My King KT76A transponder seems to be having some issues.
A couple flights ago, we were sitting at the hold short line to take off, and my instructor pointed out that it was not lighting up at all. I pressed the "ident" button and it lit up then. We made our flight and ATC did not report any issues.
The next weekend, I had my instructor fly the airplane to a neighboring airport to my new hanger last week, a five minute flight. Instructor reported no light on the transponder, ATC reported no transponder.
I called the local freelance avionics tech who recently did my two year recert on it. He said that the local radar station is famous for not always working very well and reporting transponder issues, and to take it up around the pattern again to make sure before I pull it.
I was working on my radios and intercom last week and the local AF base was active, and I noticed my transponder interrogation light was flashing a lot.
Yesterday I went to check it again. Sometimes it doesn't at all, but as long as you leave it on for 15 minutes, eventually the interrogation light will blink when you change codes, or move the selector from "on" to "alt" or vice versa. The test function always lights up. I was not being interrogated at all apparently. More concerning is that it makes a quiet, very high pitched whine when you turn the selector from "off" to any of the other positions. It's not in the intercom or radios.....it's a physical noise in the cockpit.
Anyone who works on these have any insight? Is this thing on it's way out? Can they generally be repaired for a decent price......or should I do like I did with my bad radio and just get an inexpensive used serviceable unit? If I do that, do I need to have an avionics shop program it to show my N number? Or how does that work? With ADS-B compliance looming, obviously I don't want to purchase a brand new Mode C transponder, and I can't afford to convert to ADS-B yet.
A couple flights ago, we were sitting at the hold short line to take off, and my instructor pointed out that it was not lighting up at all. I pressed the "ident" button and it lit up then. We made our flight and ATC did not report any issues.
The next weekend, I had my instructor fly the airplane to a neighboring airport to my new hanger last week, a five minute flight. Instructor reported no light on the transponder, ATC reported no transponder.
I called the local freelance avionics tech who recently did my two year recert on it. He said that the local radar station is famous for not always working very well and reporting transponder issues, and to take it up around the pattern again to make sure before I pull it.
I was working on my radios and intercom last week and the local AF base was active, and I noticed my transponder interrogation light was flashing a lot.
Yesterday I went to check it again. Sometimes it doesn't at all, but as long as you leave it on for 15 minutes, eventually the interrogation light will blink when you change codes, or move the selector from "on" to "alt" or vice versa. The test function always lights up. I was not being interrogated at all apparently. More concerning is that it makes a quiet, very high pitched whine when you turn the selector from "off" to any of the other positions. It's not in the intercom or radios.....it's a physical noise in the cockpit.
Anyone who works on these have any insight? Is this thing on it's way out? Can they generally be repaired for a decent price......or should I do like I did with my bad radio and just get an inexpensive used serviceable unit? If I do that, do I need to have an avionics shop program it to show my N number? Or how does that work? With ADS-B compliance looming, obviously I don't want to purchase a brand new Mode C transponder, and I can't afford to convert to ADS-B yet.
