Discrete frequencies

[xayd01]

Where's the one that isn't discrete?

The Shirley MOAs (north of Little Rock if you look on the VFR charts) are used for low level C130 training. Those guys are flying around at 1500-3000 AGL all day long out there. And I did hear from a C130 instructor here at the LR AFB something about a new station coming online near Russellville that was going to help their ops, because they struggle to keep contact with ATC at the low altitudes they fly at and there was poor coverage out there.

 

[AirScan]

I did hear from a C130 instructor here at the LR AFB something about a new station coming online near Russellville that was going to help their ops

Interesting, I'll keep a look out for it.

Where's the one that isn't discrete?

Sector 15 Helena, frequency 135.30, basically extends between Memphis-Little Rock-Greenwood-Memphis. All the other sectors that cover Arkansas use single frequencies listed as discrete.

Are you familiar with the airspace southeast of Memphis ? That is where all those 2 frequency sectors are located. I presume they need more than one for geographic coverage but maybe they do split them vertically or do use the non-discete freqs as backup ?

 

[BMT]

DISCRETE FREQUENCY- A separate radio frequency for use in direct pilot-controller communications in air traffic control which reduces frequency congestion by controlling the number of aircraft operating on a particular frequency at one time. Discrete frequencies are normally designated for each control sector in en route/terminal ATC facilities. Discrete frequencies are listed in the Airport/Facility Directory and the DOD FLIP IFR En Route Supplement.

 

[BMT]

CONTROL SECTOR- An airspace area of defined horizontal and vertical dimensions for which a controller or group of controllers has air traffic control responsibility, normally within an air route traffic control center or an approach control facility. Sectors are established based on predominant traffic flows, altitude strata, and controller workload. Pilot‐communications during operations within a sector are normally maintained on discrete frequencies assigned to the sector.

 

[AirScan]

BMT,

The problem is the above definitions can also apply to frequencies that are listed as NON discrete.

Discrete frequencies are normally designated for each control sector in en route/terminal ATC facilities.

Again using the Memphis low sector 15 Helena as an example, 135.30 is the only frequency designated for this control sector, yet it is listed as NON discrete.

Discrete frequencies are listed in the Airport/Facility Directory and the DOD FLIP IFR En Route Supplement.

And 135.30 is published in the latest Airport/Facility Directory. Although it is not published on the IFR chart - this is the only consistent difference I can see so far.

 

[BMT]

Then you had better contact the FAA,because those definitions came from their web site!!

BMT

 

[xayd01]

Interesting, I'll keep a look out for it.



Sector 15 Helena, frequency 135.30, basically extends between Memphis-Little Rock-Greenwood-Memphis. All the other sectors that cover Arkansas use single frequencies listed as discrete.

Not related then, in all likelihood.

Are you familiar with the airspace southeast of Memphis ? That is where all those 2 frequency sectors are located. I presume they need more than one for geographic coverage but maybe they do split them vertically or do use the non-discete freqs as backup ?

Not really, when I was doing cross country hours in a rental I used to fly down to Camden and back from LIT, but don't really have a reason to go east of there except for family and friends either in New England or south FL, both of which are awfully far in a single ....

 

[sooner77]

128.475 is the freq ZME switches between Hot Springs, AR and Russellville, AR. ZME is always listening regardless. Same for 126.85 at Harrison, AR and Brinkley, AR. Same for 126.1 at Fayetteville and Fort Smith. Same occurs in Oklahoma with 132.2 McAlester and Okmulgee. I think that is what discrete means.

At N. Little Rock Airport 121.6 is clearance delivery from the KLIT Tracon but they do not always transmit on a continual basis. However, they are always listening for IFR aircraft wanting a clearance there. Same at Conway on 121.2.

 

[sooner77]

135.3 is at Wheatley, AR. See subcategory data for ZME.

 

[AirScan]

128.475 is the freq ZME switches between Hot Springs, AR and Russellville, AR. ZME is always listening regardless. Same for 126.85 at Harrison, AR and Brinkley, AR. Same for 126.1 at Fayetteville and Fort Smith. Same occurs in Oklahoma with 132.2 McAlester and Okmulgee. I think that is what discrete means.

I'm not sure what you're saying here ? A discrete frequency uses more than one transmitter ? Or a discrete frequency is always monitored ? Except there are many frequencies listed as discrete that only publish one transmitter site, and there are many non-discrete frequencies that appear to be the primary sector frequency that are always monitored as well.

135.3 is at Wheatley, AR. See subcategory data for ZME.

I see where it is, the databases list the RCAG site as Brinkley. I still don't see what distinguishes 135.30 as NON-DISCRETE ? (Except for the fact it's not published on the low altitude chart). The adjacent sector to the north, Sector 4 Jonesboro, using the single frequency 120.075 lists only one RCAG site at Walnut Ridge, and this frequency is listed as DISCRETE. So what's the difference between 135.300 and 120.075 ?

