Are fill-in translators allowed to use up to a maximum of 300 meters? If so, what limitations would prohibit them from increasing height up to that point, other than the obvious of causing interference to an existing station? Wouldn't any increase in height for such a translator require an FCC application (and approval) before anything of that nature could take place?
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Maximum HAAT for fill-in translator
- Thread starter passtheword
- Start date
Any translator, whether fill-in or not, can use any height above average terrain. However, just like their bigger cousins, they must reduce power as the antenna goes up. The rules are at Section 74.1235.
Of course, at extreme heights, the translator is still required to protect existing stations, which may reduce ERP to around a watt, or mandate the use of a directional antenna to provide additional protection.
Furthermore, the law of diminishing returns sets in. While we've successfully used a one watt translator for years, the small county seat we serve is, at most, a mile and a half across. For building penetration in more urbanized areas, more field is necessary. A good compromise is the 200~250 foot level, which often works out to about 100 watts here in the east.
Of course, at extreme heights, the translator is still required to protect existing stations, which may reduce ERP to around a watt, or mandate the use of a directional antenna to provide additional protection.
Furthermore, the law of diminishing returns sets in. While we've successfully used a one watt translator for years, the small county seat we serve is, at most, a mile and a half across. For building penetration in more urbanized areas, more field is necessary. A good compromise is the 200~250 foot level, which often works out to about 100 watts here in the east.
I do believe for clarification-sake though that FILL IN translators are allowed more height in many cases as long as they don't exend the contour of the orignating station. They are however bound by the 250 watt max. Am I right on this? There's a couple of them in STL I believe that are this way...
Perhaps a more direct way of asking the question would be: At what point does a translator need to reduce its ERP for reasons other than to protect another station or keep its contour from exceeding that of the parent station's?
I think we can make the assumption that you can always trade height for ERP (going up in height) regardless of class, so what we mean is how high can one go before the 250 watts (max) needs to be lowered because you exceeded height for your class?
Wes
I think we can make the assumption that you can always trade height for ERP (going up in height) regardless of class, so what we mean is how high can one go before the 250 watts (max) needs to be lowered because you exceeded height for your class?
Wes
For a fill-in translator, there is no HAAT limit, per 74.1235(a).
http://louise.hallikainen.org/FCC/FccRules/2011/74/1235/
For non-fill-in translators, power derating kicks in at 32 meters HAAT east of the Mississippi, 107 meters west of the Mississippi.
http://louise.hallikainen.org/FCC/FccRules/2011/74/1235/
For non-fill-in translators, power derating kicks in at 32 meters HAAT east of the Mississippi, 107 meters west of the Mississippi.
Thanks for all the info. If a station wanted to increase their HAAT, wouldn't that have to still be approved by the FCC before it could be done?
It would...but it's a pretty simple minor change, assuming the proposed new facilities meet the rest of the rules in part 74 (60 dBu of the translator can't extend beyond the parent station's 60, if it's an FM, or 2 mV/m and 25 mile radius, if it's an AM; can't interfere with any other existing facility, etc.)
If the translator is non-comm,not owned by the licensee , is just one 30 sec underwriting announcement per hour allowed on the translator? Seems like i read that somewhere. Also can the status on a non-comm 88.5 translator be changed to commercial or would it have to be in the commercial band to do that.
It has to be above 92 to be commercial, period. Be careful though because there are many that will pay much more for that translator to directly feed it with church music on 88.5. Translators in the reserved band are like gold!
As a translator owner and someone that works occassionally in the translator field, I think that there are several murkey areas of translator operation that tend to confuse people because the rules vary by situation.
First, if a translator is a fill-in. the AM or FM primary station does not have to own the translator, but they can. They can also lease time or work out any other deal that's mutually acceptable. The major caveat is that whatever translator they use, the translator's 60dBu contour cannot exceed the daytime service contour of the primary station (1mV for FM or 2mV for AM). There is also a maximum permitted distance for AM fill-ins.
