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Why Did Some LA Stations Never Get on Mount Wilson?

G

Gregg.

All but five major FM stations in Los Angeles are on Mount Wilson, at least 2,800 feet above average terrain. Los Angeles is supposed to be Class B territory, averaging 50,000 watts at 500 feet. That means all but four Los Angeles stations are WAY overpowered. (While not on Mount Wilson, KYSR, at 75,000 watts, is also overpowered.) Many Los Angeles stations got on Mount Wilson in the early days of FM radio before the FCC decided on these rules. But some of them relocated to Mount Wilson well after the limits were set, ignoring modern FCC regulations.

Why did the FCC allow them to go on a mountain nearly double the height of the Empire State Building coupled with power levels FAR beyond Class B? And why did KXOL, KLAX, KYSR and KROQ never relocate to Mt. Wilson if everyone else did?

=======
On Mount Wilson for decades...

90.7 KPFK
92.3 KRRL
93.1 KCBS-FM
94.7 KTWV
95.5 KLOS
101.1 KRTH
101.9 KSCA (But was only 640 watts until the 2000s. Now at 5,000 watts.)
102.7 KIIS-FM
103.5 KOST
104.3 KBIG
105.1 KKGO
107.5 KLVE

=======
Got to Mount Wilson in recent years despite FCC regulations...

89.3 KPCC (Was on a -520 foot tower, yes minus, in the 1970s. Now on Mt. Wilson but only at 600 watts)
91.5 KUSC (Was on a 140 foot tower in the 1970s, went up to 930 feet in the 1980s)
93.9 KLLI (Was on a 770 foot tower until the 1980s)
97.1 KNX-FM (Was on a 770 foot tower until the 1980s)
99.5 KKLA-FM (Was on a 240 foot tower until the 1990s)
100.3 KKLQ (Was on a 1,130 foot tower until the 1970s)
105.9 KPWR (Was on a 770 foot tower until the 2000s)

=======
Never got on Mount Wilson...

89.9 KCRW
96.3 KXOL-FM
97.9 KLAX
98.7 KYSR
106.7 KROQ


.
 
Gregg. said:
All but five major FM stations in Los Angeles are on Mount Wilson, at least 2,800 feet above average terrain. Los Angeles is supposed to be Class B territory, averaging 50,000 watts at 500 feet. That means all but four Los Angeles stations are WAY overpowered. (While not on Mount Wilson, KYSR, at 75,000 watts, is also overpowered.) Many Los Angeles stations got on Mount Wilson in the early days of FM radio before the FCC decided on these rules. But some of them relocated to Mount Wilson well after the limits were set, ignoring modern FCC regulations.

Why did the FCC allow them to go on a mountain nearly double the height of the Empire State Building coupled with power levels FAR beyond Class B? And why did KXOL, KLAX, KYSR and KROQ never relocate to Mt. Wilson if everyone else did?

=======
On Mount Wilson for decades...

90.7 KPFK
92.3 KRRL
93.1 KCBS-FM
94.7 KTWV
95.5 KLOS
101.1 KRTH
101.9 KSCA (But was only 640 watts until the 2000s. Now at 5,000 watts.)
102.7 KIIS-FM
103.5 KOST
104.3 KBIG
105.1 KKGO
107.5 KLVE

=======
Got to Mount Wilson in recent years despite FCC regulations...

89.3 KPCC (Was on a -520 foot tower, yes minus, in the 1970s. Now on Mt. Wilson but only at 600 watts)
91.5 KUSC (Was on a 140 foot tower in the 1970s, went up to 930 feet in the 1980s)
93.9 KLLI (Was on a 770 foot tower until the 1980s)
97.1 KNX-FM (Was on a 770 foot tower until the 1980s)
99.5 KKLA-FM (Was on a 240 foot tower until the 1990s)
100.3 KKLQ (Was on a 1,130 foot tower until the 1970s)
105.9 KPWR (Was on a 770 foot tower until the 2000s)

=======
Never got on Mount Wilson...

89.9 KCRW
96.3 KXOL-FM
97.9 KLAX
98.7 KYSR
106.7 KROQ


.
Click to expand...

