Trig TY91 Loss of Sidetone

[N867SP]

Just spoke to MidContinent and they said to pull the units and send them back. Warranty starts at date unit was put into service (aka first flight) 2yrs. Even out of warranty pricing is very reasonable, $100 OH exchange for the remote, $350 OH exchange for the transmitter, plus the 2yr warranty restarts from date of OH.


Pete Meyer
Severna Park, MD
CCK-1865-0078
✈️N9PW

UPDATE: spoke to MidContinent and they said that both units needed software updated and that could be the reason for the screen going black. Said the sidetone would need a board replacement. Unfortunately they have to get the board from Trig and that takes a parts requisition and 10-15 business days. Seems like in this day you can pretty much have any part in your hand in a few days. Glad that they found the problem and are fixing it.


Pete Meyer
Severna Park, MD
CCK-1865-0078
✈️N9PW

[N867SP]

Well that was a short lived fix. Mid continent/ Trig did not repair under warranty, so I paid to get the unit back. Worked for about 2 months and we are back to no side tone. Tried with and without intercom, tried front and read headsets, Bose lemo and standard GA Dual plug headsets. Planning on calling mid continent tomorrow to see if they have any ideas. They had to replace a board in the unit previously, seems odd that the same failure would happen again. First unit last 200hrs, this one has lasted about 20hrs.

Has anyone else experienced this issue with the Trig TY91?


Pete Meyer
Severna Park, MD
CCK-1865-0078
✈️N9PW

[mikesutton]

Two months does seem short lived, interesting to me that it died a slow death versus going out quickly. I presume it suffered the same fate as previously, black screen as well or just no sidetone? I know this drill gets old fast, having to try and isolate what is and isnt working. You are getting headset audio from the com itself - with the intercom off you can still hear ground or atis, and you can communicate between the front and back seats thru the intercom correct?

If the only thing that isnt right is that you have no sidetone when transmitting, and you can hear and speak thru the intercom then you have just proven that the mic and headphone wiring to and from the jacks and to and from the intercom is correct. If you can hear ground or atis or another aircraft then your receive portion of the radio is working and you again have proven the jack wiring, same with intercom..if you can talk between front and back, it has to be within the com.

One thing you might check, just because it may get asked about, is the vswr of the antenna itself. Make sure its around 2.0 or less, up to 2.5 is marginal and over 2.5 is high. That tends to be more of a transmitted audio problem but who knows how the Trig unit might deal with it internally. That I am aware of we have not had large amounts of problems with the Trig, though I am not in a position to hear about every one that has left the facility, anecdotally I have not heard about them being too much of a problem child.

Best of luck on this

Mike Sutton
Cubcrafters Avionics

[N867SP]

Two months does seem short lived, interesting to me that it died a slow death versus going out quickly. I presume it suffered the same fate as previously, black screen as well or just no sidetone? I know this drill gets old fast, having to try and isolate what is and isnt working. You are getting headset audio from the com itself - with the intercom off you can still hear ground or atis, and you can communicate between the front and back seats thru the intercom correct?

If the only thing that isnt right is that you have no sidetone when transmitting, and you can hear and speak thru the intercom then you have just proven that the mic and headphone wiring to and from the jacks and to and from the intercom is correct. If you can hear ground or atis or another aircraft then your receive portion of the radio is working and you again have proven the jack wiring, same with intercom..if you can talk between front and back, it has to be within the com.

One thing you might check, just because it may get asked about, is the vswr of the antenna itself. Make sure its around 2.0 or less, up to 2.5 is marginal and over 2.5 is high. That tends to be more of a transmitted audio problem but who knows how the Trig unit might deal with it internally. That I am aware of we have not had large amounts of problems with the Trig, though I am not in a position to hear about every one that has left the facility, anecdotally I have not heard about them being too much of a problem child.

Best of luck on this

Mike Sutton
Cubcrafters Avionics

MIke,

Thanks for the response. Yes the only issue is not side tone. Intercom works perfect, i can hear any and all frequencies I tune in and they can hear me too. Needless to say I have been asking all I speak to over the radio how they hear me and all have been loud and clear, just as I hear them.

The side tone, as it did previously, didn't just go away and stay away. Just one start up it wasn't there and then a few transmissions later there it was. Then stuck around for a few flights, then gone never to be heard from again.

VSWR wasn't something I'd ever heard of previously but after some googling I got some more info. The ant and ant cabling I installed was what came with the wVFR panel kit package.

I'll have to do some more investigations to see how and what is needed to measure VSWR of my ant and coax.


Pete Meyer
Severna Park, MD
CCK-1865-0078
✈️N9PW

[mikesutton]

Im not actually certain that the VSWR will be the culprit, if its too high the amount of transmitted power that is reflected back down the coax to the radio is so high that it seriously reduces your range when you transmit and it also damages the transmitter over a long enough time period. What Im reading here does not make me think its a vswr issue but not knowing the internal design of the trig unit, it would not hurt to check it.