FM stations can be rebroadcast on either fill-in or non-fill-in translators whereas AM stations can only be broadcast on Fill-in translators. The rules permit fill-in translators to be:
A. Operated with larger coverage areas (greater antenna height and up to 250W) than non-fill-ins. I have seen applications for translators with 250W at 300 meters giving them coverages that rival class A FM stations. There is no height limitation for fill-in translators, but there is a coverage limitation if the translator is used as a fill-in for an AM station. That limitation is that the translator's service contour cannot exceed 40km from the AM tower, even if it is still within the 2mV contour of the AM station. That effectively limits the height of AM fill-ins to between 300 and 600 meters in most cases.
B. Reimbursed/leased by AM or FM stations.
C. Can be, but not required to be, owned by the host station
D. Be fed by other methods besides just off-air signals. In other words, you can use an STL or two Dixie cups and a string to get programming to a fill-in translator.
The current FCC rules specify that AM stations can only be rebroadcast on translators authorized prior to May of 2009. Translators authorized prior to May of 2009 can be bought, sold, leased, bartered, etc. by AM stations and these translators can rebroadcast AM or FM signals. Translators authorized after May of 2009 can currently only rebroadcast FM (including HD) signals, but that will probably change after the next LPFM window opens.
Finally, it is worth noting that translator HAAT calculations are very different than for standard FM stations. For translators, the HAAT is calculated on a per-radial basis. Operating power is specified along each radial. not as the average of all radials. In other words, if you are a non-fill-in translator, using an omnidirectional antenna, the HAAT of the LOWEST radial determines the operating power for the entire translator.
Regardless of other limitations, or not, translator coverages are limted by the need to cause no interference. In most cases, translators cannot operate with anything approaching maximized facilities due to interference constraints, so omnidirectional translators with 250W at 300+ meters are pretty rare.
First, if a translator is a fill-in. the AM or FM primary station does not have to own the translator, but they can. They can also lease time or work out any other deal that's mutually acceptable. The major caveat is that whatever translator they use, the translator's 60dBu contour cannot exceed the daytime service contour of the primary station (1mV for FM or 2mV for AM). There is also a maximum permitted distance for AM fill-ins.
FM stations can be rebroadcast on either fill-in or non-fill-in translators whereas AM stations can only be broadcast on Fill-in translators. The rules permit fill-in translators to be:
A. Operated with larger coverage areas (greater antenna height and up to 250W) than non-fill-ins. I have seen applications for translators with 250W at 300 meters giving them coverages that rival class A FM stations. There is no height limitation for fill-in translators, but there is a coverage limitation if the translator is used as a fill-in for an AM station. That limitation is that the translator's service contour cannot exceed 40km from the AM tower, even if it is still within the 2mV contour of the AM station. That effectively limits the height of AM fill-ins to between 300 and 600 meters in most cases.
B. Reimbursed/leased by AM or FM stations.
C. Can be, but not required to be, owned by the host station
D. Be fed by other methods besides just off-air signals. In other words, you can use an STL or two Dixie cups and a string to get programming to a fill-in translator.
The current FCC rules specify that AM stations can only be rebroadcast on translators authorized prior to May of 2009. Translators authorized prior to May of 2009 can be bought, sold, leased, bartered, etc. by AM stations and these translators can rebroadcast AM or FM signals. Translators authorized after May of 2009 can currently only rebroadcast FM (including HD) signals, but that will probably change after the next LPFM window opens.
Finally, it is worth noting that translator HAAT calculations are very different than for standard FM stations. For translators, the HAAT is calculated on a per-radial basis. Operating power is specified along each radial. not as the average of all radials. In other words, if you are a non-fill-in translator, using an omnidirectional antenna, the HAAT of the LOWEST radial determines the operating power for the entire translator.
Regardless of other limitations, or not, translator coverages are limted by the need to cause no interference. In most cases, translators cannot operate with anything approaching maximized facilities due to interference constraints, so omnidirectional translators with 250W at 300+ meters are pretty rare.
"...or two Dixie cups and a string to get programming to a fill-in translator" Well, I guess that means they could use a Barix over the public internet system then eh? LOL! (ducking and running) All joking aside, it's sad to hear all the STL stuttering and farting on the air these days either from doing things on the cheap and using the internet, or occational issues with unlicensed or T-1 links due to HD radio needs. The reliability of our audio these days on the air isn't nearly as good as even a decade ago in lots of cases.
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