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Pressure altitude to GTN

bnt83

Active Member
Is there an advantage to hooking up pressure altitude, such as the SSD120-30A-RS232, to the GTN-650?
 
Wow. Now that's a good question. Inquiring minds want to know. I myself am in the midst of hooking up a digital altitude source to a GTX 345. What about the GTN? What can that expensive wonder device do with serial or ethernet altitude input?

Jim
 
Wow. Now that's a good question. Inquiring minds want to know. I myself am in the midst of hooking up a digital altitude source to a GTX 345. What about the GTN? What can that expensive wonder device do with serial or ethernet altitude input?

Jim

A couple different spots in the GTN installation manual provide clues, they recommend connecting a pressure altitude source directly to the GTN, which can forward the information to the GTX-3X5 transponders assuming you plan on remote controlling them (both remote and panel mounted can do this). But it doesn't look like it can go the other way if hooked to the GTX and not the GTN.

I'm not sure if it enables more GTN features. I think its just supplementary data to help calculate GPS position.

I'm looking at a Transcal blind encoder SSD120-30N-RS232 which has two RS232 chanels and a parallel one. It will run parallel data to my super clock and RS232 to the other stuff for around $320.

I haven't decided yet if it should be hooked to both the GTN and GTX
 
Not sure but I think it can use that as part of its error checking functions when on a procedure and possibly also be used as an aiding input to the position solution. I think the different TSO levels may require/not require/use it differently.
 
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It helps provide accurate altitude information as a supplement to WAAS altitude.
 
Pressure altitude is also required for some procedures. The ones that say "climb to XXX before turning to 123". An IFR navigator can't give guidance on when to turn without the pressure altitude connection.
 
Pressure altitude is also required for some procedures. The ones that say "climb to XXX before turning to 123". An IFR navigator can't give guidance on when to turn without the pressure altitude connection.


I think in those cases that requires barro-corrected altitude which a blind encoder won't provide.
 
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