How far can one realisticly receive ARTCC sgnals?

[fourthhorseman]

Im sitting here,catching transmissions fro what sees like way too far away.

I in central/western Massachusetts..roughly 650+/- feet above sea level,and my antenna's about 20ft off the
ground.Im using a RS 20-176 antenna on about 15ft of RG8X running SDR#..Also using the GRE Super Amp..Gain up full..

Ive been regularly receiving comm's..I look up the freq's and they are listed as the Bahama's,Houston,Miami,Mississippi

Is this common? Granted,Im probably catching the aircraft that are 10,15,17000ft alt..but Im also catching
faint comm's that seem like the ARTCC's responses..

Am I that lucky? or just getting the freq's mixed up?..

 

[ai8o]

You have just discoverd SPORADIC Es.
Go to HTTP://http://en.wikipedia.org/wiki/Sporadic_E_propagation for more info.

Also remember that given your stated antenna height and the fact that aircraft are routinely flying at 40,000 plus feet your local (24/7) radio horizon is in excess of 320 miles.

 

[KD9KSO]

Are you hearing the pilots checking in to the Center controller? IE, "Miami, American 775 checking in at 350 smooth" or something similar where you hearing the name of the ARTCC? They will check in each time they are handed of to another sector or to another Center controller.

I am 45NM southeast of KSTL. I have Indy, KCC, Chicago, and Memphis frequencies for the closest sectors to me. Some High Altitude sectors are a little farther out from me. I'm hearing aircraft as far as Memphis, Nashville, Springfield (IL&MO), Zanesville, etc.

Nothing like the distances you are hearing though. I'd say the farthest has probably been around 250 miles. That's from a handheld(s) with a Diamond (S)RH77CA indoors. It does a little better outside.

For the local area, I can hear pilots accepting the clearance for the QBALL and BOOSH1 arrivals before being handed off to the KSTL approach controllers.

 

[fourthhorseman]

Awesome!..Great link,Its remarkable the assistance the ionosphere will lend to signal propagation..
That wiki was a great lil read..This is my first experience with real skip..Living in the mountains helps too
I suppose!..

 

[scottymcneill8657]

Airband is one of the easier to listen to- I'm in huntingtown,md and can pick up new york with the standard ducky- I have roughly the same setup (using a tapped PRO-97 though) and can get south dakota at times- its a fun hobby because it doesn't take much to get a lot.

 

[AirScan]

Ive been regularly receiving comm's..I look up the freq's and they are listed as the Bahama's,Houston,Miami,Mississippi

What specific frequencies and flights are you talking about ? I'm very skeptical that you are actually hearing transmisions from that distance from your location ?

 

[scottymcneill8657]

I've gotten "132.05000 ZMP33 Sector 33 PIR Low" twice now- hard to hear but there- new york is reliably strong enough to pick up all the time. My antenna is 30ft above my house (the closest tree is about 50ft in any direction) and I'm on the top of a hill. My antenna is also tuned to about 140mhz running to an amp.

 

[popnokick]

ARTCC transmitters are commonly set up as remote base operations, with the controllers in a centralized facility but the transmitters/antennas located on mountaintops... sometimes hundreds of miles distant. Telephone lines and/or microwave relays carry the audio from the ARTCC facility to the remote transmitter locations. The air route sectors are usually quite large geographically, and the remote base enables ARTCC to ensure they are within VHF comms range over the entire sector.... and with alternate transmitters available. Pay close attention to freq listings for ARTCC sectors that include the location of the remote transmitter. And they are not going to be names you'll recognize right away, but obscure little towns/lakes or other geographic features located in or near the sector and the transmitter site.

 

[AirScan]

I've gotten "132.05000 ZMP33 Sector 33 PIR Low" twice now-

From Maryland ? Are you sure it wasn't Washington on 132.05 ? I haven't checked lately but there used to be a Washington Sector ZDC53 that used 132.05 in that area.

 

[fourthhorseman]

MichaleE..

Yes & No,,Im using SDR,so Im jumping to the freq's as I seem them pop up so some Im missing,Others are faint..But when I cross check the in the RRDB the far off ones will only list 1 maybe 2 transmission sites..

Its making me scratch my head,so I figured I post up and see what the RR members had to say..When I catch the flight number and carrier Im seeing the in the air from these wild distances..The aircraft's TX
is strong,,then followed by weaker transmissions..which I assume is the center responding..

