COMM wiring for GNS 480

Hello... Looks like I will be installing a GNS 480 in my panel. I haven't had much luck having the wiring bundles made for me, so it looks like I will do it myself.

Really, I don't think it will be too difficult. It will be communicating with my Skyview ARINC, so I have those diagrams (easy enough).

I am needing help/assistance on the COMM part.

I currently have a MGL V6 which has be working great as my only COMM and Intercom. I had planned on removing the V6 and using the GNS 480 comm and buying a Skyview intercom.

Do I need to use any different kind of wire for the comm and intercomm? Does it need to be shielded?

I guess I am a little leary of wiring the comm up and don't want to introduce noise.

Also, would it be possible for me to keep the V6 comm/intercom and use the gns 480 as a 2nd comm (and not need to buy an intercom)? Would that require me buying an audio panel?

Thanks in advance

High Density Pins

I initially thought about wiring the GNS480 myself, but with 4 separate DSUB plugs, one of which has high-density pins, and my plan to connect to the Dynon ARINC and a TruTrack A/P, plus GPS feed to the Dynon transponder, with intercom connections...I paid Stein to make up a basic harness, and they provided a nice wiring diagram.

I went with the PS Engineering PM 3000 intercom to ensure that I could pick up all the audio inputs from the various boxes.

You did not ask, but...Why a 480? I presume you want an ifr-TSO'd gps? The 480 is a great box, but getting pretty old. You have to wonder how much longer Garmin will support it.
The average person can wire this stuff up, but estimate your time, then triple it!
Get the right tools, including crimpers (D-sub and high density D-sub, if needed). Use shielded cable (ground shield at one end only, float the other end) for everything other than power. If you have a dedicated audio ground then use a two conductor, shielded cable, with one wire the ground wire, the other 'hi'.
Take your time.

Edit: I'm not familiar enough with the V6 intercom to comment. But in general, these days with no ADF, no MB, maybe no VOR idents, there is a trend to using an intercom with multiple inputs, rather than a full-blown audio panel. Along with a switch (for mic and PTT) to select transmitter #1 or 2.

Congrats on the 480, Ryan. It's a great box. Yes, a little old like the previous poster mentioned, but since Garmin earlier this year released a software update for the 480 that gives it ADSB+ output capability on one of the RS232 lines, I'd like to think that means they intend to continue supporting them for a while yet (via the $$$ flat rate repair fee program used for all G-branded navigators including the current gen).

Like others mentioned, not all that hard to wire with the right equipment, some research, and your time. Just like building a plane. Mine's running to a PS engineering audio panel, wired per the GNS480 installation manual, without noise or squeals of any sort. Read the Dynon intercom installation manual, marry up the required connections to/from the GNS480 and MGL radio if you intend to keep it, and you should be most of the way home. The Dynon manual tells you where you need to use shielded wire and how to ground the shields.

You can run the 480 com into your V6 as a primary input or secondary if your EFIS is using primary. You can use a simple switch to kill 480 audio input when not needed and a dpdt switch to your mic jack to select which com to transmit on. Use the money for gas.

Thanks all. I have checked in on pricing to have the wiring bundles made for me. After a bit of sticky shock, that made it an easy decision for me to roll my own.

To keep it simple I will remove the perfectly working V6 comm. I really don't need 2 comms, as the 480 can also monitor a standby freq. So I will need to buy the Skyview intercom, build out the wiring for the intercom, 480 comm, 480 ARINC to the Skyview ARINC...etc

Once I get these all down on paper I may post my diagrams to check myself.

480 INTERCOM

''wiring for the intercom, 480 comm''

Correct me if I wrong but is the 480 not coming with a built-in intercom like the SL-30/40 radios??

Being an Apollo design I assume that it does..

So you could use that one Ryan but it won't work for the alerts off the Skyview...

Just my $0.02

Bruno

The hard part of the wiring is dealing with the shielded wires. Get some solder splices to help with that part to solder a regular wire to the shielding, which then will tie in with the other shield grounds at the intercom.

Be sure to cut the shielding back enough to clear the connector shells and don't forget to feed them all through a nice big piece of heat shrink. De-pinning later to install the heat-shrink is also time consuming and prone to installing the pins in the wrong socket.

Wiring

Ryan,

I just rolled my own entire panel based on a schematic from Stein. It's not difficult, one wire at a time. Buy or borrow the proper tools, someone in your EAA Chapter should have them. My strongest recommendation is to watch all the How To Videos on the Stein Air website. They are very well done and cover 99 percent of what you need to do. And don't be afraid to ask questions.

Best,
Jerry Folkerts

Some basic guidance... For a single installation, buy Steins D-sub pin crimper and the High Density positioner for it. Good value. Don't forget to buy at least 2 each of HD and standard density pin extraction tools - get the metal ones as the plastic ones just don't last.

On the topic of shielding, I'll jump up onto my soap box here... If there is ANY wiring in the airplane that MUST be done right, it's your audio wiring. Do not cut corners here. I can't tell you how many instrument panels I've crawled under to help find problems with audio hiss, squeals, whines, clicks, pops and buzzes. And it's almost always because the installer did not follow best practices. If you follow best practices you are almost guaranteed to never have a problem - that's why they're best practices!

Start with using shielded wire for all audio wiring. As has been mentioned previously, spend the money to buy the proper solder sleeve terminations (Spruce sells both Raychem and Sumitomo - the Sumitomo's are cheaper and every bit as good as the Raychem product). Terminate your audio shields at the source - in this case, the source is your intercom, then make sure your intercom has a most excellent physical ground. Isolate your headset jacks from the airframe by using insulating washers (again, Spruce sells them - you need 2 part number to make them work, an "inside" and an "outside" washer - they'll cost you less than two bucks per headset jack and are worth every penny). Ensure your coax cables are kept away from your audio wiring, and keep the alternator wiring and P-leads away as well - those are all big sources of noise.

The GNS480 isn't hard to wire, and it's a darned fine navigator, not to mention an approved ADS-B position source with the newest software installed. Don't try to eat the whole elephant in one bite - break the wiring down into systems. Start with the audio interface, draw it out on one sheet. Then use another sheet to draw out your serial interface wiring (Arinc 429 and RS232) and your discrete logic. Then use another sheet to draw out your analog interfaces (low level +/- signals to an external CDI). And most importantly, follow the manufacturer's instructions for wiring power and ground as the unit can be damaged if not properly powered.

While the 480 has the ability to monitor a standby frequency, there's no substitute for having 2 comms. It's just a lot easier to switch between radios than it is to switch between active and standby on the 480. Besides, if one radio goes belly up, it's far easier to have a second radio ready to go than it is to have to start fumbling for your handheld radio. With a second comm radio available in the $1K price range or less, this is money well spent.

OK, I'm stepping off the soap box now.

happy to report I have successfully wired my GNS 480. early indications appear all is working great. I ended up keeping the VAL 2000 Nav and adding an audio panel, and a new dynon comm too. sure feels good to put all that time and effort and have everything work. The comms sound great. Now I just gotta get the 480 arinc configured for the dynon SV.

Glad to hear you have been successful, Ryan. The 480 has a bit of a cult following, and for good reason. The GTN650 is only now starting to have all the functionality the 480 has had for many years.