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LONG DISTANCE AM STATION MOVES

S

stereolane

Does the FCC still allow AM stations to be moved a long distance? Several years back, I recall seeing applications to relocate a handful of AM stations hundreds of miles from their original COL.

With AM in such dire straits, if the engineering worked, would the FCC still consider this?
 
I believe only if the "new" station is mutually exclusive with the existing, I think there is also some prohibition about removing a city's only service, and that the new site/col must provide more first service than losing the existing 1 takes away.
 
With so many neglected, barely ran AM's on the air, I wish they would come up with some sort of incentive to restructure the band to be all full timers. I know it will probably never happen...

But it would be nice to rework AM in a way that allowed good spacing and the proper audio quality.
 
There was a station in Opp, Alabama (WAMI-AM, I think), that applied many years ago to relocate to Kanab, Utah. They also filed to change frequencies.
It was dismissed earlier this year, because nobody answered some FCC queries about the proposed tower location. I guess the owners just gave up on it.

I like the idea of restructuring the band, to all full-timers.
 
I think that was a one-time event during an application window of something like 10 years ago.

I have hear comments (of unknown viability) that it will never be allowed again.

I think the pattern was this: The FCC no longer accepts applications for NEW AM CPs that are daytime only. If you can't work in at least a handful of night-time watts, station will not be approved.

All the stations that filed for long-distance transfers were DAYTIME ONLY. Their DAYTIME ONLY feature was considered to be grand-fathered in.

If the geography in the distant community will make room for a new station with night-time hours, there is no need to buy someone's junk a thousand miles away and transfer it in. Just build new. (They were not moving the frequency, just the grandfathered rights to day-time only, on whatever frequency was available.)
 
I'm not so sure the prohibition on removing a city's only service is applicable to AM stations.

Definitely, it's not necessary for the new facility to be mutually exclusive with the existing. However... if it isn't, then you must wait (YEARS) for a filing window, and you must compete with applications for completely new service. But as GRC suggests, if a new full-time station is not possible at the new site, then moving an existing daytimer is the only way to get new AM service there.

Educational Media Foundation just succeeded in moving a non-commercial FM from Oberlin, Kansas to Carbon Hill, Alabama. I have no idea why they didn't just apply for a new station in Alabama.

_________________________________________________

GRC: the FCC will not accept applications for new Class D stations. (see 73.21) Class D stations are defined as those with night powers of less than 250 watts or a nighttime field of less than 141mV/m @ 1km.

Point being, being able to run "...at least a handful of night-time watts,..." is not enough to be classified Class B & get a new license. You have to be able to reach 250 watts night.

Not that that really invalidates your point.

(I guess 141mV/m @ 1km is the field delivered by 250 watts into an antenna of minimum efficiency. Some stations may be Class B with less than 250 watts night power, if their antennas are unusually efficient. There's a Class D station in Illinois running only 135 watts *during the day*; obviously their antenna is particularly efficient!)

_________________________________________________

I concur with the suggestion the AM band should be cleared of Class D stations. (also, Class B's that don't reach, say, 90% of the population of the market)

However, that would require deleting thousands of stations -- something that would be politically & legally impossible.

The Commission should never have licensed daytimers in the first place.

(Over the last few days I've been dreaming of being the Commissioner who, in 1946, convinced the rest of the Commission to refuse to issue daytime-only licenses. Engineers have strange dreams.......)
 
My daytimer has a big daytime signal, but it's not very useful anymore in it's current location. The Opp, AL to Kanab, UT move is the type of move I was referring to.

I'm trying to examine all available options.
 
w9wi said:
Point being, being able to run "...at least a handful of night-time watts,..." is not enough to be classified Class B & get a new license. You have to be able to reach 250 watts night.
Click to expand...
There are Class B stations with less than 250 watts at night, such as 1510 WRNJ in Hackettstown, NJ, licensed as 2000 watts daytime, 1100 watts critical hours, and 230 watts nighttime.
 
satech said:
w9wi said:
Point being, being able to run "...at least a handful of night-time watts,..." is not enough to be classified Class B & get a new license. You have to be able to reach 250 watts night.
Click to expand...
There are Class B stations with less than 250 watts at night, such as 1510 WRNJ in Hackettstown, NJ, licensed as 2000 watts daytime, 1100 watts critical hours, and 230 watts nighttime.
Click to expand...
Chances are they were a daytime only station at one time and that is their night power allotment that most, but not all daytimers received back in the 80's. The lucky ones got 250 watts and protection. The ones below 250 watts (like WRNJ) have no protection. Someone else on that frequency can make changes that would affect WRNJ's night power and WRNJ would have no way to stop them--unless they modified their antenna before someone else attempted a change so as to get their night power at or above 250 watts.
 
