Narco 890 DME

[Htmlkid]

I have two of these I have swiped in and out of my aircraft and both display the frequency but will not display distance. Im assuming there is probably something wrong with the antenna,,,, thoughts?

[Prior owner]

That would be a logical place to start troubleshooting… undo the screws from the belly panel and make sure that the antenna connector is securely attached to the antenna. Check also the antenna connection at the back of the unit. Sometimes people don’t connect the BNC connector at the antenna while re-installing the belly panel. Clean the outside of the antenna, and the inside of the socket with contact cleaner, while you have it open.

do you have line of sight with a DME facility ?

Has the DME ever worked properly in your plane?

[47U]

2 hours ago, Htmlkid said:

both display the frequency but will not display distance.

I think PilotCoyote is on the right track… you have a lack of signal issue.  

Besides the distance not displayed, you’re also missing the groundspeed and time to station as well?  The displays will go bad in time, but for both of your units to fail the same would be a long shot.  

Is the wire to the audio panel in place so you can listen to the station identifier?

While you’re inspecting the condition of the BNC connectors, what condition is the coax?   

[carusoam]

If you meant Narco…

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