JAX ARTCC RCAG in TALLAHASSEE

[JAXartcc1998]

I live 5 miles from JAX ARTCC RCAG location in Tallahassee. I can listen to both the pilot and controller 5 by5. At night, I understand how the controllers will combine frequencies all the time so you can hear the controller on multiple frequencies but the pilot only on ONE frequency.

What I don't understand is why there are times when I can hear the pilot on one frequency and not the controller. I’m only 5 miles away with an outdoor antenna. I hear the controller 5 by 5 most of the time, or hear nothing. It seems almost like the controller switched to a different RCAG location but using the same frequency because I can hear the pilot and he was never given a frequency change. It last happened when a controller could not hear an aircraft well. He did not tell the pilot to change frequency, but the controller switched transmitter location because I heard the pilot answer.

Can anyone help?

 

[AirScan]

It seems almost like the controller switched to a different RCAG location but using the same frequency

I'm not familiar with those sectors specifically but it's not uncommon for some sectors to use more than one RCAG location with the same frequency. Just curious what frequencies you are hearing this on ? Maybe note the location of the aircraft when you can't hear the controller and it might give you a general idea where the other RCAG might be.

 

[JAXartcc1998]

Thank you for the quick reply. I will make note of where the aircraft are when this occurs. The two sectors that do this are Sector 34 (Seminole) 128.07 and Sector 33 (Geneva) 125.05. .
I looked at the RCAG locations for JAX and could not find those two frequencies in any other RCAG location .

 

[JAXartcc1998]

Another theory I have is that the controller may be able to change from Omni directional to beam on his transmitter . You would think I could still hear the controller, just with weaker reception. Just a guess. .

As far as the Center changing RCAG (and use same frequency) is new to me

 

[alcahuete]

Another theory I have is that the controller may be able to change from Omni directional to beam on his transmitter .

That doesn't happen. There is no such thing as beam antennas used in ATC. They are all omnis out at the RCAG sites.

Each sector generally has 3 radios...Main, Standby, and BUEC. Main and Standby radios are located at the same physical RCAG site, but are two separate radios. The BUEC is at a completely different geographical location.

For Sector 33, the BUEC is in Moultrie, GA. For Sector 34, it is Bainbridge, GA. It is possible that the controller was using the BUEC radios, which you likely wouldn't hear up in Georgia.

As well, most centers are moving to CPDLC. That is datalink between the controllers and the aircraft, in which basically messages are sent back and forth with no voice communications. It is possible that the controller was using that, but the pilot likely wouldn't respond on frequency in that instance.

So my guess is that they were using the BUEC radios.

 

[JAXartcc1998]

That doesn't happen. There is no such thing as beam antennas used in ATC. They are all omnis out at the RCAG sites.

Each sector generally has 3 radios...Main, Standby, and BUEC. Main and Standby radios are located at the same physical RCAG site, but are two separate radios. The BUEC is at a completely different geographical location.

For Sector 33, the BUEC is in Moultrie, GA. For Sector 34, it is Bainbridge, GA. It is possible that the controller was using the BUEC radios, which you likely wouldn't hear up in Georgia.

As well, most centers are moving to CPDLC. That is datalink between the controllers and the aircraft, in which basically messages are sent back and forth with no voice communications. It is possible that the controller was using that, but the pilot likely wouldn't respond on frequency in that instance.

So my guess is that they were using the BUEC radios.

Thank you so much. That makes sense. I know about CPDLC and how controllers send messages and frequency changes to the pilot, but the pilot already checked in with the controller and had distorted radio transmissions,. So I think the controller switched to the BUEC radio because I lost the controller signal but still heard the pilot. I really appreciate your feedback. Thank you again.

 

[AirScan]

The two sectors that do this are Sector 34 (Seminole) 128.07 and Sector 33 (Geneva) 125.05. .

The RR Database for ZJX also shows 132.825 at Tallahassee but the FAA AFF file shows 132.825 in St. Augustine. Just curious if you can hear the controller on 132.825 as well ?

I looked at the RCAG locations for JAX and could not find those two frequencies in any other RCAG location .

The backup and BUEC locations can be hard to find, often you need to get a copy of the Center SOP (Standard Operating Procedures) documents. The copy of the ZJX SOP I have is a bit dated (2013) and for some reason they didn't include the RCAG and BUEC (Backup and Emergency Communications) locations in that edition. In this copy it does say the Standby and BUEC sites/frequencies should be tested at least once per shift.

I know about CPDLC and how controllers send messages and frequency changes to the pilot

If you wanted to get really hardcore you can receive and decode CPDLC comms using an SDR radio and software like dumpvdl2.

 

[alcahuete]

The backup and BUEC locations can be hard to find, often you need to get a copy of the Center SOP (Standard Operating Procedures) documents. The copy of the ZJX SOP I have is a bit dated (2013) and for some reason they didn't include the RCAG and BUEC (Backup and Emergency Communications) locations in that edition. In this copy it does say the Standby and BUEC sites/frequencies should be tested at least once per shift.

It isn't in the latest one either.

 

[JAXartcc1998]

ZJX does show 132.825 here at the Tallahassee RCAG but, I can never hear the controller, just the pilot. I believe it is an Ultra High frequency in Sector 87 (Lawtey) which is just SE of Sector 33 and the city of Tallahassee. They must have moved the location to St. Augustine. I can only hear the controller on 125.05, 128.07, and 128.62.

If the controller is required to check the BUEC frequency one per shift that will explain why that occurs often. I thought maybe weather like severe thunderstorms would cause Interference making them switch. It all makes perfect sense now.