For what it is worth, KYSR is actually on Wilson sort of… one of the aux licenses is up there with 5 kW into a directional. That’s more than some other licensed mains like KSCA.
 
If we have a major quake 8 points or higher all the stations will be knocked off the Air. That's the only disadvantage to be on mt Wilson
 
30james said:
If we have a major quake 8 points or higher all the stations will be knocked off the Air. That's the only disadvantage to be on mt Wilson
Click to expand...
First, there is no fault in the area judged capable of an 8 or greater. Second, rock based locations are not subject to liquefaction so Mt Wilson sites are likely much better than the LA Basin areas.

Just look at the Long Beach quake in the 30's... considerable liquefaction of soft areas with no bedrock. On the other hand, see how the mountain areas of the SF Valley did in 1994 vs. the liquefaction zones of places like areas along the 10 Freeway, Sherman Oaks, North Hollywood and the like did then.
 
DavidEduardo said:
First, there is no fault in the area judged capable of an 8 or greater. Second, rock based locations are not subject to liquefaction so Mt Wilson sites are likely much better than the LA Basin areas.

Just look at the Long Beach quake in the 30's... considerable liquefaction of soft areas with no bedrock. On the other hand, see how the mountain areas of the SF Valley did in 1994 vs. the liquefaction zones of places like areas along the 10 Freeway, Sherman Oaks, North Hollywood and the like did then.
Click to expand...
Thanks David for your reply
 
Pretty much everyone on Wilson has aux sites at lower locations. It's not so much earthquake risk as fire (it's only been a couple of years since a huge wildfire came almost up the mountain to the transmitter sites) and snow making the sites inaccessible.

Audacy's sites are mostly backed up at the KROQ Verdugo location, iHeart's are at the KYSR Briarcrest site, with others at Flint Peak in Glendale mostly.

As for why some stations never made it up the hill, I don't know all the answers. I think a lot of it was the post-1964 spacing rules and Mexican treaties. So for instance, 101.9 could go up to Wilson based on pre-1964 grandfathering to 101.5 and 102.1 in San Diego, but it was limited in power because of the 101.7 to the east in Lake Arrowhead (is that right?)

I think 106.7 is especially problematic because although it and 106.5 in San Diego both existed pre-64, Pasadena was low enough in power that it was fully spaced back then, and so it has no grandfathering to fall back on. And then it got more first-adjacent spacing constraints up in the Victor Valley much later on, so it really can't do much about getting off Verdugo.

And while I haven't run all the numbers (and am doing this from memory on the road), I suspect KYSR's big limitation is 98.5 in Palm Springs.
 
PTBoardOp93 said:
As far as I understand, KPCC's facility is conforming to Class B limits, so the changes to "super power" rules would not affect that station.
Click to expand...
Yes, I would guess that 600 watts at 2,923 feet would put KPCC within Class B limits. When KSCA 101.9 was 640 watts at 2,830 feet, that one also conformed. But sometime in the last 20 years, KSCA's power got bumped up to 4,800 watts. That would be fine on the Sears Tower. Most Chicago FMs are around 4,000 to 6,000 watts. But 4,800 watts on Mount Wilson is now very overpowered.

KPWR 105.9 also got its overpower bump in the last 20 years. KPWR signed on in 1956. Most of its existence, 105.9 was 72,000 watts at 770 feet. Still overpowered but not as much as today. How did the FCC say in the 2000s, "OK KPWR. We will let you go on Mount Wilson at more than 3,000 feet. And you can do it at 25,000 watts. Class B regulations be damned!"
 
Gregg-

That is a big question. You stated a lot of things there in your post. Everything that happened there has a reason.

My view is the people at FCC have done an excellent job. The people at the radio stations acted in their best interests with the resources available every day. There have been a lot of days.

The radio stations and the FCC are human beings.
 
Gregg. said:
Yes, I would guess that 600 watts at 2,923 feet would put KPCC within Class B limits. When KSCA 101.9 was 640 watts at 2,830 feet, that one also conformed. But sometime in the last 20 years, KSCA's power got bumped up to 4,800 watts. That would be fine on the Sears Tower. Most Chicago FMs are around 4,000 to 6,000 watts. But 4,800 watts on Mount Wilson is now very overpowered.

