the unique fm signals very odd indeed

[lawman]

I noticed on my trip to the Motor City last week most of all the FM signals are on office buildings or small towers scattered throughout the city, one interesting tower was WGPR with all those bays. Due to their low antenna height they all utilize tremendous power to make up for that. I think most large metros have all FM signals on either one or two tall skyscrapers or in an antenna farm with many using the same towers and bays. So why is Detroit different, are the Television signals scattered also, would of been hard years ago before cable to keep moving your TV antenna to beam in on one. That is why TV stations tried to keep all signals in one spot, not so with FM.

 

[davideduardo]

I noticed on my trip to the Motor City last week most of all the FM signals are on office buildings or small towers scattered throughout the city, one interesting tower was WGPR with all those bays. Due to their low antenna height they all utilize tremendous power to make up for that. I think most large metros have all FM signals on either one or two tall skyscrapers or in an antenna farm with many using the same towers and bays. So why is Detroit different, are the Television signals scattered also, would of been hard years ago before cable to keep moving your TV antenna to beam in on one. That is why TV stations tried to keep all signals in one spot, not so with FM.

Detroit is by no means unique. Philadelphia has stations spread around the market, although some are concentrated in one area.

Which brings up a point: when FM started growing in the late 60's, many stations that had spent as much as two decades side-mounted on their sister AM's tower looked for more height. They often leased space on TV towers in the market... and TV stations all liked to be in the same place because that way viewers needed only one antenna "beam"... so the FM tended to be concentrated.

Markets like Cleveland and Pittsburgh also developed this way... some near or at the TV sites, some elsewhere. In DC, many (those that could) located in NW, where the TVs were. But many, either being suburban licenses (Manassas, Morningside, etc) or unwilling to pay the costs, were located elsewhere.

Dallas has many of the big signals at the TV farm, south of the metro at Cedar Hill. But there are nearly a dozen that are scattered in an arc from far west to the north and northeast, all serving DFW.

Markets with hills will find the bigger stations atop the hills, but those with spacing issues on lower elevations or buildings. Phoenix is like that.

The limiting factor for some FMs that precludes going to antenna farms or a single building or two (Willis and Hancock in Chicago, for example) is spacing. By the time FMs wanted to upgrade, they may have been too late to move to the ideal spot due to the distance to other stations. So they located where they could get the best signal into the market. Atlanta has a lot of those cases, for example.

San Juan, PR, has FMs on at least 5 different mountain ridges or hilltops (La Santa, El Cubuy, Aguas Buenas, Corozal, El Yunque) depending on spacing issues and the original COL.

In LA, many of the full Class B station are along the crest of Mt Wilson, but there are others on Flint Peak, Signal Hill, Hollywood Hills (Mulholland) Sylmar, Baldwin Hills, Verdugo Mountain, and a half dozen other locations because they could not, technically, go to the top of Wilson.

 

[lawman]

Speaking of Philly, aren't mostly all the FM and TV signals in the Antenna Farm. A few years back only 93.3 and 106.1 were the only two signals not in the farm, 100.3 moved there years back. I don't know the technical end but 93.3 wanted to move there but something with 103.9 prevented it, why 106.1 never moved is a mystery. A few years ago two new move in's did not locate there, 97.5 moved with 106.1 and 107.9 with 93.3, don't know why they did not move to Roxborough?

 

[SomeRadioGuy]

Speaking of Philly, aren't mostly all the FM and TV signals in the Antenna Farm. A few years back only 93.3 and 106.1 were the only two signals not in the farm, 100.3 moved there years back. I don't know the technical end but 93.3 wanted to move there but something with 103.9 prevented it, why 106.1 never moved is a mystery. A few years ago two new move in's did not locate there, 97.5 moved with 106.1 and 107.9 with 93.3, don't know why they did not move to Roxborough?