Class B AMs must show nighttime power of at least 250 watts or equivalent field strength from a more efficient (electrically taller) antenna. WRNJ shows nighttime field strength of 141.73 mV/meter, which just barely qualifies for B status.
 
w9wi said:
I guess 141mV/m @ 1km is the field delivered by 250 watts into an antenna of minimum efficiency. Some stations may be Class B with less than 250 watts night power, if their antennas are unusually efficient. There's a Class D station in Illinois running only 135 watts *during the day*; obviously their antenna is particularly efficient!
Click to expand...

Nobody has mentioned that, to be authorized as a Class B, and AM must also deliver an NIF (nighttime interference-free) signal to at least 80% of the population of the CoL. An ID (inverse-distance) field of 141 mV/m @ 1km is necessary but not sufficient. In many cases the only way to meet the NIF requirement is to change the CoL, but if that option is not available, even if 141 mV/m causes no prohibited interference to another AM, the station that desires the upgrade will have to remain a Class D.
 
There were a couple of wacky ones. The 560 in Yuma AZ had an app. to move into the Las Vegas NV market, and the longest one I saw was the 1550 in Morris, Il changing freq.'s to 670 and moving to the Tucsan AZ area.
 
andydallas said:
I guess I"m wondering why do they bother to "move" a station, why now just an application for a new station?
Click to expand...

To simplify the numerous highly technical points in this thread :) :

1. The FCC used to authorize Class D stations -- AM stations which were only allowed to operate during the day. Hundreds of these stations were licensed over the years.

2. The Commission no longer authorizes new daytime-only stations. A new station must be able to deliver at least a minimum signal strength ("141mV/m @ 1km") both day & night in order to be licensed. However, the existing daytime-only stations are allowed to continue to operate.*

3. The AM band is VERY crowded, especially at night. In many areas, it is simply not possible to build a completely new station that delivers the necessary minimum signal at night, without interfering with something else that was already there. It is simply not possible to license a completely new station at these sites.

4. The FCC does allow you to *move* an existing daytime-only station to a new location.



So, let's say you want to launch a new station in Northbrook, Illinois, in suburban Chicago.

You check, and find there is no frequency where a new station could deliver the necessary minimum nighttime signal. However, you *could* deliver the minimum signal *during the day* if you operated on 1550.

So, you buy an existing daytime-only station in some other city -- say, Lake Geneva, Wisconsin. Because this station was licensed before the rules changed, it gets to keep its daytime-only license. You ask the FCC to allow you to move your station from Lake Geneva to Northbrook -- and assuming you prepared your application properly, the FCC says "yes".

_________________________________________________

* Technically, most Class D stations are no longer limited to daytime operation. However, they are restricted to very low nighttime powers, not enough to deliver the minimum nighttime signal that would be required of a new station.
 
The FCC opened a filing window for AM station major changes sometime back. Some enterprising folks discovered that it would be an opportunity to move existing daytimers closer to larger cities in places where a full time station could not be engineered in. Hence the number of applications for long distance moves that would not ordinarily be allowed.
 
WRNJ used to be on 1000 kHz. Larry Tighe tried for years to find a frequency for fulltime, and ended up moving to 1510. He was behind several attempts to expand FM service to new bands of frequencies to replace AM daytimers. One was 225 to 230 MHz and another VERY unpopular one was eliminating the 6 meter amateur band for more FM channels.

Any Class B is protected at night to the NIF. The theoretical minimum power with a single 5/8 monopole is somewhere around 110 watts.

A very efficient endfire array with 0.5+ wavelength towers spaced 90 degrees or less could theoretically operate with even less than 100 watts and have an efficiency of 141 mV/m inverse field at one kilometer. The power is squeezed into the horizontal by the perpendicular or near perpendicular nulls.
 
If R. Fry or anyone else reading this has a 1960 NAB Handbook, look up the graph that shows various spacings and phases of two towers and the theoretical RMS of the pattern produced, and it would show how you might construct an array that allowed less than 250 watts with ~0.25 wavelength towers to have 141 mV/m inverse field at one kilometer efficiency. It's in the chapter on designing AM DAs. Rich, if you could please copy that graph and email it to me also. You have to convert to miles (87.5 mV/m inverse field at one mile), and remember that the actual efficiency is a little less than that shown. It's about 2% less than thetheoretical with 120 standard radials.
 
Thanks, David. The last time I looked, you just had the 1949 Edition. The graph was prepared by Carl Jones, of AM DA Radio Consulting fame. He designed the WGAR 1220 and WTVN 610 arrays, to name two in Ohio.
 
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