DME recommendations

Here's where I'm at now.
I was interested in checking out IFR GPS units as a DME alternative.
You can get an older (KLN 89/B) unit pretty inexpensively.
So I went to my local avionics guy and talked to him a bit.
After explaining what I wanted to do, he actually recommended going the DME
route.

For an older GPS, I'd have to get another indicator to slave to it.
He also said installation costs would go up as a result.

He said the best solution (cost/complexity-wise) would be to pull my ADF and
put in a DME.
If the avionics guy is telling me this is lower cost/complexity, I guess I
better think about it!

So now I'm thinking of two choices.

1. Find an inexpensive DME. I'm thinking either Narco 890 or King 62/64.
Definitely not a remote unit.
2. Find an inexpensive IFR GPS with built in CDI (kind of like a King KX-125
NAV).

If anyone knows of such a GPS, I'd appreciate it.
If anyone knows a source of great used avionics, I'd appreciate that, too.

Oh yeah. One other alternative I was thinking of was using a KLN 89/B for
enroute only, no approach.
That is, using the GPS sort of like a DME.
Is this legal? Can you do this? The only reason I ask is that I can find a
KLN 89/B for less than a DME 64.

Thanks,

Adam
N7966L
Beech Super III

mindenpilot wrote:
: 1. Find an inexpensive DME. I'm thinking either Narco 890 or King 62/64.
: Definitely not a remote unit.
: 2. Find an inexpensive IFR GPS with built in CDI (kind of like a King KX-125
: NAV).

: If anyone knows of such a GPS, I'd appreciate it.
: If anyone knows a source of great used avionics, I'd appreciate that, too.

: Oh yeah. One other alternative I was thinking of was using a KLN 89/B for
: enroute only, no approach.
: That is, using the GPS sort of like a DME.
: Is this legal? Can you do this? The only reason I ask is that I can find a
: KLN 89/B for less than a DME 64.

AFAIK, you can only legally use the distance information in an IFR GPS if it's
actually IFR certified. That means that you need all the bells and whistles and an
actual IFR cert. In other words, if it's old enough to be inexpensive, it also needs
a dedicated CDI to go along with it. If you install an older IFR GPS as VFR-only, you
can't legally use its distance info as a substitute for ADF/DME.

As far as the DME goes, some of the units get their channeling from another
NAV, and some can chose between that and dial-themselves. Wiring up the channeling to
another nav will cost some labor on the install, as it's tedious and has to break into
existing wiring.

If you have the panel space and/or desire to go with the KNS-80, you get lots
of functionality for the same or less than the DME only. Be aware, however, that it
takes CDI head that doesn't have a NAV converter built-in, but sends out the OBS
encoder to the unit. They're less common, and useful with IFR GPS installs, so they
can be hard to come by. Lots of people have upgraded their KNS-80 to IFR GPS and kept
the NAV head. Technically speaking, you could install the KNS-80 without an indicator
and just use it as a slightly heavy, tall DME (or even a DME to an RNAV point, come to
think of it... maybe even an ILS with a converter-head).

-Cory

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* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
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