103.9 is the 10.6 IF of 93.3

 

[Schroedingers Cat]

Rather than start this over, here is a thread which discusses many of the issues regarding collocation of FM towers in the Detroit Area. It's about the proposed/under construction Hudson Tower. From the Michigan Radio TV Buzzboard.

https://www.mibuzzboard.com/phpBB3/viewtopic.php?t=46175

 

[fybush]

Philadelphia is actually one of the more concentrated FM markets in the country. The vast majority of the class B FMs in the market (88.5, 90.1, 90.9, 92.5, 94.1, 95.7, 96.5, 98.1, 98.9, 100.3, 101.1, 102.1, 102.9, 103.9, 104.5, 105.3) are on one of the Roxborough towers. WMMR is, as noted above, on One Liberty because of the IF spacing issue to 103.9. 106.1 has historically always been up at the Wyndmoor tower site where the old WPTZ-TV started (and later WPCA/WPHL 17), and 97.5 ended up at Wyndmoor as well after moving in from Trenton.

Detroit is one of the most spread-out FM markets in the top 20, up there with San Diego and Tampa. Most of the others are either all centered on a single site or tower farm (NYC at Empire, LA at Mount Wilson, Phoenix at South Mountain, Dallas at Cedar Hill) or split fairly evenly among two or three major sites (Newton/Needham and the Prudential Tower in Boston, Hancock and Sears in Chicago, Beacon/Sutro/San Bruno in San Francisco). Market 20, Nassau/Suffolk, is an outlier because it has no one urban center and stations are licensed all over the place. And as Sr. Gleason will surely confirm, Puerto Rico is a unique outlier as well.

 

[davideduardo]

Philadelphia is actually one of the more concentrated FM markets in the country. The vast majority of the class B FMs in the market (88.5, 90.1, 90.9, 92.5, 94.1, 95.7, 96.5, 98.1, 98.9, 100.3, 101.1, 102.1, 102.9, 103.9, 104.5, 105.3) are on one of the Roxborough towers. WMMR is, as noted above, on One Liberty because of the IF spacing issue to 103.9. 106.1 has historically always been up at the Wyndmoor tower site where the old WPTZ-TV started (and later WPCA/WPHL 17), and 97.5 ended up at Wyndmoor as well after moving in from Trenton.

Detroit is one of the most spread-out FM markets in the top 20, up there with San Diego and Tampa. Most of the others are either all centered on a single site or tower farm (NYC at Empire, LA at Mount Wilson, Phoenix at South Mountain, Dallas at Cedar Hill) or split fairly evenly among two or three major sites (Newton/Needham and the Prudential Tower in Boston, Hancock and Sears in Chicago, Beacon/Sutro/San Bruno in San Francisco). Market 20, Nassau/Suffolk, is an outlier because it has no one urban center and stations are licensed all over the place. And as Sr. Gleason will surely confirm, Puerto Rico is a unique outlier as well.

When I referred to some of the markets, I was considering every station licensed as "home" to the MSA, per the Nielsen definition.

In the case of Philadelphia, that means stations like WRDV, WBYO, WEMA, WZZD, WLBS, WBMR, WYPA, WDBK and the likes. While most of the "heritage" stations long ago tried to get power and height, some didn't or couldn't or were rimshots.

Looking at LA, we have 33 not on Wilson, and 20 that are. Of course, those 20 are mostly the most listened to stations in the market (except for KPFK) but the 33 not up there include KLAX, KYSR, KROQ, KXOL, KRCD/KRCV, KBE/A/KEBN, KWIZ, KFSH, KDAY, KJLH and KLYY which together have nearly 30% of market listening.

The OP asked why not all stations were in the same place.

