encoder question

[DKirkpatrick]

Bought a Garmin GTX 330ES for ads-b compliance in my Cessna 172D. So... does that get it? Or, is an encoder required? And if so, which one, or which spec is required? I've got one on a shelf that was in use with an Apollo S70 transponder.

It's a 14VDC airplane, and trying to get it IFR certified.

Coaching would be MUCH appreciated.
thanks,
dan

 

[asicer]

is an encoder required?

Yes. But is this new transponder replacing an older one? If so, you might be able to re-use the encoder that the older one used.

 

[Jesse Saint]

As long as you have an approved WAAS position source, that should be good. Whatever encoder you used before should work fine for the 330ES.

 

[DKirkpatrick]

thanks for the help Jesse! much obliged.

 

[Gary Ward]

My original encoder was a good sized aluminum box. My avionics shop said with my particular panel in my 172 that it was too big and old to reuse.