Two radio stations on the same frequency close together

[CNGL-Leudimin]

Browsing several radio station lists I noticed two low-powered radio stations in the Philadelphia area, WQEW-LP and WJYN-LP, which broadcast on exactly the same frequency (98.5 FM) and have their transmitters pretty close to each other near Temple University. According to Radio Locator their signals cover almost exactly the same area. This makes me wonder several things. How the FCC allows two radio stations so close together to broadcast on the same frequency? Unless they are part time (one broadcasts while the other is off-air), or their antennas are highly beamed (since WJYN-LP is licensed for North Philadelphia and WQEW-LP targets mainly Chinese, and Chinatown is near downtown; it would make sense for them to be beamed North and South respectively) or are not at the claimed locations. I wonder how this works.

Any other locations where something like this happens?

[bandit957]

I do remember a few instances where the FCC allowed two noncommercial stations to broadcast part-time on a split schedule, but I didn't know they still did this.

I also remember a lot of instances of big commercial stations being in markets near each other and battling it out where the signals overlapped. For example, I remember a 92.9 in both Dayton and Lexington, and they'd battle it out in Cincinnati. Another example is WXLK and WKRR (or whatever they are now) in Virginia and North Carolina. Those stations were very close to each other for having such a high wattage. I remember in the mid-'80s when you'd travel south from Cincinnati listening to 101.9, it would get overtaken by another 101.9 around Lexington. I have no idea what this was, because I can't find any mention of a 101.9 in that area in that timeframe. There was a 101.7 in Richmond, but I don't know if it was ever 101.9.

[Life in Paradise]

I don't know if it has changed, but there were specific distances that transmitters had to be away from each other based upon the frequency.  Different FM frequencies would have different maximum wattages.  In my area frequencies such as 96.7 and 103.1 were only allowed about 3000 watts (that may have changed slightly since the 80s), but the physical transmitter/antenna had to be at least 50 miles from each other.  In my area, we did have a few stations that were right at that distance, and starting about 22-23 miles away from the transmitter, you would start to notice switching.  10k, 25k, 50k, 100+k had different distances for some of their frequencies.  The new FM stations transmitting daytime AM signals only have about 250 watts maximum.  I don't see where they have a distance that they have to keep, except that they need to be within the 25 mile radius of their AM station.

[CoreySamson]

It would be cool if there was a website that had a map that showed where all the stations of a particular frequency were in the country, honestly. If it had their ranges too, then that would be awesome, especially on road trips.

[bandit957]

I don't know if it has changed, but there were specific distances that transmitters had to be away from each other based upon the frequency.  Different FM frequencies would have different maximum wattages.  In my area frequencies such as 96.7 and 103.1 were only allowed about 3000 watts (that may have changed slightly since the 80s), but the physical transmitter/antenna had to be at least 50 miles from each other.  In my area, we did have a few stations that were right at that distance, and starting about 22-23 miles away from the transmitter, you would start to notice switching.  10k, 25k, 50k, 100+k had different distances for some of their frequencies.  The new FM stations transmitting daytime AM signals only have about 250 watts maximum.  I don't see where they have a distance that they have to keep, except that they need to be within the 25 mile radius of their AM station.

I remember 100.1 being considered a "frequency of doom" because it had a lot of small stations that switched formats all the time.

[CNGL-Leudimin]

I know of a worldwide map, the one at FMScan. I chose 98.5 because that frequency is special to me (I can receive two separate distant stations at home without interference, and one of them is semi-local to one of my favorite towns), and I noticed those two stations in Philadelphia, so I asked. The most likely explanation is that they are part-time stations, using a split schedule.

[ftballfan]

I'm not old enough to remember this, but in the 1980s, there were five stations on 100.1, all within 120 miles of each other:
WEMI Neenah-Menasha, WI (now WNCY on 100.3; unrelated to the current WEMI on 91.5)
WGLB Port Washington, WI (now WSJP, still on 100.1)
WRQT Bear Lake, MI (now WOUF, still on 100.1)
WSBW Sturgeon Bay, WI (now WDKF on 99.7; unrelated to the current WSBW on 105.1)
WSHN Fremont, MI (now WVIB and in Holton, but still on 100.1)

Here's a current example of two stations on 97.7 less than 70 miles apart:
WMLQ Manistee, MI
WQDC Sturgeon Bay, WI
There used to be a 97.7 in Sheboygan, 75-80 miles from both Manistee and Sheboygan (WWJR, now on 93.7 as WBFM) and another 97.7 in Kalkaska, about 70 miles from Manistee (WKLT, now on 97.5)

[bandit957]

There were literally 2 stations on 97.7 in the Cincinnati market. One of them was allocated because the major Cincinnati stations didn't want the first one competing with them.