We use a Bird thruline watt meter, but I doubt youd want to buy one for a one time check, you can also use one for any HF/VHF communication, typically they will handle up to 100w. They are common within the amateur radio community and I cant think of an avionics shop that wouldnt have one. Id bet you can find someone who has access to one and maybe you can get them to check your aircraft. It just goes in series between the com and the antenna and you measure the transmitted and the reflected power levels.

Sometimes there is no rhyme or reason in this stuff, sorry to say. Ive seen the very rare problem child that just does not respond, it will pass bench tests and work fine for some time period and then it wont, but those are rare. If you have a clean install, which it appears you do, and the rest of the audio is ok and it appears it is, sidetone is pretty limited to what is created inside the radio. The fact it is in a kit should be pretty much irrelevant.

Thanks

Mike Sutton
Cubcrafters Avionics

[N867SP]

Im not actually certain that the VSWR will be the culprit, if its too high the amount of transmitted power that is reflected back down the coax to the radio is so high that it seriously reduces your range when you transmit and it also damages the transmitter over a long enough time period. What Im reading here does not make me think its a vswr issue but not knowing the internal design of the trig unit, it would not hurt to check it.

We use a Bird thruline watt meter, but I doubt youd want to buy one for a one time check, you can also use one for any HF/VHF communication, typically they will handle up to 100w. They are common within the amateur radio community and I cant think of an avionics shop that wouldnt have one. Id bet you can find someone who has access to one and maybe you can get them to check your aircraft. It just goes in series between the com and the antenna and you measure the transmitted and the reflected power levels.

Sometimes there is no rhyme or reason in this stuff, sorry to say. Ive seen the very rare problem child that just does not respond, it will pass bench tests and work fine for some time period and then it wont, but those are rare. If you have a clean install, which it appears you do, and the rest of the audio is ok and it appears it is, sidetone is pretty limited to what is created inside the radio. The fact it is in a kit should be pretty much irrelevant.

Thanks

Mike Sutton
Cubcrafters Avionics

Thanks for the explanation, I actually know a few armature radio guys who are also avionics techs. I'll bounce it off them. I've also reached back out to Bruce and MidContinent and see what his thoughts are. I'll let you know what I find out.

Pete


Pete Meyer
Severna Park, MD
CCK-1865-0078
✈️N9PW

[N867SP]

So heard back from MidContinent and they are sending out a loaner unit for me to try out while I send mine back for further investigation. They are baffled to as to why I'm having this issue.


Pete Meyer
Severna Park, MD
CCK-1865-0078
✈️N9PW

[mikesutton]

Sounds like they at least are willing to say we dont know why....and I can live with that, an honest answer is better than a smoke screen. If it were possible, I would still check the VSWR, just to make sure there isnt an issue there. Its basic radio 101, the outgoing signal needs a good ground plane and the ground plane needs a good electrical bond to structure for the whole com system to perform ideally. If the reflected energy is too high it can cause internal damage, and all coms need a good ground plane with a very low resistance path, good electrical bonding to the structure, like in the 30 milliohm range and you cant measure that low with most handheld fluke meters.

Having said that, a vswr problem typically will show up with symptoms like low range or garbled audio reception at the receiving end, but I have no idea what Trig coms are doing internally so I cant say what else might be affected by a vswr thats too high. It would be worth checking just to know. Typically you may see a bell curve, with numbers say......2.5 or so at each ends at 118 and 136 and then lower in the middle of the band around 127. I cant give you any exact values but you get the idea. Id be interested in hearing what they find.

Thanks much

Mike Sutton
Cubcrafters Avionics

[N867SP]

Sounds like they at least are willing to say we dont know why....and I can live with that, an honest answer is better than a smoke screen. If it were possible, I would still check the VSWR, just to make sure there isnt an issue there. Its basic radio 101, the outgoing signal needs a good ground plane and the ground plane needs a good electrical bond to structure for the whole com system to perform ideally. If the reflected energy is too high it can cause internal damage, and all coms need a good ground plane with a very low resistance path, good electrical bonding to the structure, like in the 30 milliohm range and you cant measure that low with most handheld fluke meters.

Having said that, a vswr problem typically will show up with symptoms like low range or garbled audio reception at the receiving end, but I have no idea what Trig coms are doing internally so I cant say what else might be affected by a vswr thats too high. It would be worth checking just to know. Typically you may see a bell curve, with numbers say......2.5 or so at each ends at 118 and 136 and then lower in the middle of the band around 127. I cant give you any exact values but you get the idea. Id be interested in hearing what they find.

Thanks much

Mike Sutton
Cubcrafters Avionics

So as an update, MidContinent warranted their repair, sent me a loaner and I sent mine back in. I pulled apart all wiring, grounding, antenna, etc. Checked and cleaned all connections. Had the guys at the avionics shop come out their eyes on it, reassembled and no sidetone, removed my radio and installed loaner, sidetone was back. Just got my radio back today from repair and will swap it out again and see if I have sidetone. Haven't found someone that can check my vswr, but still looking. Fingers crossed.

Pete


Pete Meyer
Severna Park, MD
CCK-1865-0078
✈️N9PW