JPI EDM 790 Upgrade - Anyone done it?

[mshac]

So you can do a "plug and play" upgrade on your EDM 760 with the EDM 790. They claim you just unplug the 760 and plug in the 790. The 790 offers a much larger color LCD screen, where you can see more data without having to push buttons.

Total cost $1500 + $300 "core charge" which is refundable if you send in your 760.

So that leads to my question - WILL IT FIT? You have to specify if you want it offset to the left or the right (Odd that there is no "centered" option).

I was gonna put it on the bottom of the three vertical instrument locations to the right of the six-pack, since that's where my 760 lives. It looks awfully tight to me, and I just don't know if it will fit down there. I attached a pic showing where I mean.

Any experience with this?

PS - Pay the $300 core charge, because you can sell your 760 for at least twice that on Ebay. A couple sold recently for right around $1000 each. That would make the net cost of the upgrade under 1 AMU!

[Dr.Dan]

I have the 790 and I like it.
I do not think it will fit in the spot you're proposing. It is much larger than a regular round gauge. Mine is at the top of the center stack.

DD

[mshac]

Thanks Dan, I was afraid of that. Seems like a great deal though for someone with the room to install it!

I called JPI and they will sell me plug-in wiring harness extensions that would allow me to relocate the instrument. Sounds a lot better than try to splice extensions yourself.

Here's a pic of my full panel. I honestly don't know if I have a place for it! Please feel free to suggest where it might be able to fit.

http://www.337skymaster.com/messages...7&d=1598915816

[wslade2]

Ditto. I also have 790. I thought I could slide it in in a mirror position of your 760 on the copilot side, bottom left where there was a second altimeter. But when it arrived, screen to big. Likewise I ended up putting it in center stack lowest position. Your location too tight for the offset screen.

You could move your OAT and put it there. Or use the 790 to replace the OAT; it has an OAT function

[mshac]

Originally Posted by wslade2

Ditto. I also have 790. I thought I could slide it in in a mirror position of your 760 on the copilot side, bottom left where there was a second altimeter. But when it arrived, screen to big. Likewise I ended up putting it in center stack lowest position. Your location too tight for the offset screen.

You could move your OAT and put it there. Or use the 790 to replace the OAT; it has an OAT function

That's not a bad suggestion. Not an ideal sight line, but the original OAT gauge hasn't been super reliable, and if the EDM has an OAT, then that would be a good replacement. I don't currently have OAT on my 760, maybe its not enabled?

So then what to put into the empty hole where the 760 was? A G5 maybe?

[Multimotor]

Beautiful panel.

Can you move your autopilot control to the current 760 spot? It would help if it could be surface mounted, but it looks like there is an adapter plate there, anyway. That'll give you plenty of room if you're going to abandon your current OAT gauge. OAT is an option in the 760/790. My transponder has OAT, so I saved $195 by not ordering it for the 790.

That's still not the ideal position, but your choices are limited. I don't think enlarging the OAT hole will help.

At any rate, I recommend you look at the installation manual and make a template before committing. The case can be mounted upside down, depending on how you want the offset, then the display can be rotated with some button pushing.

[mshac]

Originally Posted by Multimotor

Beautiful panel.

Can you move your autopilot control to the current 760 spot? It would help if it could be surface mounted, but it looks like there is an adapter plate there, anyway. That'll give you plenty of room if you're going to abandon your current OAT gauge. OAT is an option in the 760/790. My transponder has OAT, so I saved $195 by not ordering it for the 790.

That's still not the ideal position, but your choices are limited. I don't think enlarging the OAT hole will help.

At any rate, I recommend you look at the installation manual and make a template before committing. The case can be mounted upside down, depending on how you want the offset, then the display can be rotated with some button pushing.

Thanks, I really like this idea. Not sure what the costs would be to move the STEC 60-2 control head, but I scan that frequently to be certain I'm the correct AP mode (Heading, NAV, VS, Soft Capture, ALT, Approach, Ready, etc) so it being closer to the six-pack makes sense. I'll get a template made and see if the EDM 790 fits where the OAT & AP head were. I'm pretty sure it will.

Again, thanks for the great idea!

[Multimotor]

You're welcome.

BTW, my checkout instructor recommended that I move the cowl flap switches back to neutral after use, just in case a motor keeps running.

[kbecker]

I learned this cowl flap lesson the hard way by burning out my front cowl flap motor years ago because one of the limit switches was mis-adjusted.

[mshac]

Originally Posted by Multimotor

You're welcome.

BTW, my checkout instructor recommended that I move the cowl flap switches back to neutral after use, just in case a motor keeps running.

Thanks, I'll have to add that to my homebrew checklist! Maybe even add a small placard "Return Cowl Flap Switches to Neutral". Perfect area right above the switches.

I do check the operation of the cowl flap motors on a regular basis, but you never know when a switch may come out of alignment or just plain fail. Had to throw away a favorite keyboard recently because a couple keys weren't working. Switches don't last forever!

[CRDedrickson]

I upgraded from the EDM760 to the EDM790 last year and it was a great improvement. I delayed a while because I ended up redesigning the panel for avionics and the 760 was too close to the Shadin to accommodate the front display until the redesign.

I mentioned the Shadin. Prior to the upgrade, I consulted with Shadin and JPI and asked if I could jumper from the Shadin fuel flow to the EDM. Both said it was doable, and I’m glad I did. Later the Shadin went INOP, but I still have FF (from the same sensors) on the 790. There is an additional benefit in that the EDM keeps track of flow from each sensor, whereas the Shadin doesn’t. The Shadin adds flows together for total remaining (probably someone postulated swapping tanks and ‘fooling’ the total… bad move in my opinion). Anyway, the additional benefit of fuel flow on the 790 is that you can download the data with the same timeline as all the other measurements. This makes leaning response a lot easier to review.

My original 760 did not have fuel flow. But when I ordered the 790 I had it included. I bought a working 760 on EBay that did have FF, but ended up trading in the original 760 w/o FF. They didn’t care, so I kept the 760 with FF as a potential backup. But the 790 is so much easier to read and download from that I’d never swap it out!

I just saw your post tonight and so hope this helps anyway. I was looking for FUEL GAUGE upgrade options, which so far on this site have eluded me!

Russ N8CV, 1973 T337-G P0056 (pressurized)