Summary of US Translators
The total number of translators licensed in the US is 5,814, with 401 active construction permits. Some of the 2,173 licensed LPTV stations are actually operating as translators, increasing this total significantly. This information is accurate as of May 2001.
There are 10 states that have over 300 translators and only one is East of the Mississippi River. There are many places where people receive their TV service via cable that gets its signal at the end of two and three translator hops.
The National Translator Association has commissioned a study on the number of households that do not receive direct free over the air signals from ABC, CBS, Fox, PBS, The WB and UPN networks. This information should be available later this summer and will be posted either here or on their website.
The following story is reprinted here by permission of Broadcast Engineering magazine where it appeared in their May 2001 issue in the Beyond the Headlines section. It is an enhanced version with additional information.
Multiple-Hop DTV Translators Work in Utah
By Larry Bloomfield
Probably the most important link in the chain from studio to viewer is the transmitter. Without it a broadcast station is nothing! In many parts of the country, the transmitter is not the last link before home reception, but an unheralded device, the translator or translators, extends its reach. When you get to the Rockies and west, it becomes a way of life. Without television translators, a significant part of the American viewing audience would be without free over the air television. 10 states have 300 or more translators with Minnesota, one of the ten, being the only one east of the Mississippi. According to Dave Hale, translator guru at Larcan-TTC in Lafayette, CO, approximately 70% of the nations translators are located in the Rockies and west. Even some cable companies depend on translators to serve their subscribers.
Jim DeChant, General Manager of KTVZ in Bend, OR echoes the situation that face many broadcasters: “I cannot cover my service area with our main (transmitter) only. We’d be hard pressed if we didn’t have the 8 translators.” Oregon has over 500 NTSC translators extending the range of the stations in Portland, Eugene, Medford, etc.
Although authorized under the same part of the FCC rules, don’t confuse Low Power Television (LPTV) with translators. America’s viewing audience is served by 2155 licensed LPTV stations, with another 1141 constructions permits on their way to becoming LPTV stations. This number doesn’t hold a candle to the 5805 licensed translators, with construction permits for 471 more in the works. Neither of these figures include the 3800 plus filings that were made during the open window filing period August of last year for both LPTV and translators.
Translators have been around for nearly as long as full power television. In this segment of the broadcast industry, things are very slow to change. One case in point is the translation of Channel 2, KBIC-TV Boise, ID to Channel 71 serving Burns, OR. It’s up and working as you read this and they don’t even make sets anymore that receive channel 71.
So, as we make the migration to digital television, this type of service becomes increasingly more important, including the legacy issues. Full power stations have been granted a second frequency to aid them in their transition to digital; but not so for translators. Dr. Byron St. Clair, President of the National Translator Association said: “We are extremely concerned about the present movement in the congress and the FCC to recover channels 52 – 59 before the transition to digital is complete. If these channels become unavailable for translator use, it will be virtually impossible to extend a significant number of DTV primary stations into rural areas traditionally served by translators.”
There have been, despite all this, tests and experiments to see how the currently accepted technology (8VSB) will perform in the rigorous geography of the west. Paul Burkholder, Communications director of Humboldt county, in the thriving metropolis of Winnemucca, Nevada started tests as far back as November 1999.
“We tested ATSC signals with low power transmitters and translators. for a period of 6 months,” Burkholder said. “I even wrote a 100 page book on it. 12 unique receive sites were used where we compared 100 watt NTSC signals with 10 to 60 watt digital 8VSB signals. During the initial test, we didn’t do any hops (translator-to-translator). We simply wanted to see if the digital signals could replicate NTSC coverage in the typical ‘west of the great planes terrain’; you know mountains and valleys.”
The tests did uncover issues that Burkholder says the translator companies are currently addressing. “Phase noise in standard heterodyne converters proved to be a big problem,” he said. Adding, “The type of converters most translator operators are familiar with, probably wouldn’t pass a digital signal.”
The tests didn’t stop with just translators and LPTV. “We did some work on microwave delivery to translators,” Burkholder continued. “We found that it wasn’t necessary to convert from 8VSB to one of the other modulation schemes such as QAM and the we could get several 8VSB signals into the 25 MHz wide microwave channel. We found that the standard IF frequency of 70 MHz, worked just fine, using off-the-shelf down converts, down converting to standard TV broadcast channels 3, 4 & 5. We’d inject those into the IF and let the microwave equipment do the up converting, recovering those channels at the other end of the microwave system. In stead of being able to carry only one NTSC channel on the microwave system, we found that we could carry up to 3 ATSC signals on the same carrier.”
“Although we did do some translator-to-translator testing, we turned that part of our testing over to Kent Parsons,” Burkholder concluded. Kent Parsons is well known to Utah broadcasters since he has been involved in the Utah state translator system for over 45 years. In addition to this he is the Vice-President of the National Translator Association. Since Utah has about 10 percent of the total translators licensed in the US, and with Parson’s experience, it was a natural match, not to mention that about 500,000 or 1/4 of viewers in Utah depend upon translators for TV service
“After four months of experimenting, monitoring and testing with two long-range repeaters, the conclusion reached is that DTV translators we worked with will, and do deliver quality television signals to rural viewers with high reliability and at reasonable costs,” Parsons proudly related. “The signals I'm receiving in my home after the double hop are the same quality as being transmitted from the originating television station in Salt Lake City.”
