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Transponder woes: ID button missing

Some may remember my thread on the earlier forum. I got the transponder out of the plane today, and understand the problem better: if I cannot ident, it is for lack of an "ident" button ! That is to say, the switch is there all right, but lacking is some kind of butto that must go through a hole in the front panel. So that, where the panel says "ident" there is only a hole of perhaps 1/8".

I would acquire the missing button as a spare part but am afraid it would be both rare and expensive. Alternatively, I could get a friend to produce one on a lathe, from brass or even from nylon. But what should it look like?

The all important point: the transponder is a King 76A - with an "older" serial number, 7506. I could post photography if it would be any use. Should be glad of any docs for it, too. Web searching did find me some for the 76C but none for 76A - and I am not the only one searching, apparently.

EBZH Kiewit, Belgium

Would a bent-open paperclip, stored in a convenient place, work too?

I've been flying for eight years and have only been asked to squawk ident once, as fas as I can remember. Of course with everybody in NL flying around with Mode-S there's not a lot to be gained by squawking ident, but even before the switch to mode-S it was very, very rare.

I've been flying for eight years and have only been asked to squawk ident once, as fas as I can remember.

FIS Munich (one of the three FIRs in Germany) does it 100% of the cases and most RADAR controllers, too. FIS Langen almost never does it. I guess they require their staff to have geographical knowledge :)

In the US one has to do it all the time as well.

I've been flying for eight years and have only been asked to squawk ident once, as fas as I can remember. Of course with everybody in NL flying around with Mode-S there's not a lot to be gained by squawking ident, but even before the switch to mode-S it was very, very rare.

In my recent post about ATC and being handed over with new squawks to the next station, I was asked to squawk ident by the Farnborough Lars Radar guys. I did wonder why as I was given a discreet code, I do have mode S, and it was switched on. I wondered why they wanted me to ident. Any thoughts welcomed. I dont think it can just be a 'Mode S' thing, unless I am mistaken.

Well, this is only a mode A/C transponder, and Brussels information do ask one to ID at first contact, I guess it's their way of making sure the pilot knows how to handle a transponder. As for the bent back paperclip: such contraptions do break sometimes, and I don't much fancy the idea of flying around with a bit of paperclip behind the transponder's front panel.

EBZH Kiewit, Belgium

As for the bent back paperclip: such contraptions do break sometimes, and I don't much fancy the idea of flying around with a bit of paperclip behind the transponder's front panel.

So get yourself something suitable, lathe, brass, plastic, whatever does the job. You won't be able to fly to many countries in Europe with your A/C transponder so I wouldn't invest too much effort in keeping it alive.

Do not forget that I fly a microlight. A transponder can never be mandatory for me. Its only advantage is that it improves my chance of exceptionally getting a clearance that I am normally not entitled to, such as crossing a CTR. As long as I can keep it going without too much cost/hassle, I will.

It also carries a repair tag from a US'an workshop, dated 2002, so it must be long past its youth - one more reason to not spend much money on it!

EBZH Kiewit, Belgium

Just popped the KT76c installation manual to you by email

Administrator
Shoreham EGKA, United Kingdom

We're doing the annual on my aircraft today, at the moment I'm taking a break, so I looked at my KT76A. The push button is firmly spring loaded out, moves about 6-mm and clicks at the bottom of its travel. Make sure it does that with whatever knob you make and I think you'll be fine. The button does not pull off mine with any reasonable force so i wonder how it came adrift?

In the US (for now) we are not required to identify ourselves involuntarily while flying so the ident feature does get used occasionally on initial contact with ATC. The King is a pretty good unit so while it may be of limited utility for you, I certainly wouldn't junk it. I'm 100% certain mine hasn't been worked on since long before 2002, and it works great. We did a transponder check a couple of weeks ago.

The KT76A should have an option for a remote mounted ident button. This would be far easier to install than fabricating a new button for the unit.

KT76A features

Maybe you have a button in the plane somewhere you're not sure what it does?

EHLE
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