EAA AirVenture Convention

[melb]

Its been reported that a MOTOTRBO digital system is operating on 451.8875 at the airport in Oshkosh.

Is this MOTOTRBO system similar to a EDACS SCAT system?

 

[kc9fnm]

MOTOTRBO is a 2 slot 12.5kHz TDMA based system that uses an ABME vocoder from Digital Voice Systems Inc...the same people who brought you the IMBE vocoder used in the Apco25 protocol.

Not very scanner friendly.

Two time slots means one TRBO repeater can support two simultaneous voice conversations.
Its like two repeaters in one!
The radios can also do text messaging, gps/location stuff, call alert, ptt id, private call, group call...so on.

You could get a TRBO radio and program it, there are only 170,000 unique ID's... times that by two time slots = 340,000 possible combinations.

 

[newald]

Wittman Airport Frequencies:


http://www.baslerflightservice.com/eaa/eaafreqs.html


http://www.airventure.org/2007/flying/notam07.pdf

 

[a1emt]

I can confirm that the EAA Gate Security staff were all carrying MotoTRBO portables. The digital noise on that frequency sounded like a Motorola TRS control channel, but after locking my BCD-396 on it, no TRS system ID or audio was decoded... must be the TRBO. Anyone have a MotoTRBO portable to try monitoring the system?

On another note, the radio techs were trying for 2 days to get a repeater on 154.445 (Green Fire) to work. It kept dropping out and they appear to be back on simplex operation after it cut out a few times during an Alert 3 (crash) response on Tuesday. Not sure what the input to this repeater was.

Jim