Is it possible for KJLH and KDAY to broadcast from Mt. Wilson

[wdb2003]

Just wondering why their signals are so limited around the area. I live in Pasadena off Foothill and I cant hardly pick any of them up?

 

[davideduardo]

Just wondering why their signals are so limited around the area. I live in Pasadena off Foothill and I cant hardly pick any of them up?

93.5 is second adjacent to KXOS and KCBS, which are on Wilson. Second adjacents can't be at the same site...

Same goes for KJLH with KSCA and KIIS.

In general, the separation between an A and a B on second adjacent is 42 miles, although the country is full of short spacings... but not ones that are next door to each other.

Further, 93.5 is at minimum separation with other 93.5 stations, particularly Ontario. 102.3 would have separation issues with the Victorville market and Palm Springs market co-channels, and the adjacent channel KPRI in San Diego... and so on.

 

[fybush]

Under certain circumstances, second-adjacents can be at the same site. KDAY was authorized in 1961, before the current FM spacing rules went into effect in 1964, and it's therefore grandfathered under the rules that existed before 1964. Those rules have no spacing restrictions between second- and third-adjacent FMs, so merely being second-adjacent to KCBS-FM and KXOS wouldn't prevent KDAY from moving up to Wilson. (KJLH is a bit more complicated; before 1964, and I'm not 100% certain that the current KJLH Compton license is the same 102.3 license that was KFOX-FM Long Beach pre-1964.)

But there are other rules that come into play here, too: pre-1964 grandfathered short-spacing doesn't apply to "IF spacing," the mandatory minimum spacing between FM stations 10.6/10.8 MHz apart. 93.5+10.8=104.3, so 93.5 has to stay at least 15 km away from KBIG. (102.3-10.8=91.5, so 102.3, if it could move, would have to stay at least 15 km away from KUSC, which is on Mount Harvard, 1 km or so from Wilson.)

There's a real-life example of pre-1964 grandfathering of a co-located second-adjacent: for a while, KMAX 107.1 Arcadia (or KSSE, or whatever it was at the time) operated from Wilson, right next door to KLVE on 107.5. It could do that because 107.1-10.8=96.3, and KXOL isn't located at Wilson.

So KDAY can move to Wilson, then? Not so fast...as David correctly points out, there are other rules that come into play. That pre-1964 grandfathering doesn't apply to co-channel and first-adjacent stations, so KDAY still has to protect 93.5s in Ontario and the AV, which it can't do from Wilson. And there's another factor at play, too: city-of-license coverage. KDAY has to put a certain signal level (70 dBu) over all of Redondo Beach, and Wilson is too far away to do that. (And you can't change KDAY's city of license, since KDAY is the only station licensed to Redondo.)

KMAX from Wilson was able to meet all those criteria, being fully spaced to 107.1s in Ventura and Fallbrook and fully covering its city of license, Arcadia, within sight of Wilson. But it had another problem: as a class A station operating from an extremely high antenna height, it had to derate its power so far (I want to say it was something like 90 watts from Wilson to equal the class A standard of 6 kW/100 meters) that it had almost no building penetration down below. Even the non-grandfathered Bs from Wilson (101.9, for instance, with 4800 watts, or 100.3 with 5.4 kW) have trouble getting enough "oomph" to penetrate buildings down in the basin at times.

So the short answer is: no, KDAY or KJLH can't move up to Wilson.

 

[davideduardo]

There's a real-life example of pre-1964 grandfathering of a co-located second-adjacent: for a while, KMAX 107.1 Arcadia (or KSSE, or whatever it was at the time) operated from Wilson, right next door to KLVE on 107.5. It could do that because 107.1-10.8=96.3, and KXOL isn't located at Wilson.

And when the KSSE site, currently part way up "the Mountain" (which I think is the Mt. Harvard side) was cut off by fire a number of years ago, they temporarily ran from the opposite end of the Wilson ridge from KLVE, but with under 50 watts. Needless to say, it could not get anything but in-car reception. Imagine either KDAY or KJLH with that kind of power... no penetration.

KRCV 98.3 had a similar, although nowhere nearly as extreme, case when on Johnstone Peak; it ran 570 watts and had an unusable signal over a huge area! There was literally nowhere that the station got any real listening. When it moved down to the SGV and upped power, it became a very competitive facility.

I wasn't aware that those pre-64's were not subject to the spacing rules... so few of them have the original facility and so many of the ones that are in major metros have the COL issue you refer to that I guess the subject does not come up often.

KXOL, which has rather tight directionalality, is fascinating. It had to move when evicted from the KPWR auxiliary site, and it moved farther away from the market's center of population. That one is tightly hemmed in because FSG Church never tried to improve the facility other than putting it at the old KRKD site.

 

[fybush]

I wasn't aware that those pre-64's were not subject to the spacing rules... so few of them have the original facility and so many of the ones that are in major metros have the COL issue you refer to that I guess the subject does not come up often.

You'd be surprised. Look at 94.3 in the Chicago suburbs - EMF did a very nice upgrade there by moving it from Joliet to Glendale Heights. It's still limited by spacing to 105.1 downtown, but it's now as close as it can get, covering a huge swath of the western and northwestern suburbs and much of the city itself.

And three suburban As have moved into (or closer to) NYC in recent years by taking advantage of the pre-1964 grandfathering: 93.5 and 103.9 from Westchester to the Bronx and, soon, 96.7 from Stamford CT to a new tx site in New Rochelle.

 

[jonbruce]

I think a class A on Wilson, given it's HAAT of aprox. 2900 feet would result in an ERP of close to zero watts. I can not recall 107.1 ever being on top of Wilson having lived in the L.A. area most of my life. I double checked David's great collection of Broadcasting Yearbooks and found 107.1 as KMAX went on the air Dec.3rd,1960 with 850 watts at -700ft. HAAT. Looking at the 1970 year book it is listed at 3kw -240ft HAAT and of course today 6kw -42ft so there is no record of it being on Wilson itself. I remember listening to it in 1965 when working in Long Beach. By the way, KJLH is the same license as KFOX 102.3. John Lamarr Hill purchased it from 1280 KFOX when KFOX bought 100.3 and moved it's similcast there. KJLH continued to use the tower on top of the old KFOX studios on Anaheim street for a number of years.