicky to work with.

 

[Greg Strickland]

Kirk that is a smorgasbord of topics for discussion!
I love radio too.
Make the most of whatever you are doing, here today.

 

[kfbkfb]

I'm mainly thinking about having the highest possible power FM signals, for proper operation of FM stereo, a strong signal is needed.

Google tells me that the range for full power FM reception is 30-40 miles from the transmitter.

Clean out the FM band (switch off/move some FM stations), allow 100kW (or more) power no matter high the tower (limited only by FAA rules).

There would be less FM stations since there would at least double the reception range between transmitters using the same frequency, but most FM users would get a very strong signal.


Kirk Bayne

 

[TheBigA]

Clean out the FM band (switch off/move some FM stations), allow 100kW (or more) power no matter high the tower (limited only by FAA rules).

That's not what the FCC wants to do. They want MORE stations, not less. They believe every station is a voice, and they want to increase the number of voices. Of course, every radio station also pays an annual fee to the FCC. So they want more stations.

 

[davideduardo]

Google tells me that the range for full power FM reception is 30-40 miles from the transmitter.

I had a roughly 1 kw ERP FM with its antenna at around 13,000 feet AMSL and it could be heard nearly 100 miles away in another city.

On the other hand, we found that if we increased power, the incidence of multipath in the local metro area increased, so we were better off with the added height and lower power. We also used only vertical polarization.

It's all about terrain and height in addition to power.

 

[TheBigA]

Maybe some FM frequencies can be vacated in the big city radio markets and all the remaining ones can be raised to 100kW FM signals.

Who decides which ones are forced to "vacate" and on what basis? Then how do you compensate the owners of those stations for their loss? Give them taxpayer money? From who's budget?

A lot of laws would need to be repealed for any of that to happen, and the idiots in congress can't even agree on who won the last election. I doubt very much they are even interested in this subject.