Hello Jim,
The GTX 345 is the same
height and width as the GTX 327, but is 1.32" longer.
The GTX 345 should be able to use the same pressure altitude source that you are using with your existing Garmin transponder, but there is also an option for a built in pressure sensor that only requires you connect the static line to the back of the rack. When removing the GTX 345 from the rack, the pressure sensor remains on the back plate still connected to the static line.
The GTX 345 should also be able to use your existing transponder antenna. More information on antennas
in this posting. It is important to note that the GTX 345 can both transmit and receive ADS-B In/Out on the same antenna.
You may also order the GTX 345 with a built-in GPS receiver that only requires an external WAAS GPS antenna (supplied) to complete the installation and be an all-in-one ADS-B In/Out solution.
The compatible ADS-B traffic and weather display devices that will interface with the GTX 345 on both wired and wireless connections are described in
this posting and
this thread. Tablets and phones using Garmin Pilot or Foreflight and GNS/GTN units may also be used.
You are probably happy with your 496, but if you install a GTX 345, you will certainly want to consider taking advantage of the free traffic and weather it can provide, and now would be a good time to consider upgrading to an
Aera 660 with the
$100 holiday rebate in effect. Since the Aera 660 has two serial ports instead of the one your 496 has, you can easily connect the traffic/weather datalink to the GTX 345 while still performing all the other interface functions currently provided by your 496.
Every GTX 345 comes standard with built-in attitude sensors, which allows you to take full advantage of the 3D Vision page on the Aera 660 (shown below).
Let us know if you have additional questions. We appreciate this is a big decision and are happy to help any way we can.
Thanks,
Steve