KPWR 105.9 also got its overpower bump in the last 20 years. KPWR signed on in 1956. Most of its existence, 105.9 was 72,000 watts at 770 feet. Still overpowered but not as much as today. How did the FCC say in the 2000s, "OK KPWR. We will let you go on Mount Wilson at more than 3,000 feet. And you can do it at 25,000 watts. Class B regulations be damned!"
Click to expand...
Regarding the later Mt.Wilson move-up's, here's a quick summary. Doing this from memory, so feel free to correct if small details are wrong:
89.3 KPCC: conforms to Class B limits (a.k.a. NOT "overpowered")
91.5: KUSC (technically on Mt. Harvard, but on same mountain ridge with very similar coverage): somehow got an exemption to increase power, due to non-profit status and problems with interference from 91.7/Tijuana.
93.9: already was over Class B limits at previous lower site on Flint Peak, so it just lowered power to maintain same theoretical contours.
97.1 KNX-FM: same scenario as 93.9 (was already over Class B limit on Flint, so they went up in elevation but lost some ERP)
99.5 KKLA: another former lower-down signal, and this one was once 100kw. Again, higher height required much lower ERP.
100.3 K-LOVE: this was once around 50kw from the Briercrest site where KYSR still transmits, it moved up to Wilson in the early 1980's but now has far less power.
101.9 KSCA: was once nearly 100kw at lower sites. When they first moved to Wilson, they dropped to conforming Class B limits (around 600w), but later successfully argued their past approvals let them go up to about 4kw. I believe David Eduardo and/or Fybush have elaborated on this interesting history before.
105.9: another former Flint Peaker, running nearly 80kw. But just like 93.9 & 97.1, they dropped power (and possibly added directionally) just enough to maintain the same theoretical contour.
 
Gregg. said:
Yes, I would guess that 600 watts at 2,923 feet would put KPCC within Class B limits. When KSCA 101.9 was 640 watts at 2,830 feet, that one also conformed. But sometime in the last 20 years, KSCA's power got bumped up to 4,800 watts. That would be fine on the Sears Tower. Most Chicago FMs are around 4,000 to 6,000 watts. But 4,800 watts on Mount Wilson is now very overpowered.

KPWR 105.9 also got its overpower bump in the last 20 years. KPWR signed on in 1956. Most of its existence, 105.9 was 72,000 watts at 770 feet. Still overpowered but not as much as today. How did the FCC say in the 2000s, "OK KPWR. We will let you go on Mount Wilson at more than 3,000 feet. And you can do it at 25,000 watts. Class B regulations be damned!"
Click to expand...
KUTE (KSCA) 101.9 was originally on Flint peak as a "Superpower Class B" at 82 kW. When they moved to Mt Wilson, they temporarily lost their "Superpower" Class B status and had to run only 640 Watts. Eventually they were permitted to increase their Mt Wilson power to equivalent levels.
 
Sometime back, maybe two or three decades, it was decided that grandfathered stations could move and still maintain their grandfathered status. Before that, any move was only possible if they would drop back to(in these cases)standard Class B.
 
Interesting theory from Tomas. These FMs on Mount Wilson were already superpowered on shorter towers. As they moved up the mountain in height, they dropped their power an equal amount. So they simply kept the same height vs. power ratio. OK, I'm thinking about this.

I'm sure there's a mathematical formula for figuring out height vs. power. As I said earlier, Class B is supposed to be 50,000 watts at 500 feet. But when you go up on the Empire State Building, apx. 1,500 feet, you drop down to about 6,000 watts. And when you go up to Mt. Wilson at 3,000 feet, you drop to 600 watts. The decrease in power, in my mind, seems to be much more dramatic than the increase in height.

So I'm still having trouble seeing how standard Class B power is 600 watts on Mt. Wilson, while KNX-FM is 21,000 watts. That seems so much higher despite its previous superpower status at 750 feet.


Here are some listings from the 1965 Broadcasting Yearbook (Thanks to David for putting these books on line!) vs. the current-day info.

