I took my wife up for her first flight in our new airplane and was unable to get flight following due to them not seeing my 'squawk'. Approach did work with me a little bit and said he had someone squawking 7777 in my reported area, turned off my KT-76 and he said the squawk went away.
Sounds like my transponder needs some magic mallet work. Are they expensive to repair or should i just opt for the Narco digital slide in replacment transponder? I believe the Narco AT-165/ka is the one I am talking about.
I had a KT76A that had been installed in 1978. It was working OK when I bought the plane 2 years ago, but then failed the 24 month transponder/encoder test. Paid $800 for a replacement cavity tube. Less than a year later, my son was flying the plane and ATC reported that they couldn't see his transponder. It was turned on but not operating. He turned it off and on, and it worked for 10 minutes and then shut down. I then decided to buy the Narco slide-in unit, which was $1500 from Aircraft Spruce. I wish I had done that first. I don't know what it would have cost to have the unit repaired, but it would still be a 30 year old unit.
HI DAV,
I just replaced a KT 76A the other day. The cavity was bad, $950.00 for repair only. I bought an exchange unit for $700.00. King is old but good radios I expect there won't be anymore problems for some time.
The KT 76 is about 30 years old. The 76A is still in production. Unfortunately it is not a slide in replacement.
I would not suggest a Narco. The field support is zero. I have had good luck with most of the Garmin transponders. The 320A is reasonably priced, and does not have the cavity tube issues the KT76A units do.
Assuming nothing has been changed with the antenna system since the original installation, I would suggest replacing the antenna and coax. A degraded antenna system can shorten the life of the transmitter conciderably. With a transponder that has a cavity tube, it will pull it off frequency and change the pulse width of the signal.
Before you do anything, have your 76 bench tested. I wouldn't spend a lot of time trying to fix it, but it may be something that could be repaired.
