Our recently published ebook about best practices for FM translators is a big hit with readers. This is an excerpt.
Jeremy Preece is president of consulting firm Wavelength Technical Solutions. He launched it recently after a 23-year engineering career with Educational Media Foundation. He has worked with hundreds of translators.
“They’re a phenomenal tool and a low-cost way to get your signal and content into places that are otherwise unreachable,” he said. “I don’t believe organizations like Calvary Chapel, EMF and others would be as far-reaching as they are without translators.” At one point EMF was installing a couple of translators each week.

The FCC’s decision to grant FM translators to AM stations obviously brought significant expansion of the service. “And HD fill-in translators are fantastic,” referring to translators that pick up and rebroadcast an HD multicast channel of the primary station. “You can get up to 250 watts, maximizing the coverage and impact of a translator,” he said.
He noted that translators are generally affordable to operate.
“If you want to put new programming on or try out a format or serve a second or third language in the community, you don’t have to chance it on a full-power signal, you could put on a translator through an HD SPS channel.”
[Related: “FM Translators Remain a Popular Tool”]
Where would somebody get started? FCC windows to apply for new translators are rare — there hasn’t been one since 2003 except for the AM revitalization initiative — so this can be a waiting game.
“You have to do your homework ahead of time and wait for those filing windows to open up,” Preece said.
“You can make changes to existing translators, but windows for new ones open only every couple of blue moons and are extremely short in duration. Be prepared. If you do your homework ahead of time, it makes it a lot easier to file and hopefully avoid mutually exclusive issues and other issues that arise during those openings.”
“An experienced applications engineer is the best place to start.”
Basics
Preece said simplicity is one of the benefits of translators.
“A low-power transmitter with a built-in FM receiver to pick up a feed station over the air, some coax and a tower to hang your antenna — that’s about it. Many translators can fit in small outdoor cabinets and use very little electricity. They take up little tower space, so rent often is not a big issue; you can even install them on rooftops, on baseball stadium lighting structures and so forth.”
He said you can typically build a translator for $20,000 to $40,000, including tower work. If you go from covering 50,000 people to 100,000 or more, it can be a really good investment for a station.
“Modern FM broadcast receivers such as the Inovonics Aaron 650 are phenomenal, and you can have a translator that sounds as good as any full-power station on the dial, even when it’s fed over the air,” he said.
“But consider all options. If your licensed feed is from an HD SPS channel, don’t feed it directly with the over-the-air HD signal, instead use an alternate means such as internet or STL to keep it at broadcast quality. You don’t want 24k audio on your FM translator; people aren’t going to engage with that.”
You don’t need an expensive remote control for a translator, but in most applications the translator must shut down if its feed goes down.
“Check the rules; basically, if your main station is down, the translator should be off, and if your HDs are down, the translator must also be off. But as long as the translator will mute itself when it loses its licensed feed, that’s usually legal.”
A good practice is to install an HD receiver like an Inovonics Sofia in your translator rack to monitor the HD audio and RF signal.
“Have it set it up with GPO or SNMP to shut off the carrier if the feed signal is down or silent. Build in a grace period of a few minutes to prevent bouncing the translator’s output,” he said.
“And although a remote control is not required, it’s not a bad idea to have one, to make sure the system is on, that it’s running full-power, that it’s not overheating or running with high VSWR because it’s snowing. There are affordable eight-channel remote controls.”
Legal IDs can be done through FSK, which most modern transmitters will provide.
“Make it sound as good as you possibly can. Build it well and to good engineering standards. If you have a small transmitter, put it on a UPS to survive short power outages,” Preece said.
And think about your antenna. The cheapest antenna might seem like a good idea until the middle of winter when it ices up or breaks apart and takes you off the air.
“Then promote the translator. Put the frequency on the side of the station vehicles and on the website. Add it to your top of the hour ID. Don’t think, ‘Oh it’s just a translator.’ These things can really garner an audience!”
He has seen situations where listeners had no idea that they were listening to a small translator, especially when it was built well.
“Invest in good equipment and pay attention to audio quality. If you’re feeding the translator with a relatively raw signal, use an audio processor and make it sound competitive. It will pop off the dial as much as any other station.”
Manage expectations
Preece agrees that you need to be realistic about the signal reach.
[Related: “With Translators, Be Realistic About Your Expectations”]
“If you’re covering a small town in New Mexico or Nevada, a translator can cover the entire city just fine, though you may not get great building penetration. With 10 watts you can cover cars very well, but reaching into a concrete building is another issue.”
In places like Los Angeles, New York and Chicago, translators can be difficult to make work.
“I once worked with a translator on Mount Wilson, one of the best places to broadcast from in Southern California, but there was so much co-channel interference coming from Mexico and Palm Springs that you could only hear it in a little section of Pasadena,” he said.
“Those are the kind of things you have to think about: co-channel stations, adjacent-channel interference, neighboring stations’ power and whether they’re running HD Radio. If a distant co-channel station is running HD, sometimes a radio will lock to that HD carrier, causing a jarring and poor experience for your audience. Noise can be a problem when everyone else is 30 dB higher than your translator.”
“You have to think about these things if you’re in a congested market; but if you’re in Ely, Nev., it shouldn’t be a problem and your translator can cover the market nearly as well as any full-power station.”
Because there is no height limit, translators can really deliver when they’re located up high.
“I worked on a translator up on Farnsworth Peak in Salt Lake City. It is on a good open channel and it covers for miles and miles,” Preece said, “while here in Sacramento, there are translators that are just a couple hundred feet off the ground and only cover a portion of the community.”
