ACK E-04 ELT wiring

[Swingwing]

Ahead of purchasing my ELT I built my rear wiring harness using Advanced Panel’s wiring diagram as a guide and included an unshielded 3 conductor wire to be used for providing GPS position data to the rear mounted ELT. Now I am installing the ACK E-04 ELT and their instructions are showing a shielded 3 conductor wire used to provide position data to the ELT.

I don’t understand the shielding need in this application. What risk of interference with other systems will I potentially have if I use the unshielded wires installed?

 

[wirejock]

ACK

Ahead of purchasing my ELT I built my rear wiring harness using Advanced Panel’s wiring diagram as a guide and included an unshielded 3 conductor wire to be used for providing GPS position data to the rear mounted ELT. Now I am installing the ACK E-04 ELT and their instructions are showing a shielded 3 conductor wire used to provide position data to the ELT.

I don’t understand the shielding need in this application. What risk of interference with other systems will I potentially have if I use the unshielded wires installed?

Given all the complaints, I would tie a shielded cable on to the existing and pull it in. Pulling that telephone cord was a real pain. It had to go first to clear all the snap bushings.

 

[lr172]

Ahead of purchasing my ELT I built my rear wiring harness using Advanced Panel’s wiring diagram as a guide and included an unshielded 3 conductor wire to be used for providing GPS position data to the rear mounted ELT. Now I am installing the ACK E-04 ELT and their instructions are showing a shielded 3 conductor wire used to provide position data to the ELT.

I don’t understand the shielding need in this application. What risk of interference with other systems will I potentially have if I use the unshielded wires installed?

I would expect none. It is a 4800 or 9600 baud RS-232 signal. Shielded wire is typically not necessary for that type of transmission. That would be in a normal case, but if you had noise issues it is likely the shielding would help.

 

[Canadian_JOY]

Take a look at this from the opposite side of the equation.

At the moment the thinking I'm seeing here is asking the question, "What is the ELT spewing out that could harm something else?"

Flip this thinking on its head. "What is everything else spewing out that could be picked up by unshielded wiring, potentially causing an uncommanded ELT activation?"

The shielding in this case is intended for both directions - conducted and radiated emissions and, even more importantly, conducted and radiated susceptibility.

We've seen in this forum far too many reports of the E04 ELT going off when it's not supposed to. Installing the shielded wiring will provide some protection against that eventuality.

With this having been stated, I still don't think we fully understand what is causing the ACK E04 to activate without user input.

 

[upperdeck]

My wiring was shielded and did nothing to prevent numerous false activations of this model.

I'd love to see statistics of false activations broken down my model. Something tells me the results would not surprise anyone...

 

[Canadian_JOY]

I watch web-based discussion forums pretty closely for ELT-related discussions. In terms of frequency of problems and particularly uncommanded activations, the ratings go like this from worst to best.

1) ACK E-04
2) Artex 345
3) everybody else
4) Kannad

Interstingly, I have just had reported to me the failure of a Kannad 406 Compact AF which I installed just one day shy of 10 years ago today. Of all the Kannad products I've installed or recommended to be installed, this quite literally is the first in-service failure. It failed the required 24 month bench test (required here in Canada) with low output power. It didn't fail by much, but it still failed. The owner is asking me about warranty coverage and I honestly have no clue what to tell him as I have never had an incident requiring warranty or repair consideration. This is why the Kannad product is still what I consider to be the best ELT in the general aviation marketplace.

 

[Swingwing]

Take a look at this from the opposite side of the equation.

At the moment the thinking I'm seeing here is asking the question, "What is the ELT spewing out that could harm something else?"

Flip this thinking on its head. "What is everything else spewing out that could be picked up by unshielded wiring, potentially causing an uncommanded ELT activation?"

The shielding in this case is intended for both directions - conducted and radiated emissions and, even more importantly, conducted and radiated susceptibility.

We've seen in this forum far too many reports of the E04 ELT going off when it's not supposed to. Installing the shielded wiring will provide some protection against that eventuality.

With this having been stated, I still don't think we fully understand what is causing the ACK E04 to activate without user input.

Very good point. I was not thinking of what will interfere with the ELT. With all the reports of false activations I should follow the installation instructions to the tee.