The tests were done with the cooperation of KSL-DT (Channel 38), an NBC affiliate owned by Bonneville International Corp.
The first leg in the translator double hop is located atop Levan Peak, some 83 miles from Salt Lake City. Parsons injected an interesting factor: “One of the anomalies is that this is not line of sight. In the path, not 5 miles from Farnsworth peak, where KSL-DT’s transmitter is located, there is a protrusion that sticks up about 180 feet above the line of sight. Other than that, the path is clear.
“At the first receive sight (Levan Peak), we are getting a signal strong enough that we have 29 db to spare without using a preamplifier. The received signal goes into a Zenith ATSC (8VSB "remodulator") cable translator which converts the signal to a standard 45 MHz IF frequency. We then up convert, using a General Instruments frequency agile up converter. This feeds, on frequency, a Larcan MX100 which produces 30 watts of digital television carrier power on channel 17 that feeds a PR450 directional Paraflector antenna made by the Scala Division of Kathrein Inc. Our experimental call sign for this location is K17FJ,” Parsons reported.
Parsons goal was to do get a digital signal into his home in Monroe, UT, where he could track error rates etc., but for that to happen it was necessary to translate the signal one more time, which they did at the Cove Mountain translator site, about 4 miles east of Monroe. “‘Cove’ has a direct, unobstructed shot from Levan Peak,” Parson’s said.
The second relay site, Cove Mountain is 67 miles from Levan Peak, the 1st site. “At ‘Cove’ we receive channel 17 from Levan Peak, again using a Zenith ATSC cable translator that has an output of 45 MHz. We opted to make our own up converter. We are using a crystal controlled oscillator/multiplier and a double balanced mixer which drives the one and six watt modules in a vintage 1980’s TTC XL20 translator. This gives us a digital out power of approximately one watt, which is feed into a cut to frequency (Channel 32) Paraflector. This is sufficient to cover our town (Monroe, UT),” Parson’s proudly reported. “Plans are to increase the power output of experimental station, K32FO, and its corresponding coverage, once permission has been obtained from the FCC.
“In one test, we found that, with very limited power, we can transmit very long distances. For example: we reduced the power and transmitted the signal 67 miles with only 10 milliwatts of power on channel 17 and got good pictures. Because of cliff effect, you either have a signal with digital or you don’t.” Parsons also pointed out that they are receiving channel 17 from a sight that also is transmitting a powerful channel 16 analog signal without any appreciable adjacent channel interference.
Parsons named other equipment used in these tests: “3 RCA DTC-100 set top receivers, which replicate what has been called second generation receiver technology and a Zenith test set that can be put into a ‘data mode’ so we can replicate up to third generation receiver technology. The point is, we are receiving good stable signals with the RCA’s at three monitor points. The experiments and testing we’re doing so far has to be the worst case scenario as technology can now produce third generation receivers which are much better than what we’re using. We are also using off-the-shelf existing inexpensive 4 bowtie Radio Shack antennas, and they works just fine!
Parson’s pointed out that they’ve been tinkering with this idea for sometime. He said: “With the winter Olympics coming and the looming loss of spectrum above channel 52, we’ve really been under the gun and couldn’t wait until the PBS went digital here in Utah, so we elected to use one of the existing DTV stations, KSL-DT.
Greg James, VP technology for Bonneville International Corp., which owns KSL-TV/DT in Salt Lake City said: “We’re pleased with what Kent has done in his DTV translator work. We would like to have done them on channel, but the FCC granted us test authority and it seems to be working very well. Want to see how far we can cascade these without having to re-clock them.” Parson’s said:, “The only errors we’ve been able to see are those which come from the network itself and none have been induced by our translator system.”
James continued: “We want to make our translator network all digital and feed the remaining NTSC translators off it until they have to go dark. That will give us both significantly better quality pictures and signals on our system. My hat’s off to Kent Parsons.”
St. Clare commented further: “The National Translator Association is very much encouraged by the success of the initial efforts at passing the digital signals through a chain of translators in Utah. This, and the success of a similar experiment in vicinity of Winnemucca – Humboldt county, NV are significant steps in retaining over the air television to rural America on into the digital era.”
Parsons concluded by saying: “The FCC has been very helpful and cooperative in granting the experimental authority. They are very interested in the results of our experiments and have asked for copies of our findings. It appears that the work we are doing will help establish the parameters for digital translators.”
Parsons refuses to take all the credit saying: “It was only made possible with the support of the University of Utah and Phil Titus, Director of engineering of KUED and KULC, (both PBS member stations) and with the help of Dennis Johnson and Ron Titcomb, translator field engineers with the university.” Parsons’ two sons, Mauri and Johnny also providing invaluable assistance in the leg work and testing by donated their time to make this all possible. “It was not an easy job. We did most of the work in the winter time on snow covered mountain tops at elevations over 9,000 ft. high,” Parsons recalled.
It was not difficult to hear the pride of accomplishment in Parson’s voice when he tells of the pristine pictures he gets in his Monroe, UT home. Those who have seen the results of this experiment are no longer skeptical that DTV can be implemented with translators. The bottom line in all this is that DTV translators work, can use modest power, will eventually cost about the same as analog translators, and produce quality service for those hundreds of thousands of rural TV viewers and the many cable systems who rely on translators.
To the National Translator Association