I agree with everyone that said wait until you are about 2 days away from your install date. Regs and equipment capability are changing all the time.
But I had a need to check the transponder and encoder output in my old airplane where I had an intermittent issue that the shops could not find. It ALWAYS worked when they had it.. I purchased on EBay a old devise that reads the output of your transponder via the radio waves it transmits. This requires that you need to have the transponder interrogated to see the output but with all the mode S systems around that should be no big deal. I am assuming you currently do NOT have an airplane set up for the transponder. This would mean you would need a test setup including power and interconnect between the transponder and encoder as well as an antenna (with ground plane). Then hang around a larger airport or perferabily one with an ATC radar and wait. Assuming you have the unit on sooner or later the unit will be interrogated and my little black box will show transponder output. Hook up a small suction devise to the static port connection on the encoder and draw a small vacuum and you can watch the altitude read out go up as well. I'll be happy to loan it to you if you pay shipping both ways. Come to think about it waiting until you actually are ready to install and having the entire unit Mode C certified (every two year requirement) for a small fee is sounding better and better. Just my 2 cents. As they say your mileage may vary. Gary Shubert Working hard to finish and fly my KR to Chino... I Hope ...... I Hope ...... I Hope ...... I Hope .....
