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KFI's NEUTERED STICK
- Thread starter sdwulfdawg
- Start date
As I understand it, their ATU had been upgraded a few years ago to only 25kw. The coax leading out there might not be rated for 50kw either, and since the path from the xmtr to that tower is parking lot it might be too much trouble to replace or temporarily rig it.
I wonder if their DX50 might balk at running full power into that undoubtedly narrower-bandwidth tower? (not that KFI is running much bandwidth these days!)
I wonder if their DX50 might balk at running full power into that undoubtedly narrower-bandwidth tower? (not that KFI is running much bandwidth these days!)
xoanon said:
The tower may not be insulated or capable of carrying the kinds of currents that 50 kw on what is about an eighth-wavelength stick; the ATu could have been replace cheaply but if the coax is burried and given the permits issues they have had on the stick itself, probably an issue.
Who cares what KFI coverage is after 9/14 when IBOC nighttime turns KFI's signal until "city grade contour" only. KFI's tower height or location will be of little concern in the new world of "local only" listening. A neutered stick is good enough to service Los Angeles. A taller KFI tower will just mean they will switch back on their HD. The rest of the country be damn, they don't need to hear a Los Angeles station.
Ray22 said:
Actually, it is not. It takes about 15 mv/m to get listenership to an AM, day or night, in its metro area. There is only minimal listening to large market AMs (NY, Chicago, etc) where noise levels are high outside this contour.
AMs want high power to saturate increasingly noisy metros, not to get unsalable listening outside the metro. In truth, listenership outside metros does not benefit stations, as they can not sell it. And skywave listenership is of almost no value, since both radio listening at night is much lower than daytime and most listeners no longer will put up with noisy, fading staticy signals.
There is no measureable KFI audience outside the groundwave coverage area, and hasn't been for decades. Essentially, nobody was listening anyway. And, again, the listening to AM at night is very low and mostly among the very old... young people who seldom use AM anyway definitely do not listen at night to distant stations.
It seems to me the best option is to put KFI on a Mt Wilson FM signal. The same can be said for any AM that still has ratings and brings in the cash flow. The AM band has so much going against it these days and AM IBOC will only do more harm than good.
radiorob2.0 said:
That is what is happening in many markets. However, publicly owned companies have to think about the potential for writedown of assest values if the intellectual property of an AM is taken to an FM channel. Closely held companies like Boneville have done this in Washington, DC, Phoenix and SLC. Cox, which is thightly controlled by one family, has started, too. And Clear has moved or launched conventional talkers on FM in Pittsburgh, New Orleans, Talahassee, Columbia (SC) and others. The reason, though, is mostly audience related... moving to FM opens up 35-54 audience that just will not tune to AM due to quality and other related issues like noise, etc.
On the other hand, I have listened to news and talk stations in several markets on my third generation factory installed HD radio, and those AMs sound magnificent and the HD signal extends far outside the home metro on those with reasonably good signals... like KNX or KFYI, for example.
Like any technologies you must prepare for a conversion period which could take at least a decade if not longer. The conversion will happen quicker if the new technology is available at a equal to/or lower cost compared to the old technology. I don't believe AM radio has a decade to ride out the change from analog to digital. Plus, HD radio is an option for receiver manufactures. So unless there is a consumer demand don't expect widespread availability.
Just want to clarify this new antenna is not "neutered". Because of top loading it is predicted to produce the same signal as the old tower.
Power handling and skywave protection are the two most likely reasons for reduced power operation on the back up antenna. The short antenna produces more high angle radiation which may increase interference to stations within about 500 miles. The short antenna probably also draws a huge amount of current compared to the taller antenna.
Power handling and skywave protection are the two most likely reasons for reduced power operation on the back up antenna. The short antenna produces more high angle radiation which may increase interference to stations within about 500 miles. The short antenna probably also draws a huge amount of current compared to the taller antenna.
FCC give the OK>
REPORT NO. 46572 B R O A D C A S T A C T I O N S 09/17/2007
AM STATION APPLICATIONS FOR MINOR CHANGE TO A LICENSED FACILITY GRANTED
-----------------------------------------------------------------------
Actions of: 06/14/2007
CA BP-20070201BSB KFI 34425 CAPSTAR TX LIMITED PARTNERSHIP Minor change in licensed facilities.
E 640 KHZ LOS ANGELES, CA
REPORT NO. 46572 B R O A D C A S T A C T I O N S 09/17/2007
AM STATION APPLICATIONS FOR MINOR CHANGE TO A LICENSED FACILITY GRANTED
-----------------------------------------------------------------------
Actions of: 06/14/2007
CA BP-20070201BSB KFI 34425 CAPSTAR TX LIMITED PARTNERSHIP Minor change in licensed facilities.
E 640 KHZ LOS ANGELES, CA
D
dbdigital
Guest
According to today's LA Radio, quoting the OC Register, the FAA is going to further study the possible hazard a new KFI tower would pose to pilots flying in and out of Fullerton Airport.
To quote LA Radio:
"Local pilots and Fullerton officials have strongly opposed plans to rebuild the tower to 684 feet. The old tower rose to 760 feet, according to the Register story. “Critics say anything taller than 500 feet would pose a high risk to pilots. Last Tuesday, the Fullerton City Council passed a unanimous resolution opposing the location and height of the tower.”
