SOLVED! - Audio warning connections

[Smaragd]

Someone recently (and I can't find where) identified the RPi TRRS socket connections as Tip/L, Ring 1/R, Ring 2/Ground, Sleeve/Video. However what does PAW actually use for audio warnings? Is it mono/stereo/common? Which connections?

[exfirepro]

Hi,

See my original post at http://forum.pilotaware.com/index.php/topic,376.msg5117.html#msg5117 and Jeremy Curtis's diagram in the one following.

You are right with your connections. The output is mono, though as far as I can tell put out simultaneously on both left and right channels, so you could use left or right and ground. (I actually made up one lead with left and right both connected together to a single mono audio input (plus of course the ground) which also seems to work. Others have reported using mono trs leads successfully. I have certainly used a small 'stereo' speaker set with 3.5mm trs jack to good effect for testing with no problems. It very much depends on what your audio system requires.

Regards

Peter

[Smaragd]

Thank you Peter. My system requires a mono input and I didn't want to risk shorting differing L and R outputs together. I'm going to use your chopped TRRS cable idea but didn't want to solder up until I knew whether to use L or R. No problem if they're equivalent.

[Bobby]

Has anyone connected Audio to Dave Clark headsets ??

[Mike Mold]

Would this work? http://www.transair.co.uk/sp+Pilot-Avionics-PA-80-Video-Audio-Adapter-Cable-GA-Twin-Plug+2185

Or this?  https://www.amazon.co.uk/gp/product/B001UEBN42/ref=ask_ql_qh_dp_hza

[Moffrestorer]

Hi Mike,

Someone else recommended a cable like this on another thread, concerning the PAW audio. As you know, there are two sizes of jack plug on a standard headset. The larger, 1/4" dia plug is on the receiving, earphone side which is what you will need for this adaptor to inject audio into your headset.

The Transair description of this adaptor doesn't seem to make it clear if this is for receive or transmit because it talks about video recorders which I assume means you are taking a transmit microphone feed from it so you can video yourself when flying? That could infer that it has the smaller dia TX jack.

I guess a call to them might clear up any confusion.

Regards,

Chris

[Mike Mold]

Chris, I've just spoken to someone at Transair and they've confirmed their adapter has the 1/4" headphone jack & socket to pick up mic & headphone. (If it was the smaller (3/16") one it would only pick up the mic output.) The only questions are whether the 3.5mm plug has the right tip/ring combination to match the PAW audio out, and how long the 3.5mm spiral cable extends. Transair have a 30 day returns policy. I see it was SteveN who made ref to this product in another audio thread. http://forum.pilotaware.com/index.php/topic,405.msg5393.html#msg5393.

[Admin]

Or this?  https://www.amazon.co.uk/gp/product/B001UEBN42/ref=ask_ql_qh_dp_hza

This definitely works, I use one of these for testing purposes.
However, not sure how quiet your A/C is, this is not nearly loud enough for mine.

Thx
Lee

[Moffrestorer]

Hi Mike,

At first I thought Transair's reply made sense, but can't see how the 1/4" adaptor can pick up the mic output because I thought it was only wired through the 3/16" jack on headsets. Maybe it's commoned to the Rx jack as well these days. Not to worry, because it's the headphone input that your wanting to connect to!

Now the PAW (Rpi) output is 4 pole TRRS as I understand, tip, ring 1, ring 2, and sleeve. You can get a suitable cable  and cut it and solder the connections to a 3 pole 3.5mm jack or whatever but it's not really necessary. I have just used a 3pole jack/cable to connect to the PAW as Jeremy and Paul first suggested. OK it shorts ring 2 and sleeve together but that is no  big deal as you are effectively grounding the RPi video output which we are not using anyway.

Tip is LH audio, ring 1 RH audio and sleeve then becomes common ground. I believe it outputs identical audio on L and R, so in the case of your adaptor it would feed identical audio to both headphones I.e. Mono audio.

It worked for me, though I did connect through an amplified mixer that I strung together to feed the radio aux input, so both P1P2 hear it rather than direct to a headset as you propose.

[Mike Mold]

Thanks, for that. I'll bite the bullet with Transair and let you know how I get on.

Lee, mine's a Jodel D117 so not whisper quiet.

Mike

[Paul_Sengupta]

At first I thought Transair's reply made sense, but can't see how the 1/4" adaptor can pick up the mic output

It picks it up from the intercom/radio. If you speak, your voice comes through to your headphones too.

Sorry for not replying to your message Mike, I don't have much experience in audio feeds to headsets!

[Mike Mold]

That's OK, Paul. I bought the Transair adapter and a slim 3.5mm Mini Stereo Jack Plug to Socket Audio Headphone Aux Cable via eBay and it works a treat.

[Deker]

Hi,

Does anyone know what is inside the transair 1/4" to 3.5mm adaptor?
http://www.transair.co.uk/sp+Pilot-Avionics-PA-80-Video-Audio-Adapter-Cable-GA-Twin-Plug+2185
Does it contain any passive components or just simply splice the audio signals?

I have one of these from RS (1 > 2 adapter) which will allow me to plug into the normal panel 1/4" socket and provide one skt for the headset and another for my PAW audio alerts.
http://uk.rs-online.com/web/p/audio-video-connector-adapters/0392586/

Cheers,
Deker.

edit.
Just been looking at the Zaon manual page 17 http://www.aircraftspruce.com/catalog/pdf/xrxmanual.pdf
They use an audio transformer and a 150 ohm resistor.

[Mike Mold]

No obvious additional components that I could see inside the Transair unit, just the 3.5mm jack wires soldered in. Makes you think about the price!

I've since put an avometer on the connections in the Transair cable. The tip & ring of the 3.5mm TRS jack plug are combined and soldered to the tip of the headphone extension combination and the 3.5mm jack sleeve is soldered to the barrel. As Moffrestorer describes above.