I’m definitely interested in the decoding of CPDLC messages. I will check into a SDR radio and software. Thank you for your support and information.

 

[AirScan]

ZJX does show 132.825 here at the Tallahassee RCAG but, I can never hear the controller, just the pilot. I believe it is an Ultra High frequency in Sector 87 (Lawtey) which is just SE of Sector 33 and the city of Tallahassee.

Last time I checked 132.825 was Sector 87 (Ultra High). If you don't have them already I've attached the sector charts (2019) I have for ZJX. I can't remember the source, I think someone posted them on one of the forums somewhere, so I can't confirm their authenticity but from what I've heard they look accurate.

I can only hear the controller on 125.05, 128.07, and 128.62.

The RR Database shows 128.625 in St. Augustine but also lists it as a Tallahassee Approach frequency, while the FAA show it in Tallahassee but list it as a Low/High frequency, while the sector charts and RR Database show it as Ultra High Sector Sector 85 Micanopy. Can you confirm that 128.625 is only used as the ultra high (FL350 and above) frequency ?

Last time I checked this Sector 85 would only be used when required, otherwise it was combined into the the sector below it (Sector 17 Perry) and 135.625 would be used to cover both sectors (Day Shift), not sure what the Night Shift configuration is ?

Sorry for all the questions, I maintain my own database for ARTCC info. and often there is conflicting or incomplete info. between various sources, so reports from actual monitoring are very helpful.

If the controller is required to check the BUEC frequency one per shift that will explain why that occurs often.

Depends how often you are hearing this happen ? If it happens quite frequently I'm not sure testing a BUEC site would explain it completly. In my experience when they do test BUEC sites they often ask the pilot for a radio check, something like "Delta 1655 Jacksonville Center how do you read on this transmitter".

I suspect that maybe if you are hearing this quite frequenctly it might have more to do with sector configuration and area coverage. In addition to aircraft location try and note how they have the sectors configured. For example have you noticed if they ever combine Sector 33 and 34 ? Most ARTCC SOPs list the sector confirguations but the copy of the ZJX SOP I have doesn't have that either, so again any info you have is helpful.

 

[AirScan]

Can you confirm that 128.625 is only used as the ultra high (FL350 and above) frequency ?

Just checked my notes and I see the last time I checked (LiveATC) they did use 128.625 as a Tallahassee Approach frequency, but only on the overnight shift. Maybe they are combing all sectors into 128.625 on the overnight shift ? Can you confirm then that 128.625 is used as the ultra high frequency during the day then ?

 

[JAXartcc1998]

The sector charts you attached are a huge help. They look very accurate to me. Thank you. For Sector 85 (Micanopy) , 128.625 is definitely used as an Ultra High Frequency (350 and above) as well as Tallahassee approach only after 2300 hrs when the TRACON is closed. When there is less traffic ATC will only use 135.625 Sector 17 (Perry) for that airspace. I can’t hear the controller on 135.62 but ZJX is also transmitting on 128.625, so I use two radios to hear the traffic. As far as sector 33 and 34 combined, it does happen, it is usually for only short periods of time when it’s not busy. For example in the morning before 10am, after that they are split due to heavy traffic. Or like a Saturday afternoon with little traffic

I’m glad you keep a data base for ARTCC. Please feel free to ask any questions about ATC you have . I’m sure I will have more .

 

[JAXartcc1998]

As far as the overnight shift , I believe all sectors in this area use Sector 34 128.07. I will confirm that tonight for you. I have heard ATC hand off an aircraft from 128.07 to MIA ARTCC 133.9 in SRQ after midnight.

 

[AirScan]

Thanks for the info. Attached are my High Altitude chart notes in that area. My intent is to make a sort of quick reference chart depicting frequencies/sectors and typical configurations used during the day shift. If you see any changes or have any comments please let me know. I'm still working on a Low Atltiude and a Military/UHF version. Do you monitor milair UHF at all ?

 

[JAXartcc1998]

I have a radio to pickup UHF and military frequencies but here in Tallahassee I don’t hear much. The restricted airspace in the Gulf might be too far to hear .

 

[JAXartcc1998]

The high altitude charts are perfect . I love them and will print them out.

 

[AI7PM]

That doesn't happen. There is no such thing as beam antennas used in ATC. They are all omnis out at the RCAG sites.

Not entirely true. Some coastal sectors (I guess not ZJX) do use Yagi or Corner Reflector directional antennas aimed off shore. Seattle TRACON used a Yagi at Sea-Tac aimed at Olympia many years ago. It became a backup once radios were added to the existing Olympia RCAG. ARINC has some directional VHFs as well.

 

[JAXartcc1998]

That’s good to know. Thank you for the information.

 

[JAXartcc1998]

I checked after midnight local time and Sector 34 128.07 seems to be the main frequency. JAX was handing off aircraft to ZMIA on 128.22 (Sarasota RCAG).

 

[alcahuete]

Not entirely true. Some coastal sectors (I guess not ZJX) do use Yagi or Corner Reflector directional antennas aimed off shore. Seattle TRACON used a Yagi at Sea-Tac aimed at Olympia many years ago. It became a backup once radios were added to the existing Olympia RCAG. ARINC has some directional VHFs as well.

ARINC is not ATC. TRACONs do not use RCAG sites. The RCAG sites use omnis. There is no reason for yagis at coastal sectors...the omnis easily cover out ot 250+ nm with aircraft at altitude.