Re: Can Flash Move?--It can, but it wouldn't improve things much in Sacto.
Ted,
Can you shoot me an email timmywa(at)gmail(dot)com?
Interested in more info...
-Timmy
> Hi, Timmy--
>
> To directly answer your question:
>
> While it may SEEM that there are vacant dial positions, the
> vacancies are part of an interference protection
> system--buffers designed to let you receive a station within
> its protected coverage area and not have have it blown away
> by other stations on the same channel or on ones on either
> side.
>
> Essentially, there's no room between 92.5 and 93.7 to put
> another station in the Sacramento region.
>
> That's due to the need to protect the interference free
> coverage areas of 92.5, and 93.7, (and other stations.)
>
> 92.5 gets co-channel protection on 92.5 out for so-many
> miles, and first, second and third adjacent channel
> protection from interference from stations on 91.9, 92.1,
> 92.3, 92.7 92.9.
>
> There's a 91.9 in Chico, 92.1 Placerville... and other
> stations that bump into each other's protection zones.
>
> 93.7 gets co-channel protection and first, second and third
> adjacent protection from interference from stations on 93.1,
> 93.3, 93.5, 93.9, 94.1, and 94.3. You can identify several
> that are within earshot of Sacramento, that would have some
> kind of protection from any new stations.
>
> That's the basic situation. Keep reading for more detail
> and some minutia if you want to.
>
> Here's generally how the FCC allotment scheme works:
>
> There are several "classes" of stations, each designed to
> serve comparatively larger or smaller geographic areas.
>
> Transmitter sites are located where they'll:
> A: Put the legally required signal strength over the entire
> community of license, and
> B: Not interfere with other licensed stations within the
> other stations' protected coverate areas.
>
> You may find a lot of sites that will do A but not B, B but
> not A, or neither.
>
> With more stations on the dial, finding one to do both is
> much harder to do, especially as more are licensed in fringe
> areas around a major market.
>
> Stations get protection from "co-channel" intereference
> (stations on the same frequency) and "adjacent channel"
> interference (stations three channels up and three down from
> the station you're talking about.)
>
> The FCC uses specific amounts of mileage between
> transmitters and limits on the ERP (Effective Radiated
> Power) and antenna height to make it work.
>
> The mileage separation required is greatest for "co-channel"
> stations, and lessens as you go to first, second and third
> adjacent stations.
>
> Class C stations are the most powerful, and have the largest
> protected coverage. Some use as much as 100KW ERP from
> nearly a thousand feet above average terrain before they
> have to reduce ERP (power) to stay within their protected
> area and protect other stations on the same channel and up
> to three channels either side.
>
> If the stations DIDN'T cut power as its antenna went above
> the maximum, its coverage area could expand enough to
> interfere with the protected coverage areas of other
> stations.
>
> (You can check the actual heights at
http://www.fcc.gov.
> I'm being pretty general here... so guys who can quote the
> specs, please do so but don't shoot he messenger.)
>
> Class B's are less powerful... often 50KW with maximum
> antenna height of almost 500 feet above average terrain
> before power reduction is necessary.
>
> Class A's like 103.9, 92.1 and KBMB are limited to 6KW at
> 328 feet above average terrain before they have to reduce
> ERP.
>
> As stations were added over the years, the "incoming"
> stations had to respect those protected areas, while trying
> to serve their prospective community of license (COL) with
> the legally required signal strength.
>
> That acts like a rubber band, forcing the the station to
> stay physically close to its COL,(which it is SUPPOSED to
> serve) while the protected coverage areas of other stations
> act like balloons keeping it away from their markets.
>
> It becomes a big PITA trying to find a geographic
> transmitter location that will work to cover a bigger market
> from off to the side, as various "rimshot" stations like
> 103.9 and 92.1, 105.5 and others try to do.
>
> Moving North, East, South or West, an engineer has to make
> sure any first location or relocation keeps his COL properly
> covered and doesn't cause interference to other licensed
> stations.
>
> That's why 103.9 was moved to Lincoln in an effort to get
> the stick closer to Sacramento downtown. The Sutter Buttes
> or South Sutter Co. didn't do what the owners or buyers
> wanted... and there are limits on how close to Sac the stick
> can go because of protection for 103.5 (among others.)
>
> I liken this to a chess game, because there are certain
> moves for pieces that at first look good or possible, but
> looking again, you find the trap.
>
> 92.1 Placerville can move only so far west before it runs up
> against the second adjacent protected coverage areas of 92.5
> in Sacramento and the non-commercial stations on 91.5, 7 and
> 9 and 92.1 Walnut Creek's protected coverage area.
>
> Because of the mileage involved (actually, the lack of it)
> protecting KGBY, 92.5, Sacramento is the limiting factor.
>
> 92.5 "blocks" any further westward movement for 92.1, and
> the distance from the stick to many parts of the Sacramento
> market keeps the signal strength from being ideal.
>
> And that's why you'll not find a whole lot of "improvement"
> possible for 92.1 when it comes to "serving" Sacramentans
> instead of Placervillians, for whom the station was licensed
> in the first place.
>
> For other examples of mileage separation blocking an
> upgrade, go back into First Broadcasting's history in the
> area and another set of Class A's:
>
> KNGT, 94.3 Jackson was co-channel to KNCO-FM, 94.3 Grass
> Valley. Mileage restrictions prevented First from moving
> the KNGT transmitter to a site more advantageous to reach
> Sacramento. In order to pull it off... First struck a deal
> to buy KNCO-FM... but then the sellers thought again and
> backed out of the deal. (Hurrah!) They took significantly
> less money to move KNCO-FM one notch down the dial to 94.1,
> and kept the Grass Valley station programmed from Grass
> Valley for Nevada County residents.
>
> That deal let First get wheels moving on the transmitter
> upgrade, resulting in the sale of KNGT for a big profit to
> Hispanic Broadcasting.
>
> Several sales/trades later, the Jackson station's speaking
> Spanish again.
>
> Same kind of thing happened with First and 103.9. That shell
> game worked out better for 103.9 because the COL was moved
> to Lincoln, and First found a sweet transmitter site with a
> straight shot into Sacto, where the average terrain was just
> below the point where it would have had to drop ERP below
> 6KW.
>
> You mentioned 93.7:
>
> What's now 25KW Class B1 KHWD, 93.7, Roseville was
> originally a Class A station, at 3KW before the max power at
> max antenna height was raised to the current 6KW. Back then,
> it broadcast from a tower on Rosebud Lane off Auburn Blvd.
> northeast of Madison Ave.
>
> As KRXQ "93 Rock," the owner wanted to jump to a 25KW Class
> B1 facility. The ability to do that was tied to changes in
> the facilities used by KFMF, Chico... which affected
> co-channel and adjacent channel coverage area interference
> protection for both stations.
>
> If I recall correctly, Fuller-Jeffrey owned KRXQ at that
> point, and I think it owned KFMF, also, which (would have)
> made certain aspects of the upgrade easier to achieve,
> because there was only one owner in the mix... not two.
>
> I hope the first part answered your question... and the
> balance was educational.
>
> Ted.
>
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