Topics

31

General Discussion / More audio pondering

« on: September 18, 2017, 04:21:36 am »

There are quite a few methods of getting PAW to our headsets and I am considering both a Bluetooth option (using a Bluetooth transmitter plugged into the 3.5mm jack) or running 3.5mm extension wires to the aux inputs of  Bose headsets. However, what happens one day when Bose rid themselves of the aux input (as David Clark have done) and only Bluetooth is available. As the Trig radios have just one aux input then we start getting into the realms of mixers if you want to wire in more that one input (in my case I want EFIS warnings to the aux radio input).

My musings caused me to consider wiring the output of the 3.5mm jack into the 'phone' wire to the headset and I'd really like to know if this is do-able or not. People start talking about impedance and such with audio and, about this, I have not the first clue but I'm sure there's someone out there who does 

So, put simply, could I have a wire from the PAW 3.5mm jack plug (where I chop the female plug off the end) and then solder that wire to the phone output on the back of my radio, that's obviously taking radio/intercom comms TO my ears? It's all mono, so I'm not considering the stereo case where I'd obviously have to deal with two wires.

32

General Discussion / Audio output to input

« on: May 06, 2017, 08:52:28 am »

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.

33

Technical Support / Power Supply

« on: April 29, 2017, 06:11:58 am »

A two-pronged question. The first, regarding power, I'm pretty sure I know the answer but I'd appreciate any thoughts on the matter. The second is something that I really don't know about but I know you users and experts will 

In my panel plan I am considering mounting an iPad using the Guardian Avionics mount. One of the options for the mount is a dual power supply, 5v and 2.7A per port. One port obviously goes to the iPad in the mount but would the other be an acceptable power source for a PAW unit?

Here's the power supply when it's not attached to the mount:  https://www.guardianavionics.com/ifdr-power-250-301-aircraft-remote-mount-dual-usb-port-for-panel-mounts

That's the power bit done; now to GPS position.

I know the PAW uses a GPS receiving dongle and this may well be all that is needed. Depending on the location of the PAW (mine would be behind the panel and below the coaming) a GPS mouse might be required for good reception. All good so far. What I have no idea about, having never used one in flight, is how the iPad receives and provides GPS position to the likes of Sky Demon. I know the iPad has a built in GPS receiver and there are Bluetooth units such as Bad Elf that can provide the iPad with GPS information BUT in the absence of such a device (a)is the internal GPS receiver sufficient in a light aircraft, especially if it is panel-mounted and, therefore, shielded by the panel and the surrounding equipment, as opposed to sitting on someone's lap or on the yoke and more importantly (b)does the PAW GPS position get sent to the iPad once it is connected by WiFi to the PAW box?

I can imagine that an internal GPS receiver might drop every now and again and that would be a good reason to couple up something like a Bad Elf. But if the PAW GPS position is getting beamed into the iPad then that would provide a much more elegant solution.

Cheers 

34

General Discussion / Antenna Location & GPS Input

« on: April 05, 2017, 10:59:35 am »

Hello everyone,

I'm in the absolutely rubbish position of not owning any sort of PAW system, nor even an aircraft. However, I plan to remedy that situation and have been spending far too much time looking at goodies for my potential craft and asking far too many questions of long-suffering but patient people, such as the excellent support at MGL (sorry Paul). My plan would be to install a permanent PAW system and I have read all the the documents on the main site regarding that AND antenna location, so I'm not just going for the easy 'answer my questions' without having done some homework 

My potential steed will be fabric covered (Stitts Polyfibre) and I'd really like to know if mounting one of the tuned low profile antennas in the tail would be a decent set up. Clearly it wouldn't have too much metal around it apart from the tube fuselage and I understand it would not be a good idea to actually mount the antenna to one of those (vertical) tubes. I THINK it would be acceptable for the ADSB antenna because of the incoming signal strength but it would be good to know about the P3I reception from back there. I suppose I am in the enviable stage of being able to think about 'extras' before the order is even in and may be able to plan ahead for a couple of ground plates to be mounted in the tail before it gets covered but, if possible, I'd rather keep things nice and protected inside the fabric......and fewer bits sticking out. So, has anyone done this in a fabric covered aircraft yet and can report on their findings?

The second absolutely trivial thing I was thinking about was reducing the number of GPS antennas I would (potentially) have. At the moment my plan is to run two MGL iEFIS units and both will have separate GPS antennas. If I permanent-mount the PAW then could I use a GPS output from one of those EFIS units instead of having a third antenna on top of the glareshield? I'll be using EFIS GPS position for input to the transponder for ADSB but even if I only run one GPS 'out' from each unit then the PAW can be fed the data. As I said, trivia and only a means to have two matchboxes instead of three on the glare shield.

I'll leave my meanderings there for now as I have so many thoughts about power supplies and filters for MGL EFIS that I would bore everyone to death and that's before I've even got a toy to play with.

Thank you for your thoughts and any information on these vital questions