PilotAware
British Forum => General Discussion => Topic started by: PaulSS on May 06, 2017, 08:52:28 am
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Good day again and time for more theoretical questions (as I still don’t have the aircraft or PAW…yet). I’m posting this here, instead of the MGL Forum because I’m pretty sure there will be people here who’ve done what I want but not necessarily on the other forum with the PAW.
This time I’m trying to get my head around combining the audio outputs from the PAW and an EFIS (MGL iEFIS Lite) into a single input to a Trig TY91 radio. Can it be done and, if so, can anybody give a step-by-step idiots guide (and it does need to be that for me). The MGL manual talks about using ‘general audio wiring techniques’ and I have no idea what that means, so let’s assume that level of stupidity on my part.
I know the PAW has the 3.5mm female jack port and this sends out alerts. I suppose my first question is does that 3.5mm jack lead to a single wire or are there two (I assume for stereo)?
The MGL EFIS has a 9 pin connector on the back and a male pin for audio. The manual says:
PIN 3 – Audio. This line contains a 0dBV level audio system for voice and other Annunciations. This output has a 1KOhm output impedance and should be connected to a standard audio input of an aircraft intercom system.
Audio output
The Lite features an audio output that can output standard iEFIS voice annunciations and sounds to intercom system.
The audio level is standard 2Vpp (0dBV) signal with about 1KOhm output impedance.
The output is not designed to drive headsets or speakers directly. It needs to be amplified. This typically forms part of the intercom system. Wire the output using general audio wiring techniques to a suitable input of the intercom system.
Inputs should be chosen that allow adjustment of audio levels and that will mute the input when radio transmissions are received.
So, would the Pin 3 (male) be connected to a specific type of audio cable or would any type of cable suffice? Would you somehow wire it up to two wires?
The Trig TY91’s manual tells me:
5.6.9 Auxiliary Audio Input
This input is continually routed to the headphone and cabin speaker outputs. It is intended for annunciators and identification tones.
Note: The audio bandwidth on the auxiliary input is limited, and is not ideal for MP3 players or other entertainment inputs. If such a device is connected, the mute settings should be enabled in configuration mode so that radio reception and transmission takes priority over the music input.
That seems okay but it is a single input (female) into a 25 pin connector.
So, if any of you chaps out there would be kind enough to explain in chimp language how I wire up a PAW 3.5mm output and a male single ‘prong’ output to, somehow, go into the single (female) input of the TY91 I would be most grateful.
BTW, I have Googled things and found you can combine two 3.5mm jacks etc but that doesn’t help me too much. However, I shall continue to investigate rather than just relying on everyone else to lead me by the hand.
Cheers.
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Hi Paul,
I found the audio output from the PAW unit to be too low in level to give sensible volume into headsets when the audio was connected directly to the aux audio input of my Becker radio intercom. Additionally, I wanted to get Nav program audio alerts from my iPad mini also so I decided to make an a Mixer/ Amplifier unit (in my case 3 channels, though I only use 2). It combines the output from the IPad ( read your EFIS) and PAW via individual volume controls, into a cheap Maplins audio amplifier, which I boxed up into a little plastic case. The amplifier need 12v so easily powered from the aircraft supply. A big advantage of having the volume controls is that you can turn down or mute the warnings if they get overwhelming at any point. See Audio Testing thread.
Note, others have used BlueTooth transmitters/receivers to give a wire free solution that maybe sorts out the audio levels also. Try using the "Search" function to get to the right threads.
Chris
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Thanks Chris.
I think making my own amplifier may be a bit much when I can't even figure out how to connect the wire to the EFIS and how many conductors are supposed to be there etc :-[
I promise I did try the search function and found threads with 'audio' but most of them were more to do with eliminating noise etc instead of an idiots guide to plugging stuff into the radio and combining it with another input.
I'll read the thread you've recommended and see if that helps but I've spent quite some time on Google today and am still not much wiser :'(
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Well, I managed to find the Audio Testing thread and I am now much wiser ;)
It would seem that I would need some sort of mixer to do what I originally wanted to do but the Bluetooth solution sounds a LOT easier. If I connected a Bluetooth transmitter to the PAW then I could just Bluetooth audio from the iPad (Sky Demon) AND PAW straight to the headset, while the EFIS could go (somehow....I still haven't figured that one out yet) to the TY91 radio/intercom.
Just a few questions about the Bluetooth boxes but I'll be rude and PM the guys who mentioned them on the other thread.
Cheers :D
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Surely you can only make one Bluetooth connection at a time to the headset?
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You're probably right, Paul. I have sent an email to David Clark and await their response. I knew my solution would be to good to be true :-\
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Bluetooth Headset will only bind to one additional audio input, but I don't understand the problem.
Feed the EFIS into the TY91. Feed the PAW into the Bluetooth Headset, or Vis Versa. Job done unless you still want Music ;)
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Ian,
Paul also wants to connect audio warnings from his iPad. Best option IMO would be a 3-way mixer, which will allow individual level control, then feed a single 'combined' feed into the intercom. Can't say at this point if any additional amplification may be required, but if so this could be built into the mixer.
Regards
Peter
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This time I’m trying to get my head around combining the audio outputs from the PAW and an EFIS (MGL iEFIS Lite) into a single input to a Trig TY91 radio.
If I connected a Bluetooth transmitter to the PAW then I could just Bluetooth audio from the iPad (Sky Demon) AND PAW straight to the headset, while the EFIS could go (somehow....I still haven't figured that one out yet) to the TY91 radio/intercom.
Ah, I didn't spot the creeping specification :D Mixer is the way forward.
