• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

FM Translators with Crazy Height

G

Gregg.

In a discussion about translators in Albuquerque, some folks were saying that certain FM translators have incredible coverage areas. The FCC says translators can only be powered at 250 watts or less. But there apparently are no maximums for height above average terrain (HAAT). And we all know that it's not just power but HAAT that determines how strong an FM station is.

For instance, Cumulus has an Active Rock station in Albuquerque that is on an AM station, 1050 KTBL. It is also heard on a 250-watt FM translator, K233CG at 94.5 MHz. The HAAT is over 4,000 feet! That would make it more powerful than most Class A FM stations, that run 6,000 watts on a 330 foot tower. When you look at the coverage map on Radio-Locator.com for K233CG, all of Albuquerque can hear the station as well as neighboring communities too.

When the FCC began allowing AM stations to simulcast on 250 watt translators, I guess the commission didn't think about cities like Albuquerque that are ringed by very tall mountains!
 
I'll use an example of K224CJ 92.7 on South Mountain in Phoenix. It is the translator for KDKB-HD2 93.3 (or, per station marketing, KAZG 1440). It has an HAAT of roughly 1500 feet and a directional antenna that slightly favors the NW and NE, where the geezer communities are (Sun City and east Mesa, respectively). It doesn't always work.

I live in NE Mesa, at 1500 feet ASL, about 400 feet above downtown Phoenix. K224CJ comes in like gangbusters in my area, 25 miles away. But if I drive even two miles southwest, near Falcon Field airport, it disappears. Falcon Field's elevation is 1365 feet ASL. The 52 watt nighttime signal from KAZG in south central Scottsdale comes in better in that area. Same is true for much of the East Valley. I can't speak for the Sun Cities since I don't live in that area.

Such a setup may work at 4000 feet, but in a basin where the towers are on a 1500 foot mountain on the south side of Phoenix, not so much. As always, each location is different.
 
K233CJ 94.5, K243CK 96.5 and K259CR 99.7 on Pikes Peak in OR...Fox Sports, KUMA and KTEL translators. Rising to 4485 feet, I have heard these signals well into the Cascades...I think my farthest so far is the 94.5 at 179 miles from Merritt Lake, 20 mi NW of Leavenworth. KATS completely blocked, no sign of KHTQ either.
Just heard the 96.5 from just south of White Pass hiking yesterday. 160 miles or so, at 250 watts. I picked up 99.7 just below Thorp Mountain, near Kachess Lake, in August 2020. 176 miles.
 
KeithE4 said:
I live in NE Mesa, at 1500 feet ASL, about 400 feet above downtown Phoenix. K224CJ comes in like gangbusters in my area, 25 miles away. But if I drive even two miles southwest, near Falcon Field airport, it disappears. Falcon Field's elevation is 1365 feet ASL. The 52 watt nighttime signal from KAZG in south central Scottsdale comes in better in that area. Same is true for much of the East Valley. I can't speak for the Sun Cities since I don't live in that area.
Click to expand...
I live just north of North Mountain and 1440 doesn't come in very well at night, so I imagine anyone out in Sun City would be lucky to hear a lick of it. It might just be the mountain blocking some of the signal since I can actually hear the station better in Glendale than in my area.
 
This one performs better than youd think, its stats are a bit deiceving.... because its near the top of the tower thats on top of a hill

W233BS-FM Radio Station Coverage Map

radio-locator.com radio-locator.com

Theres K220AD which is licensed for 1,090 Watts but its signal is not as good as youd expect because its on a short short tower
 
Gregg. said:
When the FCC began allowing AM stations to simulcast on 250 watt translators, I guess the commission didn't think about cities like Albuquerque that are ringed by very tall mountains!
Click to expand...

KINY 800 has had FM translators for 20 or more years

KIAM 630 has had FM translators for 30 years, that included alternate program delivery method waivers'
 
Here in the Detroit, MI area nearly every 2nd adjacent channel has a translator in operation. Only one or two licensed LPFMs, but at least 15 translators. Despite the impressive height on some of them, their coverage is definitely not on par with a full-power FM. At least not in my area. The comparatively low power output makes them difficult to receive indoors, or with smaller portable receivers.

I wonder if any of these translators actually show up, or have any measurable impact in market ratings?
 
I think if every term in Longley Rice prediction was used, rather than the truncated F(50,50) and F(50,10) predictions for simplicity before computers were widely available, these situations would be apparent. In Michigan, there are quite a few translators that work out to the equivalent of about 2 kW ERP/100 meters ERP, but not much above. It would be more accurate to say that they are roughly equivalent to 3 kW/100 meters HAAT Class As, but nowhere near Class Bs. However, the model breaks down for stations in adjacent markets that have few 1000 foot towers in areas where they could be used. There are many TV and FM station towers in larger cities at 1000 feet or more, and many translators on them. The LOS of these adjacent market stations is affected, and the translators interfere in the outer limits of the supposedly protected contours. If you look at the Longley Rice Maps of the translators and adjacent market stations and compare them, you can see where this might occur. In Detroit, many of the translators are limited to 99 watts because of 10.6/10.8 MHz IF Beat consierations, because they are on second adjacent channels to local full power Class B signals. Thus they are less than the 250 watt ERP limit. But they still interfere with adjacent market stations due to the prediction model still used.

I still suspect that many translators may be operating at more than licensed facilities. The ones in Detroit are now receiving complaints from the cochannel second adjacent drop ins in Windsor and Essex County. These may be ordered to reduce power, change channels, or go off the air under the International Agreement between the US and Canada.

The whole truth is that the FM BC band has been jammed up like the AM BC Band has been for 60 plus years. Attrition has reduced some of this on the AM BC Band, but that is a sad state of affairs.
 
Last edited:
K8PLW said:
I wonder if any of these translators actually show up, or have any measurable impact in market ratings?
Click to expand...
Translators for commercial stations never show up by Nielsen rule. Since they can not originate programming per the FCC, the originating station is what Nielsen lists... the HD channel or an AM.
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom