You will probably never have trouble getting King updates.
There are TONS of KLN89's out there. Quite a few 90's also.
Garmin will probably continue to support the 155 as they are going
great guns and will support all their products as they have the money
and protect their reputation.

"C Kingsbury" wrote in message link.net...
Hi all,

Currently examining options for upgrading a 1979 172N with an IFR-certified
GPS. We currently have two good nav/coms, M-1 Loran, and ADF that we want to
replace.

Goal is to find the most cost-efficient IFR GPS install to replace the ADF
and add legal /G and DME capabilities. Keeping in mind that the plane is
worth maybe 50k we are not going to spend 10-12k on a GNS-430 class box, so
as I see it we have these options:

- Northstar M-3 Approach
- Garmin 155 or 155XL
- King KLN-89B or KLN-90B
- Apollo GX-50

AFAICT one can pick up a decent used example of any of these for between
$1500 and $3000 depending. I know we'll also need the annunciator and CDI,
and that installation/certification will comprise 50% of the total cost.

One of my big concerns in buying an older GPS is database updates. I want to
make sure we will not end up say a year or two down the road with an
expensive VFR GPS because updates are no longer available. Also, general
mfr. support.

I would like a decent moving-map capability, but given that we have none in
the plane right now, even a simple airspace depiction like the KLN-89B would
be a significant gain. If we want something snazzy we can get it better on a
handheld anyway. I would spend an extra $500 for a better map, but $1000 or
$1500 I'd wonder about.

What would you guys do?

Best,
-cwk.