alpinelakespilot2000

Well Known Member
I'm planning on a transponder test in the next couple days, but am not sure if the test shop will know how to test my setup. I have a Dynon D180, Garmin GTX 320A, and the converter module from Dynon.

I have already set up the Dynon letting it know I'm using the converter module. Other than turning on the D180 and transponder at the same time, will I need to instruct the avionics shop to do anything else? (It's a small airport with not a lot of experimental activity, so I'd hate to pay them $100 to tell me my transponder/encoder is not working when it's really just them not knowing how to test it.)

Thanks.
 
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as long as you've wired it up correctly, a transponder test is no different for homebuilt or certified aircraft.
 
You just need to let them know where the altitude data is coming from. Some shops that don't deal with experimentals may give you a hard time with the data coming from a non TSO'd unit, but it's legal.
 
I just had this exact set up tested on Thursday. Not a problem at all.
Thanks Kelly. Am I correct that the only setting that needs to be adjusted in the D180 is to select "Format 1" under the "ALTENC" menu. Then, assuming I've wired correctly, the D180 and 320A will be communicating fully once they're both turned on?
 
Yep,

If you have it wired properly and it is getting power and you have the D180 configured for Format 1, it will be seamless to the guy doing the test.

The D180 will spit out whatever altitude the D180 displays when the altimeter is set to 29.92. The converter will convert that to Grey Code and that is what your xponder understands.

When they do your check, they will move the altitude up and down to test the altimeter and to test that your xponder is getting the correct altitude information from your encoder. If you have any of the wires switched around, this will become apparent during the test.

It really is a painless process if you have all the wires correct and the correct format setting in the Dynon.
 
Just did this

Just did this last weekend with D-100 and GTX-327, no problems and the 327 display was within 10ft of the fancy test box. I did do one dumb thing though which was only turning on the transponder!! Forgot to turn on the D-100 which powers the encoder, caused a few head scratches for about 30 secs:eek:
 
No encoder

Just did this last weekend with D-100 and GTX-327, no problems and the 327 display was within 10ft of the fancy test box. I did do one dumb thing though which was only turning on the transponder!! Forgot to turn on the D-100 which powers the encoder, caused a few head scratches for about 30 secs:eek:

I has been a few months and I am in Japan and can't look at my manual but I thought with the D180 and the GTX-327 you did not need an encoder. I am about to rivet on my top skin soon and if I need to wire in something extra I better do it before hand. I have not flown yet only tested after the wiring was complete, no transponder (offical) test done but as I recall my transponder was getting altitude info from the D-180
So do I need another piece of equipment or is the enchoder you are talking about built into the D180.

Thanks, killing time on VAF before flying back home.

Cheers
 
Mike,

The D180 is the encoder. The 327 does not need anything but the D180 because it accepts the native serial encoder output of the D180.

The original poster had a 320A which needs the serial to grey code converter since it does not accept the serial data.

You can use the converter with the 327 as well but it is not required.
 
Hew

Mike,

The D180 is the encoder. The 327 does not need anything but the D180 because it accepts the native serial encoder output of the D180.

The original poster had a 320A which needs the serial to grey code converter since it does not accept the serial data.

You can use the converter with the 327 as well but it is not required.

Thanks, I was convincing myself that i must have done something wrong. Funny what you forget after a few months.

Cheers