Sky echo 2, transponders, Hex code, AvPlan….

[Mike Gearon]

Avplan problems

 

AvPlan used to display in Pipistrel 23-1750 twice. Must up to date I assume coming from my own and other aircraft ADSB out. Second slightly behind the pace from Avplan and only available while cellular service works.

 

Avplan stopped display and I only just worked out why. 4 devices were logged on. 3 is max. Avplan doesn’t tell you it won’t work and why. It really should have a warning or I didn’t see it. Anyway, solved. It works now. It just displays a wrong aircraft as below 2 days ago or doesn’t display one at all as now and I have no idea why. iPad displayed the aircraft below 2 days ago and iPhone doesn’t show one at all. 

 

Transponder.

 

I suspect it’s somehow lost the hex code. Happened after a complete Garmin downgrade and upgrade as per AD but I can’t see how that stopped  the transponder sending.

 

I’ve applied to casa for either the existing code or a new one with no response yet. Maybe a holiday backlog. See pic below of the Sinus I had reg in USA. They all have a hex code. No applying. It’s just there. Why don’t we have this? Too simple?

 

 

[kgwilson]

Have you set the "Ownship" filter to "On" in your SE2. If it is not set and you have Mode S out or SE2 set to transmit out it can cause a ghost image of your aircraft on your nav device.

[Mike Gearon]

9 hours ago, kgwilson said:

Have you set the "Ownship" filter to "On" in your SE2. If it is not set and you have Mode S out or SE2 set to transmit out it can cause a ghost image of your aircraft on your nav device.

Sorry, I’d meant to mention the SE2. I’ve just purchased for the motor glider and if I understand the instructions correctly it still needs a hex code from CASA. 
 

I figured I better sort the Pipistrel out and  make sure it is sending ADSB out from transponder before I bring something new to the mix. I’m going to call my avionics guy tomorrow and have  him sort. Mechanical I’m good. Electronics amd communications not so much. That’s why we have RFguy and Kyle com.

Edited January 21, 2023 by Mike Gearon

[Old Koreelah]

Maybe a silly question, but does anyone know if the transmissions from the SkyEcho2 are directional?

I have nowhere on my panel to put this little unit, so intend to mount it on the side, near my shoulder. 
That means it’s side-on to oncoming traffic. Is that an issue?
 

[kgwilson]

The antenna is omnidirectional but the signal is line of sight so it needs a clear view forwards & sideways to provide good coverage & also needs a clear view of the sky for the GPS. 

Exerpt from the manual below.

 

7.1 Installation
SkyEcho is a completely self-contained portable device with no required installation for external antenna, power source, or physical installation into the aircraft.
Transmission and reception performance are affected by antenna placement within the aircraft and is subject to airframe shadowing. Best performance is achieved when the SkyEcho is placed vertically orientated on the aircraft window mounted with the suction cup mount in a forward or side facing window with clear line of sight visibility in the direction of travel and clear visibility to the sky for GPS reception.
 

[Kyle Communications]

52 minutes ago, Old Koreelah said:

Maybe a silly question, but does anyone know if the transmissions from the SkyEcho2 are directional?

I have nowhere on my panel to put this little unit, so intend to mount it on the side, near my shoulder. 
That means it’s side-on to oncoming traffic. Is that an issue?
 

The smaller pcb track lines are the 1090 mhz for the ADSB..it is on the right side. Ideally you should have it on the windscreen facing forward but it depends of course what direction oncoming traffic is coming. So its much of a muchness. The main thing is to make sure it has clear view of the sky for the GPS signal and no obstructions..metal of course in its way

 

[Old Koreelah]

Don’t trust suction cups, especially on curved windows. I can screw its twist-on mount to the plywood just under my RHS window, near my shoulder. This gives a good view of sky above. I presume signals aren’t much affected by acrylic canopy, polycarbonate screen and plywood fuselage?

[RFguy]

they're a little directional, but up to 10nm shouldnt matter too much. not affected reliably measurably by poly screen plywood etc. and not even metal struts and thin members, since the RF tends to re radiate off those items.

[Old Koreelah]

Can’t do much about the engine, which, I presume, also cuts the “view” of my radio aerial.

[RFguy]

not really. unless was mounted where it was heavily shielded/ obstructed- IE say, on the back of the stator.

If the skyecho is mounted at least the distance behind the engine of the maximum dimension of the engine, it wont have much effect. 

[Old Koreelah]

I guess the best way to find out is try it. Next time our club has people flying about, make a few test-transmissions to aircraft directly ahead, at distance,and get their feedback.

Thanks for the helpful advice.

