AIRINC 131.175 Mhz signal strength

[rayvelcoro]

I live close to a major airport. Why do AIRINC transmissions from planes seemingly way down range and in flight remain stable with regard to signal strength (I'm using a portable receiver indoors with the stock antenna)? Are these duplex conversations emanating from a repeater at the airport?

 

[nd5y]

Because unobstructed line of sight signals are like that. Line of sight path to an aircraft at high altitude can be well over 100 miles.

 

[AirScan]

Why do AIRINC transmissions from planes seemingly way down range and in flight remain stable with regard to signal strength

How far is "way down range" ? Can you hear the ARINC ground side of the transmissions ?

 

[nd5y]

duplicate deleted

 

[rayvelcoro]

Because unobstructed line of sight signals are like that. Line of sight path to an aircraft at high altitude can be well over 100 miles.

OK, good point. Thanks.

 

[rayvelcoro]

How far is "way down range" ? Can you hear the ARINC ground side of the transmissions ?

Thanks. Good question to consider-- now that you mention it, I may only be hearing the aircraft side of the conversations, which makes sense with the line-of-site 100+ mile idea.

 

[dlwtrunked]

As you did not define distaance, terrain, antenna height, etc., it is heard to define if you are "signal close" to the tower. Height though rules. I would not be surprised even for a 200 miles aircraft at altitude. But reception of a ground station, with not a tall tower and depending on terrain, might not be even possible at 20 miles.

 

[Gatorman]

ARINC transmitter/receive sites are not at every airport. The one in TN is in Nashville (BNA). Nothing here in Memphis. I had an AIRINC map that showed the ground stations and the freqs for the US and Caribbean. I will see if I can find it.

 

[andy51edge]

ARINC transmitter/receive sites are not at every airport. The one in TN is in Nashville (BNA). Nothing here in Memphis. I had an AIRINC map that showed the ground stations and the freqs for the US and Caribbean. I will see if I can find it.

ARINC (now Collins) publishes their radio network maps online. Found here at the bottom of the page under the "MAPS and DOCUMENTS" header.

 

[jsoergel]

ARINC (now Collins) publishes their radio network maps online. Found here at the bottom of the page under the "MAPS and DOCUMENTS" header.

I just submitted every CONUS site for ARINC to the database yesterday. Should be appearing in the DB within a few days' time if they aren't already there.

 

[littona]

Altitude does make all of the difference. From our dispatch center, we were able to talk to one of our helos about 130 miles away on VHF FM simplex. The aircraft radios only output 5 watts.