King transponder install question

JimWoo50 · #1 01-30-2012, 03:31 PM

I just received my King KT-76 transponder back from Flight Control Services after it was refurbished and approved for return to service. Encoder was also checked and okayed. I look at the wire harness and there are only three wires that do not hook into the encoder; red, white, and black. If I can figure out the proper connections for these wires can I legally install it myself? I'm thinking black is ground, red is power and white is ?.

Next question concerns the tray. What exactly is the purpose of the tray? Is it to hold the txpdr securely in the panel? I am looking at one on ebay for $75 and it appears that the antenna cable would not fit through the hole in the rear of the tray unless it unplugs from the unit. I am reluctant to pull too hard on it to see if it does. Does it indeed disconnect from the rear of the txpdr? Any advice would be appreciated. Jim.

Mel · #2 01-30-2012, 03:53 PM

Judging from your post, I strongly suggest that you have it installed by a professional!

JimWoo50 · #3 01-30-2012, 04:05 PM

Yeah I thought I would take a shot at it but I would probably end up causing more work for myself. Or ruining the transponder.

Walt · #4 01-30-2012, 05:49 PM

I agree with Mel.

I did a transponder check one time, the check itself took me about 15 min, then I went to go pull the unit out to get the serial number and I couldn't get the thing out no matter what I did. Well long story short the "builder" slid the unit into the tray and then screwed the backplate to the unit itself rather than to the rack. It also had screws going through the top of the tray into the top cover

It literally took me about 3 hours to get the unit out of the rack, then go find the hardware to correctly mount the backplate and connectors etc.. I was amazed the thing worked at all when I started pulling screws out of the top of the unit, it was a miracle it didn't go up in smoke.

aerhed · #5 01-30-2012, 06:30 PM

Score one for Walt. We used to hang that kind of item on the shame wall, but its become politycally incorrect to do that now.
For the OP, I'd look online or beg/buy a KT76 install manual and go through it. You will feel "schooled up". You might still want an installer afterward though.

JimWoo50 · #6 01-30-2012, 08:22 PM

Should I consider buying my own tray on ebay for $75.00 or is that something a installer will want to custom fit to my plane?

SteinAir · #7 01-30-2012, 09:09 PM

Quote:

Originally Posted by JimWoo50

Should I consider buying my own tray on ebay for $75.00 or is that something a installer will want to custom fit to my plane?

Others have put it fairly bluntly, so I'll follow.

With all due respect.....just STOP and sit back for a bit. Do you know if you even need a tray? Is there already one on your transponder? Do you have the plate on the back? Wires? Harness?

I'm truly not trying to be condescending, but you just don't know what you don't know. No harm in that as we've all been there, we're just trying to save you some heartache and money.

Cheers,
Stein.

JimWoo50 · #8 01-31-2012, 10:00 AM

you're right I don't know what I don't know. I was just somewhat anxious to install the newly oh'ed unit to see if it works before the 30 test period expires. But I can stop and take my time because I'm in phase one and the txpdr is not required where I'm at.