1965: ....................................................................................... 2023:
93.9 KPOL-FM - 100,000 watts at 550 feet ............ 93.9 KLLI - 17,000 watts at 3,009 feet
97.1 KFMU - 58,000 watts at 750 feet .................... 97.1 KNX-FM - 21,000 watts at 3,002 feet
99.5 KHOF - 100,000 watts at 240 feet .................. 99.5 KKLA-FM - 10,000 watts at 2,959 feet
100.3 KMLA - 58,000 watts at 1190 feet ............... 100.3 KKLQ - 5,400 watts at 2,917 feet
101.9 KUTE - 82,000 watts at 620 feet ................. 101.9 KSCA - 4,800 watts at 2, 831 feet
105.9 KBMS - 71,000 watts at 770 feet ................. 105.9 KPWR - 25,000 watts at 3,035 feet


.
 
Gregg. said:
So I'm still having trouble seeing how standard Class B power is 600 watts on Mt. Wilson, while KNX-FM is 21,000 watts. That seems so much higher despite its previous superpower status at 750 feet.
Click to expand...
Because 97.1 KNX-FM previously was grandfathered at above-Class-B power when it was on Flint Peak. When it moved up to Wilson, it just reduced power by a corresponding amount. 105.9 KPWR did the same thing (and dropped to approx. the same ERP) when it left Flint for Wilson.
 
Gregg. said:
Interesting theory from Tomas. These FMs on Mount Wilson were already superpowered on shorter towers. As they moved up the mountain in height, they dropped their power an equal amount. So they simply kept the same height vs. power ratio. OK, I'm thinking about this.

I'm sure there's a mathematical formula for figuring out height vs. power. As I said earlier, Class B is supposed to be 50,000 watts at 500 feet. But when you go up on the Empire State Building, apx. 1,500 feet, you drop down to about 6,000 watts. And when you go up to Mt. Wilson at 3,000 feet, you drop to 600 watts. The decrease in power, in my mind, seems to be much more dramatic than the increase in height.

So I'm still having trouble seeing how standard Class B power is 600 watts on Mt. Wilson, while KNX-FM is 21,000 watts. That seems so much higher despite its previous superpower status at 750 feet.


Here are some listings from the 1965 Broadcasting Yearbook (Thanks to David for putting these books on line!) vs. the current-day info.

1965: ....................................................................................... 2023:
93.9 KPOL-FM - 100,000 watts at 550 feet ............ 93.9 KLLI - 17,000 watts at 3,009 feet
97.1 KFMU - 58,000 watts at 750 feet .................... 97.1 KNX-FM - 21,000 watts at 3,002 feet
99.5 KHOF - 100,000 watts at 240 feet .................. 99.5 KKLA-FM - 10,000 watts at 2,959 feet
100.3 KMLA - 58,000 watts at 1190 feet ............... 100.3 KKLQ - 5,400 watts at 2,917 feet
101.9 KUTE - 82,000 watts at 620 feet ................. 101.9 KSCA - 4,800 watts at 2, 831 feet
105.9 KBMS - 71,000 watts at 770 feet ................. 105.9 KPWR - 25,000 watts at 3,035 feet


.
Click to expand...
Speaking of grandfather power. I'm surprised that KXOL 96.3 currently running 6,600 watts/1,306ft didn't move to Mt Wilson when they had grandfather power status of 54,000 watts at 483 feet. I forgot where there were transmitting from. I believe it was right by Dodgers stadium.
 
Gregg. said:
Interesting theory from Tomas. These FMs on Mount Wilson were already superpowered on shorter towers. As they moved up the mountain in height, they dropped their power an equal amount. So they simply kept the same height vs. power ratio. OK, I'm thinking about this.

I'm sure there's a mathematical formula for figuring out height vs. power. As I said earlier, Class B is supposed to be 50,000 watts at 500 feet. But when you go up on the Empire State Building, apx. 1,500 feet, you drop down to about 6,000 watts. And when you go up to Mt. Wilson at 3,000 feet, you drop to 600 watts. The decrease in power, in my mind, seems to be much more dramatic than the increase in height.

