An Across-the-Board AM Power Increase to Overcome Electronic Interference?
A petition was recently filed at the FCC proposing to allow all AM stations to increase to 10 times their current power in order to overcome the effects of interference that has grown up in most urban areas from the operation of all sorts of electronic equipment, fluorescent lights and other devices that simply did not exist when AM power levels were first established. The petition was drafted by an engineer, who argues that, as the amount of background noise from all sorts of electronic devices has increased, so has the noise on the AM band. He believes that the only way to make the AM signal usable is to vastly increase power on all stations. As the stations would maintain their relative power levels towards each other, he claims that there would not be increased interference between AM stations - but that the increased power levels would overcome the background noise. However, because of AM skywave issues, the petition suggests that nighttime power levels remain at their current levels.
How realistic is this proposal? The petition recognizes that, in border areas, the power increase could not happen without international coordination and the amendment of existing treaties. But, given the proposed high power for AM stations and the cumulative effect that their signals can have on distant stations, this increase could seemingly affect international AM stations even if the US stations increasing power are far from the border. However, the use of AM stations has been decreasing in some countries - in Canada, a number of AM stations have already ceased operating, so maybe the international implications could be overcome given enough time.
The proposal does pose other problems. Already, many AM stations have difficult problems locating acceptable tower sites when their present sites are lost. The potential for increased RF radiation concerns from AM stations with much higher power levels may well make power increases for many urban stations impractical even if this proposal were to be adopted. And, if a station cannot increase power due to RF concerns, such a station may be subject to severely increased interference from stations that are able to increase power.
Any adoption might also have a negative impact on the FCC's consideration of the proposal to move all AM stations to an expanded FM band, taking advantage of TV channels 5 and 6, which have been vacated by full power TV operators in many parts of the country. That proposal is already before the FCC as a way of dealing with many of the same issues that the petitioner identifies (see our post here).
There has obviously been a decrease in the listening to AM in many markets - with many AM stations going dark or selling for smaller and smaller prices. Do AM operators think that this is a viable proposal, or are there other technical issues with the proposal? Are there other ways for AM stations to overcome the interference posed by modern electrical devices. Any thoughts on these questions from our readers?
A possible solution to increase the service area of AM stations without increasing the ERP of the AM stations and thereby opening up a new can of worms concerning potential interference to other stations, is to allow FM translators to rebroadcast an AM signal in a larger area than what is allowed today. Currently FCC rules allow FM translators to serve as fill-ins for AM primaries if the 60dBu F(50,50) of the translator is entirely within the 2mV/m of the AM primary and also be contained within the area of a circle with a radius of 25 miles from the AM transmit site. Increasing the ERP of an AM by a factor of 10 is roughly equivalent to the .6mV/m contour. My suggestion is to allow FM translators to rebroadcast an AM primary as long as the 60dBu F(50,50) of the FM translator is entirely within the .6mV/m of the AM station and within 50 miles of the transmit site of the AM station. In conjunction with these new rules the FCC could allow major modifications of translator construction permits on a first come, first served basis for the sole purpose of relocating FM translators to rebroadcast an AM station. The AM stations could immediately enjoy the benefits of increased coverage and the FCC would enjoy the benefits of a reduced work load by processing a one step move for translators as opposed to the current policy of processing multiple step minor modifications.
We own and operate a "ma and pa" AM radio station. We have searched and tried to buy an FM translator in our area but with no luck, as the ones available haven't been officially approved due to the window closing. We looked at moving one from another area, but that proved too costly. Our point is this, we need to broadcast on an FM band not only to continue to stay relevant, but to cut down on the issue of interference your article has referred to. We would rather broadcast on FM than stay on an AM band. We cater exclusively to our local community with local HS sports broadcasts, local parades, events, etc. We lose most of our signal when the sun goes down and due to more and more interference. We have been waiting for years to have the opportunity to better serve our audience with an FM where they can hear our local game broadcasts at night. We support the FM translator option or reuse of channels 5 and 6. Many local operators are in the same boat as us, we want to survive, but it is getting tougher to serve our community with these issues we face.
As if it isn't hard enough to survive running a small AM station in this down economy, we also face competition from Satellite, HD and FM, it is becoming almost impossible to keep an AM station running. The time is now to allow the reuse of channels 5 and 6 or open the filing for FM translators or very soon AM will be a thing of the past. Gone will be the voice of the local community in which it serves.