I suspect that if you line up too much stuff on the roof along a specific axis relative to the TCAS antenna, all that extra metal will affect the attenuation pattern in different bearings. For example if you put some metal items in front of the TCAS antenna, it may see signals from straight-ahead attenuated more than from other bearings. This would then affect the way the target bearing is computed because all these active systems use four antennae (two resolving front/back and two resolving left/right).
It may also mask traffic from a particular bearing so it won’t appear until it is very close. My TCAS has this issue at 12 o’clock and often doesn’t pick up traffic until it is 1-2nm away. But when you look at my post-installation roof pic here you can see the probable reason for it.
… but they only mention GPS antennas – your theory should be valid for other antennas as well as other axis, too …
@Peter, @wigglyamp, @ValerioM
@eddsPeter wrote:
Looking on the Garmin pages that seems not to be true. With the GTS800 you will get ADS-B in. To get ADS-B out you need to upgrade the GTX330 transponder to the GTX330ES. No need for the GTX345.
Reading Peter question with TAS610 from Avidyne, I wonder how works the GTS800.
Does it natively receive and merge ADSB (in) target ? Who has tried this ? @Bobo maybe ?
About ADSB out. How a GTX330ES can be enough, if there is no approved position source (WAAS) ?
GTX345+WAAS would solve the problem in this case if I understand properly.
Back to GTS800: will ADSBin work, if ADSBout is not active ? Would be really pleased to see a photo of an MFD screen showing GTS800 mixed input.
I have the GTX330 and I have not tried to upgrade. Something for the future maybe. I get ADS-B in on the GTS800.
@Bobo wrote:
I get ADS-B in on the GTS800.
Ok, that was my question.
So, natively, the GTS800 offers ADSB and C/S targets.
What MFD display do you use ?
Would you mind posting a photo with different targets ? (ADSB and XPDR)
I use a GNS530W, don’t have any pics of the traffic page right now. I do understand now why some install two GNS’s. I find myself flipping through the page more often now.
The manual has some grafics: http://static.garmin.com/pumac/190-00587-02_E.pdf
A screenshot from earlier today. ForeFlight with SkyEcho on an iPad Pro in an ADSB environment. At the time of screenshot there is a georeferenced overlay of the appropriate STAR.
I have a gts800 in my rv7, with the two-fins antenna mounted upsidedown on the belly (before anybody asks, yes I see traffic all around me, even straight above and in front of the plane). Not an expert about traffic systems but when I did my survey 2 years ago I quickly understood that in Europe you have to go for the expensive stuff to actually see other GA traffic.
Dave_Phillips wrote:
A screenshot from earlier today.ForeFlight with SkyEcho on an iPad Pro in an ADSB environment.
I will look to try it on SkyDemon + GeoRef of instrument plates/airport diagrams, @Dimme seems he just got one on SD? keen to see that tested…
Joke aside: very old but funny, from Avranches, ADS-B out on sheeps
https://www.info-pilote.fr/Experimentation-du-SCAS-a-l-aeroclub-d-Avranches_a1585.html
This will fit the bill for those flying/driving in Wales to have the SCAS (Sheep Collision Avoidance System)
Here’’s an airport diagram plate (note I’ve taken this grab from about 2500ft whilst on final approach at about 8nm). I haven’t got a screenshot, but the SD georef AIP plate comination is also good.