 

[sooner77]

Just a guess. 135.3 does not move around like 126.85 does between Wheatley and Harrison. The Walnut Ridge 120.075 probably is moved around to some other airport RCAG for IFR clearance in northeast AR-maybe Jonesboro? They are always listening. ZME moves 126.1 around depending where the reception is best. I thought that might be the meaning of discrete. For instance, when I was in North Bend, Oregon, Horizon Air would pick-up its clearance off of a discrete freq there that is normally at Horton, OR. Center listens on all of them, though may not be transmitting. Same thing with FSS and Tracons. North Little Rock, Searcy, Conway are similar discreets for IFR clearance purposes through the KLIT Tracon. 128.475 moves back and forth from KHOT to KRUE as required. If you listen to the KFYV feed liveatc you will hear one ZME controller working KHOT, KRUE and Fayetteville. Very late at night one controller will also combine 135.3 and the 120.075 at Walnut Ridge. BTW, will somebody put up a feed at Walnut Ridge for Center?--got all three tiers there according to radio reference. Jackson, TN has four ZME outlets. KTXK has three levels of ZFW. Maybe I am confusing it with decod, btw.

Center can move freqs around as necessary, btw, with the flip of a switch. I have heard 132.425 (KORK) and 132.55 (KFYV) in Fort Smith when ZME uses its BUEC system just on my handheld scanner with a rubber duck antenna. High power is involved as well as an unpublished RCAG site.

 

[AirScan]

Sooner77,

Just a guess. 135.3 does not move around like 126.85 does between Wheatley and Harrison. The Walnut Ridge 120.075 probably is moved around to some other airport RCAG for IFR clearance in northeast AR-maybe Jonesboro? They are always listening.

In the case of 120.075 that would mean an unpublished RCAG site somewhere ? I'm not familiar enough with ZME to speculate.

That it might mean discrete frequencies are always being monitored while non-discrete frequencies might be turned off seems like a possibility ? Although in the case of the non-discrete 135.30 this seems odd because it is the published APP/DEP control frequency serving 6 airports ?

I have heard 132.425 (KORK) and 132.55 (KFYV) in Fort Smith when ZME uses its BUEC system just on my handheld scanner with a rubber duck antenna. High power is involved as well as an unpublished RCAG site.

Interesting. Yeah they don't publish BUEC sites in the "standard" publications. I also see now that 132.425 is listed as discrete at the Little Rock RCAG and non-discrete from the Pine Bluff RCAG.

I'll check out that LiveATC feed when I get a chance, thanks for the info.

 

[sooner77]

125.475 and 132.425 used to be at Pine Bluff years ago. They moved them to a new site at KORK for sector and reception purposes. When I lived at KORK I noticed the airliners could not hear aforesaid freqs and complained quite a bit. Hence the move. There are unpublished RCAG sites used by ZME at Fayetteville and on Mount Magazine. At KFYV the Harrison ultra-high will occasionally "exercise" Buec on 133.025/284.75. On my feed at KFYV you will hear them on 284.75 which I have programmed in. It booms in. Two years ago thereabouts ZME left it on for three months, apparently doing maintenance at KHRO. I had all three tiers for the sector and it was fun to listen to. Seems to me the 133.025/284.75 is at the same location that the Jonesboro FSS transmits from at KFYV, plus Drake Tower. It is unpublished, but very close to the airport.. On a daily basis I will hear 126.1 in the Fort Smith area with my handheld for a certain period of time, then it goes back to KFYV. There used to be a non-discrete 119.25/380.3, for the F-16s I think, at KFSM, but it is gone now and replaced with 126.1/269.0. The F-16s are gone, too, dang it.

 

[AirScan]

Sooner77,

There are unpublished RCAG sites used by ZME at Fayetteville and on Mount Magazine.

Thanks for all the great info. and also for your LiveATC feed. Much appreciated !

 

[sooner77]

FYI,

Me and the wife were on Mt. Magazine, AR hiking Sunday afternoon, plus in the Lodge up there and I noticed 128.475 came in crystal clear. 128.475 is actually on Mt. Magazine, not at Russellville. We were walking around the Lodge in the lower parts of the building and I heard the ZME controller perfectly. I then spotted the antenna complex to the west with various cellphone antennas and so forth around it. Nice to know I can stay at the Lodge or cabins and listen in to the low controller when he/she is transmitting off of Magazine instead of the Hot Springs airport. Actually the controller was switching back and forth from Hot Springs to Magazine Mountain, just as he/she does from Wheatley to Harrison, Fayetteville to Fort Smith. Discreet or Decod? Anyhow, on my ride up the mountain to my place in Roland, OK, I heard 128.475 perfectly in the car with an outside window antenna. I also noticed 128.475 tells most KLIT traffic to DFW destinations to contact Fort Worth Center on 134.475 instead of using 132.425 at KORK. I always thought KLIT departures to DFW were handed off to 132.425 then to 134.475 at TXK. Learned something new.

 

[crayon]

The F-16s are gone, too, dang it.

A-10's need some love too.

 

[sooner77]

343.8 maybe or 254.4

 

[sooner77]

135.3 is at Wheatley. if you are in Little Rock, the tracon handsoff to 135.3 for aircraft going to the east/northeast. 120.07 is at Walnut Ridge RCAG with maybe an antenna at JBR. for IFRs. (DECOD).

 

[sooner77]

In reply to airscan, the Marshall freq is 128.125. I have been told by a man in MLC that 134.475 ZFW is at Talihina, OK. Perhaps maybe on Buffalo Mountain there. i can pickup the Morse Code from PGO VOR in my house with a telescoping antenna, but no controller on 134.475 atop that Talihina mountain in Roland, OK. Just do not know where 134.475 or 126.575 is even though I can hear the aircraft side on both. Neither freq is in MLC or TXK because I drove there and checked.

 

[BMT]

134.475 ZFW-42 McALESTER TX

126.575 ZFW-90 CUMBY TX

Sure would be nice if someone could confirm.

BMT