[redwards]

I plan to install Skyview including Dynon's GPS module and Mode S transponder. Does anybody know whether this will legally meet the transponder requirement for airspaces like class B, class C etc. that currently require mode C? I do not plan to install a 430 or any other certified GPS. I sent this question directly to Dynon but received no response.

 

[Mel]

Dynon is using the Trig transponder.

Yes, the Trig transponder is TSOd and meets all requirements.

 

[DFlyer]

Randy,
We replied, but our email got rejected for some reason.

Yes, the Dynon Mode S transponder meets all current requirements.

In 2020 the FAA ABS-B mandate requires a certified GPS to be attached to it. It is a pretty good bet that there will be certified GPSs that are lower cost than the GNS430/530 by then.

In the meantime, our stance is that this is an exceptional transponder that is about the same price as just a Mode C transponder, so it is a good choice now and for the future.

One new detail; we recently found out that the FAA will probably require, in 2020, the higher power Class 1 transponders. This is so they can install fewer ground stations if everyone has the higher power units in their planes. So we now suggest that US customers purchase the higher power SV-XPNDR-261, instead of the lower power SV-XPNDR-262. Both are legal now, but the SV-XPNDR-262 may not be starting in 2020 in the US.

-Robert
Dynon Marketing

 

[Brantel]

Now that people are going to start putting high power xpders in smaller airplanes, it is going to reduce the accuracy of the distance info on most PCAS devices like the Zaon...

 

[Mark Burns]

I don't think so

Now that people are going to start putting high power xpders in smaller airplanes, it is going to reduce the accuracy of the distance info on most PCAS devices like the Zaon...

I don't think the power output plays a role in the distance info.
It's timing and the known speed of radio waves.

Mark

 

[Walt]

I don't think the power output plays a role in the distance info.
It's timing and the known speed of radio waves.

Mark

Hey Mark,
I don't think that's true, speed of reflected signals only applies to radar, transponders don't time anything they merely transmit data when interogated by a ground station or TCAS.

Zaon/PCAS devices do use power levels to estimate distance.

 

[Brantel]

Mark,

They sure do use power level. Take a look at the Zaon manual, it details exactly how they work for distance info.

The heavy iron birds are normally the only ones using the really high power xponders currently. I often see targets that are showing up close to me and when I find the bird it is way way way up there making a con trail... The big bird high power xponders confuse the Zaon into thinking they are closer than they really are due to the power output. The altitude is off as well but that is a different issue.

Also, if the target airplane has a weak xponder or a dirty antenna, it can show farther away than it really is.

I don't think the power output plays a role in the distance info.
It's timing and the known speed of radio waves.

Mark

 

[Walt]

Mark,

They sure do use power level. Take a look at the Zaon manual, it details exactly how they work for distance info.

The heavy iron birds are normally the only ones using these high power xponders currently. I often see targets that are showing up close to me and when I find the bird it is way way way up there making a con trail... The big bird high power xponders confuse the Zaon into thinking they are closer than they really are due to the power output. The altitude is off as well but that is a different issue.

Also, if the target airplane has a weak xponder or a dirty antenna, it can show farther away than it really is.

The -261 trig is a class 1A xpdr, the same as the garmin 320/327/330, all 125w minimum (avg pwr 200-250w).

There really are not many of the older 1B xprdrs around anymore that are low power (75w min). I also would not recommend the lower pwr trig -262 which falls into this catagory.

Max output power allowed is 500w which is usually the big boys.

 

[Brantel]

Good info Walt!

 

[Mark Burns]

Ok, I'd have never thought it

Mark,

They sure do use power level. Take a look at the Zaon manual, it details exactly how they work for distance info.

The heavy iron birds are normally the only ones using the really high power xponders currently. I often see targets that are showing up close to me and when I find the bird it is way way way up there making a con trail... The big bird high power xponders confuse the Zaon into thinking they are closer than they really are due to the power output. The altitude is off as well but that is a different issue.

Also, if the target airplane has a weak xponder or a dirty antenna, it can show farther away than it really is.

Ok guys, Thanks for the info.
I'd have never thought it would work that way.
The dirty antenna scenero was why I thought it couldn't be.

Walt, I didn't think it was reflected waves and timing like radar, but I did think it was somehow timing the interrogation and reply.

I'll bet someone will figure out a better way one day.

Mark

 

[Walt]

Ok guys, Thanks for the info.
I'd have never thought it would work that way.
The dirty antenna scenero was why I thought it couldn't be.

Walt, I didn't think it was reflected waves and timing like radar, but I did think it was somehow timing the interrogation and reply.

I'll bet someone will figure out a better way one day.

Mark

Thats one reason I perfer TIS over the PCAS devices, TIS give real data on range. The PCAS is dependant on lots of variable to approximate range info.

DME works by timing, you see where that's going... pretty soon radar will be a thing of the past when TIS-B is in place.

 

[ChiefPilot]

DME works by timing, you see where that's going... pretty soon radar will be a thing of the past when TIS-B is in place.

Really? I can't envision a post-9/11 ATC system that does not involve primary radar in one form or another.

 

[Walt]

Really? I can't envision a post-9/11 ATC system that does not involve primary radar in one form or another.

Well from that perspective you are certainly correct, radars role in the ATC system for traffic seperation will basically be replaced with ADS-B though.