[jp the roadgeek]

There are 3 105.5 FM's within a 50 mile radius of me, but I seem to be caught in a no man's land between all 3.  There is a WDBY licensed to Patterson, NY that serves the Danbury, CT area; WOGL in New London; and WWEI in Springfield, MA, a simulcast of WEEI.  There also used to be a couple of 97.5's, but one was a repeater that has since gone silent (the other is WALK from Long Island). 

You will see a lot of close together stations on the same frequency below 90 on the dial, as many are low power educational or public radio stations.  There are two 89.9's within 25 miles of me, but one is a 10 watt station with an effective radius of about 2-3 miles (and once featured yours truly on its airwaves).

[GCrites]

Right now there are two 92.9s in the Columbus metro. One is broadcasting from Downtown Columbus at 100 watts (CD92.9FM, the former CD102.5) whereas another (My 92.9) is in Delaware Ohio at 500 watts. Come January 1, though, both will be CD92.9.

[Hot Rod Hootenanny]

Right now there are two 92.9s in the Columbus metro. One is broadcasting from Downtown Columbus at 100 watts (CD92.9FM, the former CD102.5) whereas another (My 92.9) is in Delaware Ohio at 500 watts. Come January 1, though, both will be CD92.9.

According to WWCD 92.9 (formerly 102.5 and 101.1 before that) facebook page, WDLR will be switching from 92.9 to 96.7 on January 1st.

[dvferyance]

97.5 WZOK in Rockford and there is some other station in Chicago on 97.5. The 2 overlap Don't know why this was ever allowed. There are stations on 106.5 in Whitewater Milwaukee and Sheboygan again they all overlap. Stations on 91,7 in Madison Whitewater and Milwaukee.

[bandit957]

I think there is or was a 105.7 in both Baltimore and in York, Pa. I don't know how that was allowed, as those cities are very close to each other.

[Life in Paradise]

I think there is or was a 105.7 in both Baltimore and in York, Pa. I don't know how that was allowed, as those cities are very close to each other.

I believe that 105.7 is one of those old 3000 watt frequencies where transmitters had to be only 50 miles away.  The transmitter for York could be there or on the north side of that town, whereas the Baltimore station could have actually been licensed to a town like Glen Burnie, which is on the south side of the metro.

[bwana39]

Low power translators are even closer. Sometimes 20 -30 miles tops.  A translator is a station that re-broadcasts a primary station's signal to an outlying area on a different frequency. Of late it has been used to actually be the primary outlet. Examples are translators that re-broadcast the signal of an AM. While the AM  is TECHNICALLY the primary, the translator is the primary focus of the marketing both on-air and off. It is also a way to provide an analog outlet to programming on full power FM stations HD signals.  There are lots of other uses of translators, but they are becoming more and more abundant.

Generally they are under .25 kw output but newer technology makes them viable over a wider range than previously.  A class A (6KW) is limited to about 71 miles from transmitter to transmitter.  So that is just over 35 miles for each of them. While they are protected on a less than 20 mile radius, modern technology / engineering makes 6000 watts go a whole lot farther than it did a couple of decades ago.

[bandit957]

I wish we still had something like the M Street Radio Directories of the '90s to help us sort it all out.

[KEVIN_224]

There are 3 105.5 FM's within a 50 mile radius of me, but I seem to be caught in a no man's land between all 3.  There is a WDBY licensed to Patterson, NY that serves the Danbury, CT area; WOGL in New London; and WWEI in Springfield, MA, a simulcast of WEEI.  There also used to be a couple of 97.5's, but one was a repeater that has since gone silent (the other is WALK from Long Island). 

WFCS-FM 107.7 of New Britain serves Central Connecticut State University (CCSU) with its "massive" 36 watt signal. To the southeast is 107.7 of Pawcatuck, CT (village in Stonington) serving greater New London and Mohegan Sun as "Jam'n 107.7". Then there's also a 107.7 FM broadcaster in Enfield, CT to the north. I think it's from Asnuntuck Community College.