So I'm still having trouble seeing how standard Class B power is 600 watts on Mt. Wilson, while KNX-FM is 21,000 watts. That seems so much higher despite its previous superpower status at 750 feet.


Here are some listings from the 1965 Broadcasting Yearbook (Thanks to David for putting these books on line!) vs. the current-day info.

1965: ....................................................................................... 2023:
93.9 KPOL-FM - 100,000 watts at 550 feet ............ 93.9 KLLI - 17,000 watts at 3,009 feet
97.1 KFMU - 58,000 watts at 750 feet .................... 97.1 KNX-FM - 21,000 watts at 3,002 feet
99.5 KHOF - 100,000 watts at 240 feet .................. 99.5 KKLA-FM - 10,000 watts at 2,959 feet
100.3 KMLA - 58,000 watts at 1190 feet ............... 100.3 KKLQ - 5,400 watts at 2,917 feet
101.9 KUTE - 82,000 watts at 620 feet ................. 101.9 KSCA - 4,800 watts at 2, 831 feet
105.9 KBMS - 71,000 watts at 770 feet ................. 105.9 KPWR - 25,000 watts at 3,035 feet


.
Click to expand...
Don't forget 90.7 KPFK at 110 kW at 2831 feet
 
e-dawg said:
Speaking of grandfather power. I'm surprised that KXOL 96.3 currently running 6,600 watts/1,306ft didn't move to Mt Wilson when they had grandfather power status of 54,000 watts at 483 feet. I forgot where there were transmitting from. I believe it was right by Dodgers stadium.
Click to expand...
The FCC didn't issue their power limits (as a function of HAAT and zone) ruling until 1964. Before then it was the Wild West. However, FM was also a profit-free zone back then for the vast majority of broadcasters. That didn't start to change until after the ruling that broadcasters in the bigger markets (over 100K population, IIRC) couldn't simulcast their AMs and FMs more than 50% each day, which went into effect at the beginning of 1967. Most FMs didn't start seeing profits until the 1970s. The upshot was that many owners didn't have the money rolling in from their FMs, so they took the least cost, least effort path, which was to get on taller towers, reduce power and save on the electric bill.
 
Weiserguy said:
The FCC didn't issue their power limits (as a function of HAAT and zone) ruling until 1964. Before then it was the Wild West. However, FM was also a profit-free zone back then for the vast majority of broadcasters. That didn't start to change until after the ruling that broadcasters in the bigger markets (over 100K population, IIRC) couldn't simulcast their AMs and FMs more than 50% each day, which went into effect at the beginning of 1967. Most FMs didn't start seeing profits until the 1970s. The upshot was that many owners didn't have the money rolling in from their FMs, so they took the least cost, least effort path, which was to get on taller towers, reduce power and save on the electric bill.
Click to expand...
There were quite a few profitable FMs going back to the early 60's. Sol in LA, Jerry in Philly and quite a few others were profitable in the early 60's.

By 1966, I had two very profitable FMs in Quito, where I was asked "why would you want one of those?" when I asked for the licenses.

What I saw as the biggest impediment was that most FMs were owned by AM operators who did not want to create competition. After the "no simulcast" ruling, we saw lots and lots of profitable FMs, well before the 70's.
 
e-dawg said:
Speaking of grandfather power. I'm surprised that KXOL 96.3 currently running 6,600 watts/1,306ft didn't move to Mt Wilson when they had grandfather power status of 54,000 watts at 483 feet. I forgot where there were transmitting from. I believe it was right by Dodgers stadium.
Click to expand...
It was at the top of Montecito Drive, just south of the 110 Freeway on the center tower of AM 1150.
 
e-dawg said:
Speaking of grandfather power. I'm surprised that KXOL 96.3 currently running 6,600 watts/1,306ft didn't move to Mt Wilson when they had grandfather power status of 54,000 watts at 483 feet. I forgot where there were transmitting from. I believe it was right by Dodgers stadium.
Click to expand...
Back when 96.3 was religious KFSG (call letters stood for FourSquare Gospel), their antenna was on the 1150 AM tower just NE of downtown L.A. Many years later, 1150 moved to a diplex with 1020 AM in the City of Industry.
 
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