FM Translators

In our 9/6/07 issue we published a letter from Art Sutton, GA-Carolina Radiocasting, regarding FM translators for AM stations. His letter prompted a response from Kent Smith, WMJZ/WMJT, Gaylord, MI, which we published on 9/20/07 ... and a response to Kent from Art.

Here is the discussion:

When the NPRM [FCC Notice of Proposed Rule-Making] came out about AMs on FM translators, I made mention of the fact that the FCC should create a standard for the coverage of these translators not tied to the AM station’s 2 mV/m daytime contour. The reason is that exactly the same AM facilities will vary greatly in coverage across the U.S., due to differences in ground conductivity.

The example I used was this: a 1450 AM with 1KW in Cornelia GA gets a 2 mV/m daytime contour at nine miles from its tower, while the exact same facility at Yankton, SD enjoys a 2 mV/m contour at 34 miles from its tower.

So. an exact copy of an AM in the Midwest with one in the South will get nearly four times the coverage.

So, the translator on the AM in the South, or other regions of low AM ground conductivity, will be restricted greatly compared to the one in the Midwest.

I suggested a simple standard to be applied across the U.S.: An FM translator duplicating an AM station can’t have a 60 dBu contour extending beyond 25 miles of the AM transmitter site.

The maximum power allowed by the FCC for a FM translator is 250 Watts. So, how high up would the FM translator have to be to produce a 60 dBu of 25 miles? A thousand meters, or 3,280 feet..assuming the translator were to meet all signal-separation rules.

The tallest TV tower in the U.S. is just over 2,000 feet, so you can see that in reality, there will be no FM translators producing a 60 dBu of more than 25 miles—not even close. However, why limit them to just nine miles to equal the AM 2 mV/m contour when, in fact, technically, the contour might could go 12 miles if not limited by the AM 2 mV/m contour?

I’d even settle on a 20-mile limit for the translator 60 dBu.

—Art Sutton, GA-Carolina Radiocasting, Toccoa, GA, sutton@gacaradio.com

Regarding Art Sutton’s take on AM on FM translators (SMRN 9/6/07), I am sure he would like a 25- or 20-mile contour on a nighttime FM translator. But in my opinion, this whole proposal is a disaster.

We have the AM band, which has its limitations. Now we want to make up for these limitations by moving it to the FM band and putting an even greater burden on FM, which is already overloaded with signals?

We want to dilute the FM band and have two screwed-up bands. This on top of IBOC—and we don’t even know where we will end up IBOC yet.

Have you looked at your contour protections for your FM stations? In the big picture, your protected contours are not that big. Your current signal goes well beyond the contour protections. If a translator goes on the air on your frequency just outside of your protected contour, it will degrade your signal and you will have not protection from this. None. I have been there and dealt with this. You have no recourse.

I don’t get it. I think this is short-term thinking that will create even bigger problems down the road.

—Kent Smith, WMJZ/WMJT, Gaylord, MI, kent@radioeagle.com

Kent Smith responded in your September 20th issue to my proposal that the FCC restrict the use of FM translators by AM stations to a 20 or 25 miles primary signal contour instead of the AM’s 2 mV/m being the limit for the translator primary signal contour. The point I made was due to the difference in ground conductivity around our nation, the size of AM 2 mV/m contours vary greatly even with identical facilities.

Mr. Smith described my proposal as a "disaster" and said it would lead to further degradation of FM reception.

He is right to point out that most FM stations get a listenable signal beyond their protected contour, 60 dBu (1 mV/m) on all classes but B channels, which is 54 dBu (.5 mV/m). However, it should be pointed out that the technical rules for FM translators are not changing. All that is changing is that an AM station could put its programming on the translator.

Just because AMs can use FM translators isn’t going to change anything on the FM dial. If a translator can be located in area and protects all full-service FM stations, nothing can stop it unless you get the FCC rules changed.

The genie has long been out of the bottle on FM coverage. If we wanted to protect the usable signal beyond our FCC protected contour, we should have gotten the technical rules changed about 40 years ago. It should be pointed out that the FCC has maintained the same interference standards on FM for a long time. They have even eliminated rules which allowed AMs to interfere with each other (remember the days when if you were the only AM in a market, you could accept but not deliver interference?) but in many places the damage had been done.

One thing which might make Mr. Smith feel better is that most folks believe that only the presently-licensed translators and CPs are the ones which will populate the marketplace. There are thousands of mutually-exclusive translator applications which will never see the light of the radio dial because they simply don’t fit in the FM spectrum. The odds are very slim that we can apply for a new FM translator.

So, putting an AM on an FM translator has absolutely nothing to do with creating interference to full-power FM stations. What it does do is give many struggling AM stations an opportunity to serve their communities, at least. In reality, that’s likely the issue with people opposing this measure. They don’t want that struggling AM across town to suddenly have the ability to compete on the FM band.

That battle, too, was lost a long time ago. The FCC has long held, "The more, the merrier."

—Art Sutton, GA-Carolina Radiocasting, Toccoa, GA, sutton@gacaradio.com