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Old September 2nd 03, 07:43 AM
Mark Mallory
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Wayne wrote:

Anyone have one of these?


I have one in my '182. Works OK.


Mine was inop when I got the plane and I now
have it operating (well, at least lighting up) and don't have an operators
manual.


What did you do to make it work?


I tuned in the ILS freq and don't get any distance.


Most ILSs don't have DME. Not all VORs have DME. Try a frequency that you are
reasonably certain has a valid DME signal (VORTAC, VOR-DME, ect.) Check the
A/FD or other reliable reference for your area.


If I pull the
knob, I get an "RMT error".


This means you don't have a valid remote channeling input to the unit. My unit
is wired to my #1 NavCom; the DME tunes the #1 Nav frequency when the knob is
pulled. If I switch the #1 NavCom off, I get the "RMT error" message on the DME.


I have not been in the air yet with the unit, it
may be just not working in the hangar with the door open, however, my other
2 nav radios are able to tune and ident the ILS and the VOR a few miles
away.


DME operates at a frequency approximately 9 times higher than VOR/LOC. You're
not likely to receive anything unless you have a good "line-of-sight" path to
the station, or unless you're on the ground close to it (the VOR-DME at my
airport is on top of a 100 foot tall building less than a mile away, and I'm
barely to receive it in my hangar.)

My experience with my '890 is that even in flight and within line of sight of
the station, it will often not indicate even though the co-located VOR has a
strong signal. This behavior is not consistent, however. The unit has worked
soldily 70 or more miles from a station (with a scratchy VOR signal), and has
been intermittent or dead at less than 15 miles (with a strong VOR signal).

It's possible for signals from your transponder to interfere with your DME (they
operate at close to the same frequency.) Some transponders have a
"pulse-suppression" input to allow the DME to inhibit transponder reply pulses
during the time the DME is receiving. It may help to *momentarily* switch the
transponder to stby if the DME has trouble "locking" to a signal.