Also consider which side of the tower the antenna is mounted on.
“Put the antenna on a standoff mount that will give as much view as possible to the audience. Being on the ‘cheap side’ of the tower is not going to do much good when you’ve got just a few watts to throw at potential listeners.”
If your listening area has a lot of commuters who are going to be driving through the signal’s coverage area, be realistic with your expectations.
“Your return is going to be small because people aren’t as likely to tune in for a few miles and then lose it. You have to think about your audience, who’s listening, and who you’re serving with the signal.”
In general, Preece said, smaller markets in particular can benefit from translators.
“Sometimes you can get a couple of translators and daisy-chain them. Listeners will have to change frequencies, but you can serve those areas pretty consistently.”
Plan reception
What are the requirements for getting the content to the translator?
“For noncommercial translators operating at 91.9 MHz and below, you have a range of options. You can use satellite, internet and STLs,” he said.
“For a standard non fill-in FM translator (setting AM cross-service translators aside and talking just about an FM to FM), the only method that’s technically legal is over-the-air, which has posed problems. If you’re putting a translator at the very edge of your main’s coverage or it’s shadowed, it can be challenging to get a reliable signal. Legally you can’t say, ‘Oh, I’m just going to feed it another way,’ as that goes against the spirit and the letter of the law. It’s something to think about if you have a station on one side of a hill and you want to put its translator on the other side.”
If the translator is licensed as a fill-in using an HD-SPS channel, you can use alternate feed methods, which is helpful.
“Many folks use internet, which you also can do for FM translators licensed to an AM. But note that a satellite feed is out of the question if your translator operates in the commercial band, 92.1 MHz and above.”
So explore your feed considerations before you get too far, especially if you’re planning a commercial application.
“I’ve seen translators built that could not be legally fed due to reception problems. So first, take a radio to the tower site you are considering for your translator and make sure you can hear the feed station. If you can’t hear it at all, or there’s another station on top of it, things can get complicated and expensive. Intermodulation products at busy sites can be a huge problem when trying to receive a distant FM station.”
Secondary service
Remember too that you are susceptible to being bumped, which can happen at the least opportune time.
“Consider other stations on the dial,” he said. “If you’re covering up someone else, they may have a case to shut you down right after you build.”
“I’ve seen cases where a station has a sizable audience outside of their initial coverage zone, and people really like their content. If you put a translator on top of it, those listeners get upset and may make enough noise to the point where you are forced off the air or have to turn down power or change channels.”
Also keep tabs on who’s filing FM applications in the market.
“Another station might be granted a move and put their new contour over top of you, then your translator gets kicked off. So consider these scenarios in advance. If something like that happened, could I change channels? Could I move?”
Common modifications
Many discussions about translators involve options for moving or improving them.
“You might be able to move a translator closer to your target audience; you might find a better site to cover your audience,” Preece said.
“You might be able to do some hops. Or you might go from an omnidirectional antenna to a directional, putting more power where you need it, and even run a few more watts if you’re protecting someone on the backside.” Using HD subchannels to feed fill-in translators was a big development in the industry.
“If the contour of the translator is completely within the contour of the feed station and there’s no other interference issues, you can run up to 250 watts ERP. Imagine taking a 10-watt translator to 250 watts; that’s a great modification that gives you a significantly more potent signal and can be relatively inexpensive to build out,” he said.
“Maybe you have a translator that’s on the other side of town or even co-located with your main. Do the study to see if you can increase power if it were licensed as a fill-in. If your translator is on the edge of your full-power’s contour, see if it can be made directional and point back at the main. Now you can run all that power inside the main’s contour.”
There are many creative ways to maximize the performance and reach of a translator in these cases. Also, consider using your competitors to your advantage.
“Let’s say another local station with a huge contour has HD set up, but they don’t have a format on their HD-3 or HD-4, and you’ve got a translator opportunity. See if you can lease that unused HD channel and put your format on there.”
“You can then license the translator to that station — you’re still the owner, but you’re feeding it with their HD signal. Now your translator can operate as a fill-in at higher power, you get the bonus of your format now being on an HD signal in the market, and your station’s smaller contour or lack of HD equipment is no longer a problem.”
Preece has seen creative ways of doing this very inexpensively. “You can even feed their HD SPS channel with your FM signal over-the-air, eliminating the cost of additional internet circuits or an STL. Sure, you may have to pay some rent for the use of their HD-SPS channel but it’s still a win for both parties because they’re making a few bucks, your translator now delivers a much better signal, and you didn’t have to buy all the HD gear.”
Don’t forget them
Jeremy Preece believes translators also provide radio managers a chance to be creative.
“Radio needs fresh content, so why not try different formats? Try different languages or unique music formats that nobody else is doing. HD-fed translators are phenomenal for this purpose. Don’t be afraid to use translators to test the market. You might find that you have a really great opportunity to reach an untapped audience.”
And while translators can operate for long periods without much attention, Preece hopes stations won’t fall into that trap.
“In driving around the country I’ve seen too many translators where it seemed like they built it and never looked at it again,” he said.
“You find the air filter completely full of dirt and an active transmitter fault; no one has touched it in years. Make sure to perform routine inspections and service on translators, and keep an ear on them. Maybe the receive antenna has been damaged and now the translator is picking up noise, or the transmitter had a failure and is operating at a quarter of its power.”
“These types of issues directly impact your audience. So listen often and keep up on routine maintenance to get the most of your FM translator.”