Trig TT22 transponder issues

[Echo]

Installed my transponder this off season, passed the transponder check to make it legal. First flight with it yesterday. Called the local controlling agency to check it out. They had nothing on me, but they did once I cycled the transponder off and back on. I then realized that where the "ALT" is indicated on the lower right of the screen with the little airplane symbol was actually just 3 dashes instead. Multiple times in flight I noticed it kicked off to the dashes, and I wasn't broadcasting. It seems a reboot worked, but not for long. Running it with a premade wiring harness and L2 antenna, dual LiPo batteries. Anyone have any ideas?

Jordan
ASW20

[kevi...@gmail.com]

Contact Trig, they have the best service I have ever experienced with a instrument company.

Kevin
92

[Dan Marotta]

I agree with Kevin - Trig were very helpful when I had a wiring issue.
I could only suggest that you check that the pneumatic plumbing is
installed correctly and functioning properly.

--
Dan, 5J

[Echo]

No the altitude reported indicates fine. It's where the airplane flashes when it gets pinged. I'll check with their north American distributor and see what info they have.

[JS]

On Saturday, June 3, 2017 at 1:16:51 PM UTC-7, Echo wrote:
> No the altitude reported indicates fine. It's where the airplane flashes when it gets pinged. I'll check with their north American distributor and see what info they have.

Give them a call in Scotland on Monday morning. They are quite responsive.
Jim

[raxy...@gmail.com]

were you high enough to normally be in radar contact with ATC? Were you orientated so your antenna was not shielded from ATC by the fuselage? Do you have a long coax to the antenna? Do you have a low loss antenna cable? Do you have a ground plane under the antenna?

[2G]

The only thing in the manual that addresses this is this:

Warning Messages
If the transponder detects a problem, the screen will indicate WARNING and a brief statement of the problem. Depending on the nature of the problem, your transponder may not be replying to interrogations. Note the message on the screen and pass that information to your avionics maintenance organisation. Press ENT to clear the message; if the fault is still present the message will reappear.

My guess is that the transponder detected an impedance mismatch with the antenna and shut down transmissions to protect itself. A mismatch could be the result of a damaged coax (there may be no external signs of damage). Let us know what Trig says.

Tom

[Echo]

Will do. Mid continent (the North American distributor) said check connections. No screen messages. Gonna reset all hookups and try again this weekend...then it's a call to trig.

E

[George Haeh]

1. Where did you put your L2 antenna? I did fine putting it in the nose
after
shaping a balsa piece to fit.

2. How did you route the coax? With a lifting instrument panel you have to
be
careful the coax does not get mangled by adjacent hardware.

3. Are the coax connectors secure to the conductors, especially outer?

If it gets to the point that you might have to ship it out for diagnosis,
it might
help to hook up the removed components to a battery. If there's a major
airport within 50 miles you should see replies to TCAS interrogations from

the heavies. You don't have to be in the air to receive TCAS
interrogations.

But do double check the harness plugs are seated properly before doing
anything else.

[George Haeh]

[Echo]

Yeah the L2 is well behind the control mixing in the mid aft fuselage. It's strange to me because if it were a fault with the antenna or other, my understanding is it should throw a fault code. When it is on (like after I restart it), Nashville approach picks me up fine. I can't get a hold of trig, every time I call I get error messages, so not sure how to call over there if my provider and wifi options aren't working.

[son_of_flubber]

On Saturday, June 3, 2017 at 8:34:46 AM UTC-4, Echo wrote:
>I then realized that where the "ALT" is indicated on the lower right of the screen with the little airplane symbol was actually just 3 dashes instead.

This is confusing.

The dashes/airplane_icon are in the UPPER LEFT of the screen. My understanding is that the airplane_icon only flashes visible when the XPNR is replying to interrogations. The 'dashes' are displayed when it is NOT being interrogated. Do you think that the airplane_icon should be displayed all the time? Why do you think that the XPDR should constantly be replying to interrogations?

[Echo]

*Sigh*

I know how transponders work. No you don't get constantly pinged. Yes the plane is supposed to flash as it's being tagged by radar. No that's not what I'm talking about.

I meant to say text on lower left. Do you want a photo? It displays text: SBY/GND/ON/ALT corresponding to switch position. Mine works for maybe 20 minutes, then displays dashes where the text was. Same issue with a different hesd unit and transponder in my plane today. Starting to think it's the wiring harness, more specifically the data line connecting the head unit on the panel and the box in the back. Running dual batteries, both lithium...power supply shouldn't be a factor. Antenna shouldn't make a difference to the display. Still troubleshooting. Next step is to try another harness, and check mine for breaks and bad solders.

Jordan

[Dan Marotta]

When I first installed my TT22 about 3 or 4 years ago, I thought
everything was OK except that it failed the test. Closely monitoring
the display during startup revealed an error message displayed for such
a short time that I could not read it. I cycled the unit through
several power cycles reading the next word in the message each time and,
when I had the full message, I contacted Trig tech support. I believe
the engineer's name was Andy.

Andy told me that the message indicated a problem with the wire harness
so I took it apart (the end which I'd soldered on) and found one stray
strand of wire which was shorting two pins. I'm not saying this is your
problem, especially as you describe the temporal aspect of your
indications, but it certainly couldn't hurt to have a look inside the
connectors or even just ring out the harness with an ohm meter.

Good luck,
Dan

--
Dan, 5J

[Echo]

Today I discovered jiggling the connection between the L2 antenna and coax cable caused the issue. Made a new cable, issue appears resolved. A bit surprised since it was a Goddard cable, but works now. (I think/hope)

Jordan

[Darryl Ramm]

The Andy you spoke with may have been the CEO and founder Andy Davis. :-)

[Dan Marotta]

Now THAT's what I would call service! :-D

--
Dan, 5J