In this case of Los Angeles, many of the stations not up on Wilson are Class A, and some of them even protect the Wilson second adjacents. Others, like KLAX, KROQ, KXOL and KYSR, are hemmed in by cochannel and adjacent channel stations elsewhere (and would jump over tall buildings to get up to Wilson if they could). And a number of them could not move to Wilson and continue to put the required signal over the Community of License. I was told that one station that could move up would have ended up with about 30 watts, which would have been even worse than when Cox put 98.3 on a foothill peak, but had to run just 570 watts. It had a good signal nowhere.

Other examples of spread out sites can be seen in markets like McAllen/Brownsville, where the market, like Long Island, is a collection of communities with stations sprinkled up and down the LRGV. Worse: Traverse City, with stations across the Mitten from Beulah to Cheboygan.

One of the strangest major markets is San Francisco. While the major stations are at just a few sites, the market includes Santa Rosa and San Jose in the MSA, and each of these had numerous stations that are local to just the far north of the market or the South Bay area. This is a case where essentially none of the biggest FMs covers the whole market, from Santa Rosa to Campbell and over to Contra Costa East, so the ones that cover the most people generally win if the programming is good. The Arbitron/Nielsen market definition comes from the days when KSFO, KFRC, KCBS, KGO and KNBC/KNBR were the owners of most of the audience... and they did cover it all.

 

[fybush]

I guess it's all in how you look at "concentrated." I think of Traverse City as fairly concentrated because with one big exception, WTCM-FM, everything that's actually in Traverse City is all within a couple of miles up on the hill west of town. The other stations, to the extent they're ever even on the air, may be part of the metro but for the most part don't have much signal or audience in Traverse itself.

Any large metro is going to have signal sprawl if you look at everything that's "home" to that metro, pretty much by definition. "New York" sprawls from Ocean County north to Putnam; like LA or Chicago, it includes plenty of class As with multiple co-channel signals in various corners of suburbia.

Although even there, you can discern some patterns. A relatively flat metro like Chicago has the central city Bs on Hancock and Sears (and the outliers, 97.1 on Aon, 92.3 in Indiana and 106.7 in Des Plaines) and second-adjacent As scattered far and wide all around the city. Go out west to Salt Lake City, for instance, and most of the big Cs cluster up on Farnsworth Peak to the west - but their second-adjacent neighbors are also largely all concentrated at one spot, Humpy Peak 60 miles to the east, with boosters to reach the metro.

 

[davideduardo]

I guess it's all in how you look at "concentrated." I think of Traverse City as fairly concentrated because with one big exception, WTCM-FM, everything that's actually in Traverse City is all within a couple of miles up on the hill west of town. The other stations, to the extent they're ever even on the air, may be part of the metro but for the most part don't have much signal or audience in Traverse itself.

The case there is that of the MSA (Nielsen's, not the OMB's) population, only 30% is in Grand Traverse County. The next most populous county is Emmet, a far piece up the road and outside even WTCM's 60 dbu.

Interestingly, WTCM had a CP for nearly 2000 feet some time ago. I would imagine that the lead on the project was Ross B's TV station, WPBN ("Paul Bunyan Network") and they remained at about 1,300'.

Oh, and it was 60 years ago last summer that I first visited WTCM on Front Street. Beautiful all-RCA facility.

 

[Schroedingers Cat]

WTCM -FM 103.5 just wanted to preserve its Full Class C Status as long as possible. I don't think they really wanted to spend that much to go up near 2000 feet. Though if they could have moved to a really high site, they might have been able to. The 92.9 in Cadillac continues to eliminate a lot of territory due to the IF restriction. Other Class Cs also precluded a lot of territory.

WCXT 105.3 Hart sat on a Full Class C before downgrading to C1 and eventually to Class B. It precluded a lot of upgrades, and by the time the rules changed, it was too late like you both said.

Northern Michigan had a large regional economic change when I-75 was built. When I was really young, our family vacationed on the Sunrise Side.

When we went to Crystal Lake, WCCW 1310 and WTCM 1400 didn't come in well. I listened to WDBC 680 Escanaba and WDOR 910 Sturgeon Bay.