I need to get an ACARS or ASD-B receiver set up so I can see who is up there..

 

[fourthhorseman]

What specific frequencies and flights are you talking about ? I'm very skeptical that you are actually hearing transmisions from that distance from your location ?

Sectors
19/Nucar- 123.675
61/Nassau-125.7
02/... 120.85
27/Picayune-126.8
47/Summer-124.075
19/Sinca- 123.95
25/Carlton-127.9
05/Hopkins-128.145

When Ive looked the up there were limited possibilities,Thus the posting of the original Q..
Everthing Ive caught so far is in the VHF120's130's..

Im in an area with almost no RFI...Antennas are outside and theres wide open skies! Im also pretty
elevated.

Maybe Ive got them wrong,but maybe I dont..Im hoping on the latter..

 

[AirScan]

fourthhorseman,

Am I that lucky? or just getting the freq's mixed up?..

I think you are getting the frequencies mixed up or they are not in the database you are using.

VHF reception range is line of sight, if you can see it you can hear it. The formula 1.23 times the square root of the altitude (feet) (above your antenna) can be used to calculate theoretical maximum line of site distance/reception range (nautical miles).

eg:

At 10000 feet reception range = 123 nautical miles
At 23000 feet reception range = 186 nautical miles

In my experience tropospheric ducting is extremely rare on the VHF airband. In around 30 years of monitoring I've probably heard it less than 5 times and it was only for an extra couple hundred miles and didn't last very long.

19/Nucar- 123.675
61/Nassau-125.7
02/... 120.85
27/Picayune-126.8
47/Summer-124.075
19/Sinca- 123.95
25/Carlton-127.9
05/Hopkins-128.145

This seems more likely as to what you are hearing ...

123.675 = Providence Approach
125.700 = New York Approach
120.850 = New York Approach
126.800 = New York Approach
124.075 = New York Approach
123.950 = Bradley Approach
127.900 = Cleveland Center
128.145 = I think you mean 128.150 ? Cleveland Center

Aircraft on the above frequencies would all be within "normal" reception range of central ma.

I need to get an ACARS or ASD-B receiver set up so I can see who is up there..

When you hear an aircraft on one of these frequencies you can use any number of flight trackers to see where it is.

FlightAware - Flight Tracker / Flight Status / Flight Tracking

Flightradar24.com - Live flight tracker!

 

[fourthhorseman]

Yeah,,I aware of the tracker sites,and yep,,I also aware of the RRDB..lol...

Using flightaware I was checking flight numbers that were corresponding to aircraft that were in the respective areas..Hearing the filght nuber,checking the freq & then double checking the flight,I was seeing a jetblu leaving Fla,over Georgia..

What DB are you checking these with?..When I punched the numbers up In the DB I set the search criteria to mass..So shouldn't it of showed me the RI info?

 

[AirScan]

What DB are you checking these with?

https://www.airnav.com/

 

[popnokick]

Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 7_1_1 like Mac OS X) AppleWebKit/537.51.2 (KHTML, like Gecko) Version/7.0 Mobile/11D201 Safari/9537.53)

There have been incidences of sporadic-E and/or tropo ducting recently in the FM broadcast 88-108 mHz band recently. 108-136 could be similarly affected. FM skip reported here:
http://m.radioreference.com/forums/GetThread.php?t=291577&f=96&bat=

 

[BMT]

ARTCC Freqs

Right now RR probably has the best on line list of ARTCC freqs.

BMT

 

[nd5y]

Right now RR probably has the best on line list of ARTCC freqs.

The locations of the remote sites is not always correct.
RRDB uses site locations from the FAA which in some cases has locations that are nowhere near where the sites are in real life. In a few cases people who know were the sites are actually located have submitted corrections to RR.

 

[fourthhorseman]

AIRNAV,,Great info,hoping to lookup and retag my findings..No doubt the local freqs im getting are good,but those long distance ones that I cannot verify via flightaware are the ones leaving me scratching my head..

Feels good when I get a comm and look it up and can nail it down,the distant ones I mean..

 

[reconrider8]

a sdr dongle with adsb works well to view the flights live also i listen with a scanner and then track the flights as they come over me

 

[BMT]

Most of the info came from each ARTCC.
We all know the FAA dB is as screwed up as a soup sandwich.

BMT