Wednesday, April 11, 2018


Not that many years ago the lowly FM translator was little known and seldom heard. Today FM translators have become an essential part of radio broadcasting and now are heard by millions of people. FM translators have been sold for hundreds of thousands of dollars in the past few years.

It was no surprise when the FCC released quarterly broadcast station stats as of March 31, 2018, that there are more FM translators than any other radio service.  According to the FCC, at the end of March, 7,604 FM translators were on the air.

There are several reasons for the proliferation of FM translators:

• FM is where the action is on the broadcast radio platform. FM is a convenient, free and ubiquitous service that listeners are in the habit of using frequently. The audio quality is good, stations are generally easy to tune-in and the most popular programming is on FM.

• HD Radio turned out to be a boondoggle and it never caught on with consumers.  HD Radio was born in corporate boardrooms. The designers and enablers of HD chose the system because it preserved the status quo. Big radio station owners didn’t need to worry about upstarts getting new digital dial positions.

HD Radio suffers from the same mindset that created “New Coke.” There was never any serious market testing of the system and consumers have just said “no.”  Broadcasters have found one thing HD Radio channels are good for: feeding signals to FM translators.

• The FM dial was getting crowded even before HD stations we allowed on FM. The FCC added to the clutter when it decided to “save AM” by moving it to FM. FM translator frequencies were “given” to AM licensees. Immediately AM stations began branding them “FM.”

• Look for a great wind of karma coming from the late Major Edwin Armstrong, the visionary inventor who was the  champion of FM radio.  

Today Eddie must be looking down from a heavenly perch thinking
"I told you so."

(Be sure to scroll down to learner about the father of the FM translators.)


On the left is a chart showing the growth of FM translators since they were first tracked in the fall of 1990.

You can see how the number of translators goes up in 2017 and 2017, due to the “move FM to AM” plan.

The number of LPFM’s now on the air is also rising. LPFM operations have become sophisticated and sustainable. 

Some raise a lot of money. Look for more LPFM’s because better operators are making it work.

After a two decadeS of steady growth, the pace of adding new FM stations has gotten slower. 

The biggest reason FM can’t expand is the glut of translator frequencies devoted to AM and satellite religious broadcasters.

Noncommercial FM stations have had an amazing upward trend since NPR debuted on key stations. 

The pace of adding new stations has also slowed for the same reasons as above.

The AM slide reminds me of this public radio true story:   

At a conference a person from a station asked researcher David Giovanonni

What is the best time to schedule radio drama? 

Giovanonni replied: 1938.

The 1950s and 1960s were the golden days of hometown AM stations.


Keith Anderson
The FM translator business begin? Probably began in 1963 in the beautiful Black Hills of South Dakota.

Keith Anderson was making lots of bucks with cable TV microwave systems and VHF TV translators.  Anderson manufactured “boosters” for TV stations in the Rocky Mountain West.  This was around the time John Malone (who founded cable giant Tele-Communications Inc. – TCI) was hooking up his first cable subscribers in Casper, WY.

Around this time, Anderson was approached by religious FM broadcasters who were seeking a way to cover more territory.  They suggested he manufacture translators similar to VHF-TV translators for FM stations. Keep in mind FM broadcasting didn’t come into vogue until the 1970s.

Anderson’s units were low power devices initially 1-watt.  Soon, at the urging of FM broadcasters, Anderson began building 100-watt and 250-watt units. They worked pretty well and religious FM broadcasters bought quite a few of them.

One of the religious broadcast engineers who saw the potential of FM translators was Harold Enstrom, an engineer at Chicago's Moody Bible Institute. He was in charge of expanding Moody’s radio coverage.  He began tinkering and improving Anderson’s devices.

In 1975 Enstrom moved to Rapid City, SD (near Anderson’s workshop) and became part of Tepco Electronics. A broadcast equipment manufacturer, Robert Jones, approached Enstrom with an idea: Build and market solid-state FM translators that were more reliable and had better audio fidelity. A $385,000 Small Business Administration loan started the ball rolling.

Enstrom, in a 2004 Radio World interview by blogger and engineer Scott Fybush spoke about the beginning of Tepco’s translator business:

“I began sending mailers to every FM station in the country. The pitch was this: If you locate a translator in the center of a small community, you can be heard just as well as a 100-kilowatt station 50 miles awa
Orders poured in and the Tepco translators became tremendous success. I was getting so many inquiries (about translators), after a while I didn't have time to write.”

Enstrom moved to Florida and founded FM Technology Associates. He continued selling Tepco Translators until his death in 2007. Keith Anderson, who died in 2014, became a major player in the satellite TV industry. Tepco is still in business.


  1. Translators do not prevent the addition of new FM stations because translators are an unprotected class. If there is room to put a full power station on a channel that has a translator on it, the translator has to go away when the full power station is licensed.

    The real reason there isn't growth in the number of FM stations is simply that the band is full in most well populated areas. That, and filing windows create huge "MX" mutually-exclusive application chains that cannot easily be broken.

  2. Quite few of the column headings on the charts are incorrect (second column).