I wanted to thank the guys who have posted here. It helped me prepare for my Echo test flights.
It took me 3 test flights to dial my unit in and one call to Uavionix tech support. Lessons learned for me:
1) Follow the guidance int he manual, it's pretty good to a point. So in other words page 20-25 using the app and making sure the initial settings are in, and for me, page 34, because I'm using the simple "Legacy Transponder" setup and this page is the "application note" to set some of the remaining app settings.
2) The manual does not cover the "advanced setup" mode. More on this in a second.
3) Pull the airplane out of the hangar so the GPS can get a good lock and turn on the systems you have required to power up the Echo box (for me it's just my battery and avionics switch).
4) In your phone, make sure the wireless network "pingxxx" is chosen. No worries that your phone may show "! no internet" on the ping network. ADSB never gives internet, just ADSB, so that's by design.
5) Now open your Echo app that you downloaded previously, per the instructions on page 20.
6) You see "setup" and "monitor". Once your app connects to the Echo, you'll see some figures populate in the monitor page. Page 21-24 will walk you through some of the settings (and a visit to FAA.gov to look at your registration with your custom aircraft Mode S code). The displayed values (or not displayed as it was for me) that seem to be the types that may not populate in your "monitor" page, are the "Squawk" and "Altitude, Pressure". If these are blank, that means you have to change your transponder threshold. The only way into that setting is in your advanced configuration menu.
7) To get to the advances menu, go to "configuration". Then use 2 fingers to tap on the "echo" logo on the top of the page. Then scroll down and you'll now see input fields for transponder threshold. Don't change any of the other ones.
8) This setting starts at a higher value than would work for me. IOW, I had to lower mine to 1050 for the unit to work best. I lowered my setting 100 at a time until the transponder code showed along with the pressure altitude. Now, just because it shows does not mean it will pass a flight test yet. You'll notice you can adjust the settings and "send" the settings to the Echo. And there is a range where those settings will still show transponder codes and pressure altitude. But as said already, it's like tuning a FM radio with a dial. The settings along the high water mark and the low end, that display the code and altitude, are on the edge of working properly.
9) Bracket the values that work, and then pick a value in the middle. You can use numbers finer than 100 at this point. For example, 900 was too low - not showing values in the app. 1000 was ok on the low end, and 1125 was ok. But both of those values were the edges of the transponder reception by the Echo. when I'd change my transponder code to 1201, the app did not register it right away. At a range of 1025 to 1075, any code changes showed up right away in the app. I split the difference and used 1050 for my last flight, and then flew. Got a pass with all perfect scores at transponder threshold of 1050.
10) I flew two failed test flights early on not realizing the value of "fine ground tuning the system". And by the way, when I was ground tuning, I did not have my engine running yet. I was just using battery and avionics switch on. And no not for long, the exercise took about 3 minutes once I figured out how to "tune" the system quickly using the app. If it took longer I might have started up. Knowing what I know now I am sure I could tune one of these and probably pass on the first flight.
11) This is just my experience. There may in fact be far better ways to do it. I also want to thank David Wagner at Uavionix for talking me through some of this, especially the ground tuning trick.
12) Dave wants to remind everyone once you get a "pass" on your check (no red boxes) be sure to sign off your ADSB installation and also state the installation and test flight was IAW 91.225 and 91.227 and the date of the test pass. Print off the test pass and keep it in your records "just in case".
All the best guys, fly safe.