The King KN62/63/64 units are probably the most reliable bit of GA kit I have seen over the last thirty years with the display being the only weak spot.
Problems (apart from the display issue ) are usually connector or cable issues, I would guess the units hit the market in about 1980 so some of these units are using forty year old wires to function and have lived in very hot radio stacks because the owners would not pay the extra few quid to fit an avionic fan.
Peter wrote:
You mean the KDI572?
No I mean the display on the KN64, which is a normal flatpack integrated unit, not the remote variant.
Turned out it didn’t
That is quite normal. I bought some box the other day and offered him ~ 50% and said half the stuff for sale on US Ebay is dud.
the display was still a problem
You mean the KDI572? See threads here on repairing these 
If you buy a few of them on US Ebay, duds, for almost nothing, you will get enough parts to repair yours. That is all that outfits like Straubing do, because the controller chip and the display are no longer available, and they have an “EASA licensed laser printer” for the paperwork
The DME situation is a mess. I bought a secondhand KN64 in January 2023 from a fellow Socata guy in the US who guaranteed it worked. Turned out it didn’t, and Straubing wanted €1600 to fix it after agreeing to evaluate it for €100. When I declined their offer, they wanted the full amount because they’d already started repairing it and it was now working. After wrangling we settled on about 700 to return the unit to me.
When I got it back the display was still a problem. After 9 months with the problem I sent it to SEAM in France for an OH exchange for about 2k. I’m now 4k into this project mind you. After installation of the OH unit it worked for 20 mins or so then stopped. This happened on several flights—probably overheating. Sent it back to SEAM who bench tested it and found no issues. Again wrangling, and they agreed to replace it with another OH unit. That’s where it is now, 1.5 years later. €4k, 1.5 years, and still no working DME.
I wonder whether an easier way to make money would be a pin compatible version of the KDI572. The data interface is very simple, is documented, and has been emulated by the Sandel SN3500 which can also display the DME value. It would take a competent hardware/software guy only a month or so to get it working and then it needs to be packaged into the same size box. Much much less work than designing a DME.
PMA would be the obvious route but is rare for avionics if you want to PMA somebody else’s product. The display would look different, for a start (dot matrix LED, probably). So it would need to be an STC.
And the market is shrinking… the time to do this would have been 10+ years ago.
Bathman
You are correct, the display is the week spot of what is otherwise a very reliable unit, I don’t have this problem as I use the KN63 remote unit that displays on the Garmin PFD.
So is there any truth in garmin introducing a DME unit?
I know A&C commented on the King units being good units but they are now getting a bit long in the tooth especially with respect to their displays.
GPS is a problem. From browsing through the official strategy document (for Norway), there are two main issues for civilian aviation.
The solution is to keep traditional navigation systems as fully functional “backup” as long as they last and it’s an economical option. By the looks of it (from Avinor visual approach carts) this results in more DMEs and less NDBs and VORs.
The main direction is still GPS though. But there are other stuff going on also. Last year Avinor finished their network with over 200 WAM stations. It’s normal operational mode is with GPS (standalone or with ADS-B), but it will also operate without any GPS. WAM needs very precise timing, which is cheap and easy to get with GPS. Without GPS, atomic clocks are needed, which is being installed now. WAM/ADS-B is not a navigational system, but with ADS-B-in it certainly could be used as such for GA also without GPS. As a GA pilot today, with an old mode C transponder, I’m only a radio call away to know my exact position, even without radar or GPS.
However, googling this stuff I found another slightly disconcerting thing. In Norway there has never been any focus on mode-S. For GA transponder is optional, but mode C is required in controlled airspace wherever/whenever ATC say it is. The aviation authorities together with Avinor and the met office has plans to make ADS-B mandatory in all controlled airspace from 2030 already. The disconcerting part is that the GA community as a whole would welcome this, due to all the upsides as online weather and a standard traffic information system system for everyone (not the jungle it is today). This will also include drones. There will be close to zero opposition to it, and therefore it will be implemented.
Any future DME would have to offer more than simple distance to a station. In an ideal world it would be a unit capable of simultaneously accessing two or more DME stations, to make this a flexible navigation system the unit would require a database.
It follows that the DME should be able to access the GPS database and present position data using the equipment currently presenting the GPS information. This will not be a panel mount unit but one that will be remote mounted and controlled via software presented on the GPS or the ND. It would also have a lock function for use during approach .
It would be my guess that the reason we have yet to see a DME from Garmin is the KN 62/63/64 range (& KR87 ADF ) had been developed by Gary Burrell before he left King avionics to set up Garmin and he saw little advantage in duplicating what is a very reliable unit…… so he just made sure that Garmin Avionics were compatible with the King DME & ADF.
As GPS jamming and spoofing are now real dangers the market needs a reliable alternative navigation system be that DME or eLORAN.
Peter wrote:
In fact you need only 1 DME to get position!How does that work?
How does that work if you fly an arc around the DME?