How much coverage would KFI lose with a shorter, 500 foot tower? Where else can they put their antenna?
db
To quote LA Radio:
"Local pilots and Fullerton officials have strongly opposed plans to rebuild the tower to 684 feet. The old tower rose to 760 feet, according to the Register story. “Critics say anything taller than 500 feet would pose a high risk to pilots. Last Tuesday, the Fullerton City Council passed a unanimous resolution opposing the location and height of the tower.”
How much coverage would KFI lose with a shorter, 500 foot tower? Where else can they put their antenna?
db
No place else without going directional or with much reduced radiation efficiency, I'm sure the engineering people have looked at that scenario.
I do not know how long that airport has been there, but KFI has been there since the 30's. Originally they had two 400' towers supporting a horizontal wire antenna of the type abandoned by almost all stations and especially the big 50KW flamethrowers many years before. They were replaced with the 750' vertical antenna in 1948 which was felled by a careless private pilot in December of 2004.
They have applied for a shorter tower 684 total feet above ground level which is actually less than than a half wave but would use a top hat to increase radiation efficiency by putting the higher current peak further up the tower. A 500' tower would only be 0.325 wavelength, more than a quarter wave but nowhere near their desired 1/2 wave. As far as I know, the FCC has signed off on the top hat design, so why the FAA is so concerned, after all of this cooperation is a mystery.
How much would buy the Fullerton Airport? Maybe Clear channel needs to ask.
D
dbdigital
Guest
nmoore6676 said:
As I understand it, the plane hit one of the guys. I wonder if a free-standing tower would be better or even feasible there?
As for buying Fullerton Airport, well, Clear Channel did just get a fresh transfusion of cash so maybe that would be an option. They could certainly buy Fullerton's City Council with that kind of money.
db
I understood that the highest guys were at around 650' so the last 100' or so was above that and the plane was said to have struck about ten feet down from the top. I doubt that a free standing tower would be feasible in that the area around the tower base has been developed into warehouses. A guyed tower has the advantage that in event of a complete failure the wires tend to pull the structure down and it collapses more or less on itself as the KFI tower did. Freestanding towers can fall over and farther away from the base.
Any structure that projects hundreds of feet into the air could present a hazard to unskilled amateur pilots who are not paying attention. To make it safe under those circumstances would create an unacceptable signal level which could not meet the FCC requirements for a station of KFI's class. In essence they would be surrendering their privilege which then could allow for other stations on adjacent channels (or co-channel stations) to apply for power increases or reduce their directional protection to KFI.
In this day of IBOC and all of the gadgets generating interference a station needs every millivolt of field strength to reach listeners on AM. It's not anymore about skywave and fringe reception it's all about getting over the background noise in the primary coverage area.
In this day and age it's almost impossible to put a new AM on the air because of how local governments are limiting owners with regard to transmitter sites, but to lose your site after being there for 60's years or more is ridiculous. Yes it's a hazard to air traffic, but one mistake by a pilot in all that time shouldn't stop them from rebuilding. With a shorter stick, daytime strobes and nighttime tower lighting in place as well as FAA warnings to pilots it should be safe..
D
dbdigital
Guest
nmoore6676 said:
Those are all good points.
I suppose this situation would be what a Kinstar antenna was designed for, a low profile antenna system. But if there are warehouses surrounding the KFI site, a Kinstar wouldn't work because the antenna builders would need the freedom to plant those poles where they would be most effective and not worry about dodging buildings. No doubt the contractors Clear Channel hired must have thought of every conceivable design (like adding the capacitance hat you mentioned for KFI's new tower).
Amazing how one accident can open up such a can of worms. And it highlights too the need for some new, innovative ideas in antenna design if AM is going to remain viable in urban areas.
db
The Kinstar antenna system only purports to have the efficiency of a 1/4 wave vertical radiater. It could not get KFI to their target groundwave strength as it would be only about as good as their auxiliary system. There is also the land use problem you mentioned. Now I understand that due to electrical limitations they can not operate at full power on the auxiliary tower and are limited to 25,000 watts, they did an upgrade last year to raise it from 20KW. The tuning system for the auxiliary is also too narrow bandwidth to allow them to use the IBOC transmitter.
The only advantage they can get from the low profile system would be getting back to full power with HD. But they might have to demolish some of the warehouses to make it work and still not produce the field strength to meet the original licensed specifications.
All of these use and permit issues are why more stations are now using diplexed AM facilities where two or more stations transmit on the same or some of the same towers in a shared array. I have to wonder though how this meshes with the more stringent regulations as to RF exposure. In the past the bigger the station the further from populated areas the transmitter. Usually the big 50KW flamethrowers were in remote farm land. WLW used to operate an experimental farm on the Mason site called "Everybody's Farm". There were live early morning broadcasts from the farm for the area farmers information and education. The extra land was likely a hold over from the 500KW experiment in the 30's. Now industrial and residential development is coming closer but of course their 500KW days will never come back. KFI used to be in the boonies as well and I think they were once among the stations seeking half million watt authorization.
dbdigital said:
nmoore6676 said:
There was an association of the 25 clear channels dating back to the 40's which tried to get the 1-A's to be authorized from 500 to 750 kw. The final decision against them was in about 1967, denying any appeal for reconsideration. By that time, the way radio was sold had moved to market based decisions vs. coverage based decisions, so the idea died then.... 40 years ago.
David:
With the hassles CC is facing, would it be possible to accept a less desirable situation for KFI, which still sounds fine in most of the TSA, and more easily seek a nighttime increase for WGST?
With the hassles CC is facing, would it be possible to accept a less desirable situation for KFI, which still sounds fine in most of the TSA, and more easily seek a nighttime increase for WGST?
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