Backup AI for all glass experimental

[rolivi]

I've purchased the Gemini ADI.

Now I'm going back and forth about wiring.

Option 1) Wire it to my GX-60 for GPS track input
Option 2) Don't wire the GPS and be in the habit of slewing it to known headings.

Option 1 makes sense, since it is the designed operational mode
Option 2 makes sense since it fits the usual ground mode, set the the DG that we learned for our PPL.

I've seen some posts about people in OPT2 mode, but they were 3+ years ago.

Any current thoughts are appreciated.

[Auburntsts]

I have the Gemini PFD as my backup. It's wired to my GTN 650. Not sure that really helps with your decision as I never even considered not wiring it to a GPS when I built my wiring harness and later installed it in the panel

[krw5927]

Originally Posted by rolivi

I've purchased the Gemini ADI.

Now I'm going back and forth about wiring.

Option 1) Wire it to my GX-60 for GPS track input
Option 2) Don't wire the GPS and be in the habit of slewing it to known headings.

Any current thoughts are appreciated.

Have the best of both worlds, and put the GPS serial line on a switch. Turn GPS aiding off if you want.

My guess is, after only a couple flights, that switch would stay on all the time.

[bwestfall]

Originally Posted by rolivi

I've purchased the Gemini ADI.... (snip)

Option 2) Don't wire the GPS and be in the habit of slewing it to known headings.

From a pros/cons list what advantages, if any, does this provide over the serial input from the GX-60? I'm not aware of any. I assume this is more of a "is it worth the work of breaking into the existing harness"?

I say wire it up to the GX-60

[rolivi]

I was thinking that my primary DG is from the magnetometer on the D-100, so wouldn't I want my backup to also be based on magnetic?

Then if I'm navigating on either of them the data is the same.

[TrutrakTech]

If it were me, I wouldn't want to ever look at an unslaved DG if I didn't have to. If the ADI is your standby/backup only, do you really care if your primary is magnetic based and your backup track based? In a failure situation, you'll have one or the other. If the GPS fails, you'll have an unslaved DG on the Gemini anyway.

Cliff's notes: I'd hook up the GPS to it

[MikeS]

Just my 2 cents. Since 2006 or so I've had the 3 inch version of the TruTrak ADI with GPS ground track and it's been a wonderful, reliable instrument for flying with reference only to instruments. I put it on a switchable secondary electrical system just in case primary system ever faiis however TruTrak sells a more elegant solution for that. The 3 inch version is now only available occasionally on eBay, usually about $600 when I've seen them. I bought my 3 incher from Gulf Coast and think I paid $1100. The 2 inch version which TT still sells is pretty pricey at $1300. Electronics generally go down in price over time, not up. Don't know what the story is with the 2 inch ADI that makes it an exception to this trend.

The Dynon D1/D2, BTW, is totally dependent on a GPS signal. Yes, it has MEMS and AHRS chips but for some perverse reason still requires a GPS signal in order to function. Lose your GPS signal for any reason and you've lost your attitude. The TruTrak ADI is a self-contained attitude instrument, using GPS only for ground track.

Although TT still has the ADI in the 2 inch format, I think it was a poor decision for them to do away with the larger version. I suppose it was to force customers to go to the Gemini if they want an attitude indicator larger than 2 inches. Having not looked into it I don't know this but I suspect the Gemini works the same as the ADI, but clutters up the screen with altitude and airspeed info - things we've always got with even the simplest GPS and altimeter. I love my 3 inch ADI with its straightforward display of just attitude and heading . . . and its instantaneous responsiveness. It suits my fingertip control aircraft perfectly when hand flying in the soup. I hope it continues to run forever.

[TrutrakTech]

Originally Posted by MikeS

Just my 2 cents. Since 2006 or so I've had the 3 inch version of the TruTrak ADI with GPS ground track and it's been a wonderful, reliable instrument for flying with reference only to instruments. I put it on a switchable secondary electrical system just in case primary system ever faiis however TruTrak sells a more elegant solution for that. The 3 inch version is now only available occasionally on eBay, usually about $600 when I've seen them. I bought my 3 incher from Gulf Coast and think I paid $1100. The 2 inch version which TT still sells is pretty pricey at $1300. Electronics generally go down in price over time, not up. Don't know what the story is with the 2 inch ADI that makes it an exception to this trend.

The Dynon D1/D2, BTW, is totally dependent on a GPS signal. Yes, it has MEMS and AHRS chips but for some perverse reason still requires a GPS signal in order to function. Lose your GPS signal for any reason and you've lost your attitude. The TruTrak ADI is a self-contained attitude instrument, using GPS only for ground track.

Although TT still has the ADI in the 2 inch format, I think it was a poor decision for them to do away with the larger version. I suppose it was to force customers to go to the Gemini if they want an attitude indicator larger than 2 inches. Having not looked into it I don't know this but I suspect the Gemini works the same as the ADI, but clutters up the screen with altitude and airspeed info - things we've always got with even the simplest GPS and altimeter. I love my 3 inch ADI with its straightforward display of just attitude and heading . . . and its instantaneous responsiveness. It suits my fingertip control aircraft perfectly when hand flying in the soup. I hope it continues to run forever.

Hi Mike, I'm happy to see if I can clear a little up for you.

We do offer two versions of the Gemini, the ADI and the PFD. The ADI is exactly what you're expecting; a glass version of our older mechanical ADI. No airspeed tape, no altitude tape, GPS used only for the ground track. The best part is, it's actually cheaper (as a new unit) than the ADI was when we still manufactured.

On the 2" ADI, think about a comparison with cell phones. Each year, the internal components get smaller and each version costs more than the last. It's the same thing here. It actually costs more to make it smaller.

The reason behind discontinuing the ADI 3 was due to the release of the Gemini. Glass is all the rage and it allows us to make the product lighter, thinner, and with zero moving parts.

I hope this helps a little!

[MikeS]

Thank you Lucas. Didn't now about the bare bones Gemini but then I haven't been paying attention. What I AM paying attention to is my position on the waiting list for that ECO. Please stop spending time on the forum responding to dodos like me and go light a fire under those vendors' rear ends that are holding up this project