Transponder not recognized

[RogerPotie 0]

I had a new strange problem today. Flying from Heatrow (EGLL) to Edimbourg RC4 repeately asked for transponder code 2632 (per example). But I was on that code. First I ignored it. But then I changed it and then put it back to 2632. Sitll the controller requested the code 2632. Every 1 or 2 minutes. No way to ask end of IFR. No menu showed that option. I had to stop RCV4 to get rid of the stubborn air controller.

[jd 57]

not sure how that could happen. the chances of picking two random codes, and they being the same is astronomicali'm wondering if you misheard the code? or maybe we have a 2.wav that says 6 or something like thatjd

[RogerPotie 0]

JD,I did NOT mishear the code. Or misread it on the message screen.This is the first (and hopefully the last) time I got this problem.

[Guest CowlFlapsOpen]

Roger, did you have the transponder on ALT intead of STBY? I've done that accidentally.

[RogerPotie 0]

Oh....I think I missed something somewhere.Flying the default Jetlear I only saw one place to enter any value to the transponder. I will check what you said next time I fly. Where and what should I search ?