WYBC-FM 94.3 of New Haven is limited with their signal since there's already another 94.3 station on Long Island. 22 miles away from the WYBC transmitter is WERB-FM 94.5 of Berlin High School.

Lastly, we have WUCS-FM 97.9 of Windsor Locks/Hartford. It used to be in the Springfield, MA market as their country station. The City Place transmitter is directional due to WCTY-FM 97.7 of Norwich, to the southeast on CT Route 2.

[Dirt Roads]

Not close together, but ever since Saturday we've been getting CFTR (AM 680) in Toronto coming in alongside WPTF (AM 680) in Raleigh after sundown.  Neither is coming in great, but it's the first time I've ever been able to listen to two stations at once and understand both.  Getting local traffic reports at the same time as Toronto weather (in Celsius) was quite amusing.

[Concrete Bob]

This is my "go-to" website for all things radio-related (markets, frequencies, formats, call letters, signal strength, etc.):

http://www.radiostationworld.com/

[GenExpwy]

A long-time-ago example on the AM band was the Westinghouse stations in Massachusetts. From the 1920s to the early '60s, WBZ in Boston and WBZA in Springfield* had synchronized 50,000-watt** signals on 1030 kHz***.
* Originally, the call letters were the other way around.
**Beginning 1933.
*** Post- North American Regional Broadcasting Agreement.

Another pair of synchronized 50,000-watt stations was WBBM Chicago and KFAB Lincoln NE**** on 780 kHz at night.
**** Moved to Omaha and 1110 kHz in 1948.

[KEVIN_224]

I remember hearing WILD-AM 1090 of Boston being interfered with by WBAL-AM 1090 of Baltimore...near sunset and IN Boston. Specifically Downtown Crossing.

[ftballfan]

Some examples in Michigan, on the former FM graveyards:
93.5 FM (former)
WCLX Boyne City (now WBCM, still on 93.5 but upgraded to Class C2)
WATZ Alpena (now on 99.3, still WATZ)
WRCI Midland (now WKQZ on 93.3)
Ironically, WBCM and WATZ are now sister stations and both had country formats until earlier this year, when WBCM flipped to classic rock.

100.1 FM (current)
WVIB Holton
WBCH Hastings
These two are only 65 miles apart! A fairly recent one as WVIB used to be slightly farther from WBCH as WSHN in Fremont.

[Road Hog]

The FCC requires at least 0.4 MHz of space between radio stations in markets to prevent overbleed. There are only two frequencies open in DFW proper for full-power stations: 99.9 and 104.1. The latter was previously occupied but abandoned when Cumulus bought out Citadel and then did an LMA of the local ESPN affiliate, which counts against the number. FCC rules limit companies to 7 stations per market and 5 per band. I can't speak for 99.9 but it is extremely popular for Christmas light shows and other Part 15 endeavors.

(The ESPN LMA recently was not renewed, which potentially opens the door for another Cumulus acquisition in the Dub.)

[roadman65]

In Florida, you have WDBO and Eagle FM both in markets less than 100 miles apart.  Then Gainesville to the north uses the same frequency for one of their market stations.

You used to have WMGQ in Orlando (Magic 107.7) that was heard in Tampa Bay up until the FCC let a Spanish station use their frequency rather recently, so now you have Magic in Orlando and another in the nearby Bay Area using 107.7 MegaHertz.

[JMoses24]

There were literally 2 stations on 97.7 in the Cincinnati market. One of them was allocated because the major Cincinnati stations didn't want the first one competing with them.

I don't remember a second 97.7 in Cincinnati. Doesn't mean it didn't happen, but I only remember one 97.7 on the radio dial (WOXY-FM/Mason), and it was simulcast by a station on 99.5, WAOL-FM/Ripley, Ohio.

There were, however, two "Eagle"  branded stations for a very short time, before 99.3 (WSCH-FM/Aurora, Indiana) forced 96.5 (currently WFTK-FM) to adopt a different branding. For a time, three separate entities shared 95.7 (WVQC-LP/Cincinnati) which broadcasts from an antenna in Walnut Hills. I am not sure, however, if that arrangement is still in effect.

For purposes of this thread, two stations on 98.5 exist in the Columbus area: WINF-LP/Delaware and WSAX-LP/Columbus. There may, at one point, have also been a severe short spacing scenario in the Dayton area on 101.5 with WCLI/Enon, but WCWT-FM/Centerville is now at 107.3 and I'm not sure where to look to ascertain that.