Messages

1

General Discussion / Re: NMEA out to transponder.

« on: October 31, 2015, 04:29:09 pm »

Sorry Lee, I have been out all day and only just seen your question. I am afraid that I have to agree with Richard re lack of any info in the manual so can't help. Hopefully Trig will provide you with the answer.
Mike

2

General Discussion / Re: NMEA out to transponder.

« on: October 30, 2015, 09:47:11 pm »

I have a Trig TT21 and include below the section from the Installation Manual which details the requirements for GPS input. It looks as though it can accept a number of different protocols but the NATS Non Certified GPS Trial information document states the following requirements for the GPS:

"As a minimum, any GPS that outputs
NMEA 0183 sentences over an RS-232
link."

It looks as though using the NMEA protocol sets the required SIL and SDA values for the trial on many transponders.

Mike

*****Extract from Trigg TT21/TT22 Installation Manual*****
5.6.9 GPS Position Input
The GPS position input is required to support ADS-B functionality. The GPS
position input is an RS232 input to the transponder. The ADS-B features are
optional – no GPS is required for normal Mode S Elementary Surveillance.
The TT21/TT22 GPS input can recognise the following protocols:
    Industry standard “Aviation” protocol
 NMEA 0183 protocol
 Freeflight and Accord NexNav GPS proprietary protocols
 Garmin ADS-B protocol, including ADS-B plus
 Trig ADS-B protocol
 C199 TABS compliant GPS using NMEA protocol
The interface speed can be selected between 4800, 9600, 19200 and 38400
bps.

3

General Discussion / Re: Can I test half built?

« on: October 22, 2015, 05:34:37 pm »

Mine is working perfectly without the radio board and regulator fitted just the DVB-T and WiFi dongles connected. Sitting the aerial on an old tin tray is giving plenty of traffic. Don't forget to set the Sky Demon up to show contacts at 40,000' or more as most will be commercial jets at high altitude.
Mike