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Thanks guys and sorry for my creeping specifications. I like that term and will stow it behind my ear for use another day. :)
IF the DC One-X headsets can accommodate more than one Bluetooth input then I think I'll have the Bluetooth transmitter fire PAW into my lugholes and the iPad can add the Sky Demon alerts (of which I hope to never hear any).
If the headsets can only cope with one Bluetooth input then I'll have PAW and just go with the Sky Demon visual alerts. Maybe have the iPad volume cranked up and might hear a squeak above the engine and ANR...yeah, I know.
I'll just have the EFIS connected to the audio input of the TY91 so I can avoid the added complication of a mixer.
The good thing about the Bluetooth connection from PAW to the headset is that if it gets distracting (in the circuit etc) then I can just hit the Bluetooth button on the headset and, hey presto, no more audio. I prefer this to having a switch I don't really want on the panel.....my cleanliness OCD kicking in again.
Any other ideas; I'm all ears ;D
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What alerts were you expecting from SkyDemon?
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This from the Sky Demon manual (as I say, not crucial but nice to have if possible.......hopefully I'd never see one):
Warnings and Navigation Aids
SkyDemon looks after you during flight by constantly monitoring your position and trajectory ahead, looking for potential hazards. Anything that could cause a problem to the flight is displayed as a warning, with a prominent notification onscreen and an audible alert. This is powered by our virtual radar technology and warnings can be configured in the Setup menu under Navigation Options on the iPad, iPhone and Android app.
You have the option to switch between VFR mode and Airways mode, and the warnings that appear are subsequently tailored to the mode you have selected. This means that in Airways mode airspace warnings that would usually apply for VFR operations will be suppressed, as they are no longer relevant. You will still see any warnings regarding terrain or obstacles, where applicable
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Even before PAW, I am happy to have these as visual warnings only. As you say not critical.
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This from the Sky Demon manual (as I say, not crucial but nice to have if possible.......hopefully I'd never see one:
Paul,
You'll certainly see plenty of obstacle and terrain warnings from SD in normal flight, though I've never bothered to connect the audio out. No reason not to do so though, but the mixer route is definitely the way to go as it allows rapid muting if any individual audio stream becomes overly distracting. The other trick if listening to multiple audio sources at the same time is to keep the volumes low, this allows your brain to subconsciously filter only what you currently want to listen to. A trick I have taught and used to good effect in several communications arenas.
Regards
Peter
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this allows your brain to subconsciously filter only what you currently want to listen to
My wife says I'm good at doing that already ;D "blah, blah, blah, BEER, blah, blah, SEX, blah, blah, blah, CURRY"
David Clark have responded that it's only one Bluetooth device at a time, so PAW off a BT transmitter to the headset it is and Sky Demon will be visual for their alerts. EFIS will go straight to the radio/intercom.
Now, about those filters being set in the PAW before going to the EFIS ;) ;)
I'm actually going to buy the PAW, even though I don't have the aircraft yet, because I'm feeling guilty about taking up peoples' time when I'm not even in the 'club'. At least if I've paid for the unit there's a reasonable basis for asking about improvements. I won't do it right this second because the Internet in China is, at best, bloody awful but in a couple of days when I get to Japan it'll be different.
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Hi Paul,
You won't regret buying it and running it at home (or wherever) will give you plenty of time to get used to it before you go to fit it in the plane.
Regards
Peter
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It'll be interesting to see how many P3I contacts I get in Western Australia ;D
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Paul
Careful on that one as the P3i frequency is not a free unlicensed frequency over there as I understand it, >:( but there is the facility to turn off the P3i transmit mode and play with all the other features. ;D
Alan
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It'll be interesting to see how many P3I contacts I get in Western Australia ;D
Paul, I assumed you were UK based - or are you just travelling out East ? ???
As Alan has said the P3i frequency is not 'legal' for use in Australia - check out previous Forum posts by Bill Maxwell.
Regards
Peter
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Thanks for the heads-up regarding P3I versus Oz rules. As you say, I could still get one and play with ADSB etc.
Peter, we live in Western Australia and I'm based in Japan but we plan on moving back to the UK next March (ish) and that's when I get compensated for doing so by my wife by getting my own flying machine ;)
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Ok Paul, all now CAVOK!
Regards
Peter
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Sounds like a good plan Paul :)
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I've hardwired by PAW audio out to my TY96 radio's AUX IN connection via a simple passive audio mixer (which mixes audio from various sources GPS, EFIS, PAW etc). The TY96's AUX IN level is set to max.
Unfortunately, whilst there's plenty of volume from the other devices, the PAW warnings are decidedly quiet and easy to miss, despite the PAW volume being set to 10 (on the latest version).
Now, I could, I suppose, build and install an amplifier or an active mixer/amplifier, but I'm wondering if its possible just boost the volume on each of the PAW audio files (using a audio editor like Audacity) to make things a lot simpler. It might help others with similar issues?
I'm guessing the WAV/MP3/AAC/whatever files are already at their audio max headroom?? but I thought I'd ask.
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grbvc,
Whilst my own PAW audio setup (Flycom with Icom radio) have always worked fine, we have had several reports of low audio using some radio/intercom combinations. Unfortunately, as you say, the Pi is already at maximum gain, so turning it up further is not an option. Several users have added a small audio preamp to the PAW audio out and this is definitely the easiest way to deal with the problem. Trying to boost individual warnings using external software will IMO almost certainly lead to grief.
Try a search on 'audio amplifier' from the forum home page.
Regards
Peter
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I have had success with using impedance matching transformers to match audio input without causing distortion.