In article 1131633301.948148@sj-nntpcache-3, Dave Butler
wrote:
For the kind of weather avoidance I need, I'm not convinced the differences
are
significant. I'm going to treat any kind of weather radar return pretty much
the
same, and assume there are errors in the presentation.

If you're going to do that, why even have weather uplink? It's only
good if you can trust it, at least to some level.



I have a 396, and I've taken a demo ride in an ADS-B equipped airplane. To my
eyes, the weather presentation is about equivalent. Maybe I'm not as
discriminating as you are. NCDOT is sponsoring some ADS-B equipped private
aircraft, and the price of admission is that you have to put on some seminars
and give people demonstration rides. Check the NCDOT web site for
announcements
of seminars and demos.

What are we comparing, NEXRAD? NEXRAD is only a fraction of the XM
weather products, and is often not the most useful in my experience.
I'm not sure what else ADS-B provides, but I suspect that it doesn't
provide as comprehensive a picture as the XM systems.



http://www.garmin.com/products/gdl90/

A GDL90 and an MX20 display is all you need. About $15K. Available today on
the
east coast. No subscription fees.

The receiver is $8,000 without installation. I'd have to pay $50/month
for more than 10 years just to break even on the receiver hardware
alone, excluding installation, and excluding the MX20 and GPS (doesn't
make sense to do one without the other). Doesn't seem like a good deal
to me if all I want is weather. For the record, it's more than the
GLD69 which, at $5,000 for the hardware, also isn't a great deal when
you can buy the GPSmap 396 for $2,500 and have a backup GPS to boot.




Mode-S TIS was a chimera. TIS-B (the traffic component of ADS-B) is available
wherever ADS-B is available. Nobody knows where that will be or what the
rollout
schedule will be.

Thanks for making my point for me regarding ADS-B.





JKG