[RFguy]

experimenting with another (airborne) aircraft will simply multiply the two uncertainties from the two aircraft. You'd be better to park the 2nd aircraft , or set up the SkyEcho on a tripod, with tablet sitting on a seat underneath, and fly the 1st plane (device under test) in some direction  (get some altitude to maintain line of site )  and once on station 10 to 15nm, where the pickups are becoming marginal, execute a shallow 15 deg max turn  360 deg and note the pickup variation with test aircraft heading. repeat 3 times to generate trend. Rotate test receiver 90 or 180 deg and do it again.

Edited April 10, 2023 by RFguy

[Old Koreelah]

That sounds like a pretty complex way to test if it works. Surely it’s much easier and more intructive to use real-world testing?

[kgwilson]

I just stuck mine on the LH side of my bubble canopy just in front of me & I get coverage from about 0 to 140 deg to the right and about 190 to 360 deg to the left so only about 50 deg that it can't see. 

 

It's easy to test. If an ADSB out equipped aircaft comes in to view on the left just make a shallow RH turn till it disappears & do the same in reverse if one appears on the right. A lot of the GA training aircraft around here have ADSB out installed with their Mode S ES transponder so I see them around all the time.

Edited April 11, 2023 by kgwilson

[RFguy]

@O-K - that is real world testing with reduced  ambiguities....

 

What you first described was essentially random point testing. The result will essentially be meaningless. You need alot of testing to get data you could talk about. probably 100x the data ,  compared with my method which seeks to reduce the uncertainty .  You cant get signal strength from the system so you'll need to move the system performance intoa region where you can measure signal strength by means of works OR does not work.  That's the reason to get distance. Once you are at distance , say > 13nm,  you can fly in a circle around a point on the ground without changing the range more than 10%. By flying circles you can map the directivity of your airplane / skyecho combination.  Then by doing some rotation of the fixed device at the 'base' you can assess the degree of directivity by the device without the airplane around it...  AFter rotating the fixed device, you might need to go further away or come closer  to get on the threshold again.... Well there are other ways, but that's how I'd do it with a pair of Skyechos and nothing else. 

Now if I were doing it, I'd get the plane to go out into the apron, and set up my test gear , and just read the signal coming back from the airplane as it was rotated 360deg like a compass swing test..... You can do this with a $30 ebay RTL-SDR receiver and a laptop...



 

[kgwilson]

It isn't meaningless to me. I don't care about range so long as I can see anything in my vicinity and whether we are likely to be in conflict.

[bushcaddy105]

It's easy enough to make an acrylic right angle bracket with the suction cup on the base and the SkyEcho on the vertical. It will then ideally meet the recommended mounting position when on top of the panel looking forward. To make sure the suction cup stays stuck I smeared mine with silicone adhesive/sealant before mounting. I don't remove it from the aircraft as its power is supplied from a 2 amp USB outlet behind the panel. 

I'll take pics on Friday when at the hangar, and post on Friday night.

[Old Koreelah]

I intend to remove the suction cup and mount the twist-on mount directly.
Had too many suction cups lose their grip.

[kgwilson]

The suction cup is fine so long as there is not much if any curvature of the acrylic surface and the acrylic has no scratches on the mounting location. The cup must be kept very clean but never moistened. Mine has never fallen off.

[bushcaddy105]

47 minutes ago, kgwilson said:

The suction cup is fine so long as there is not much if any curvature of the acrylic surface and the acrylic has no scratches on the mounting location. The cup must be kept very clean but never moistened. Mine has never fallen off

The suction cup wouldn't hold for long on the slightly curved and painted alloy deck above the panel, hence the adhesive. 

[RFguy]

Suction cup seems to work fine in the Jabiru  and covers a day or few. 
As for range measurement : Yeah, my seemingly laborious proceedure to measure Skyecho range - well, you guys know what I do for a living, I have to put my c0ck on the block , and I need to be able to stand behind my numbers... hence the methodology. One man's overkill is another man's freedom from court challenge.

[Blueadventures]

1 hour ago, RFguy said:

Suction cup seems to work fine in the Jabiru  and covers a day or few. 
As for range measurement : Yeah, my seemingly laborious proceedure to measure Skyecho range - well, you guys know what I do for a living, I have to put my c0ck on the block , and I need to be able to stand behind my numbers... hence the methodology. One man's overkill is another man's freedom from court challenge.

All good, no worries, appreciate the detail and I take out what I can understand. Cheers and keep the info coming. 

[bushcaddy105]

On 12/04/2023 at 7:49 PM, bushcaddy105 said:

It's easy enough to make an acrylic right angle bracket with the suction cup on the base and the SkyEcho on the vertical. It will then ideally meet the recommended mounting position when on top of the panel looking forward. To make sure the suction cup stays stuck I smeared mine with silicone adhesive/sealant before mounting. I don't remove it from the aircraft as its power is supplied from a 2 amp USB outlet behind the panel. 

I'll take pics on Friday when at the hangar, and post on Friday night.