ADSB- GPS antennas - thinking ahead-

[N231SM]

Hello everyone, 

I have my 1980 231 K  interior stripped out for refurbishment. My goal in this post it to figure what I would be wise to install while she is naked. What I am trying to avoid is removing panels in the future to get ADSB in and out and any other niceties such as USB ports, rear seat armrest inputs,  etc. 

The plane is new to me. Here is my avionics package now: 

No ADSB
                        
I have one GPS antenna.

The mx20 is  a mirror of the 480 - (2 wires feeding the mx20)

KT76 transponder

Audio panel is KMA24. Right now, no intercom isolation. Everybody hears everything. 

Rear seat armrests now have oxy and headset ports.

Bottom line is: If you could add or change anything and running wires was not an issue, what do you suggest?

 

 

 

 

[N231SM]

Opps. To clarify, GPS is Apollo CNX80/GNS480 waas. 

[jaylw314]

I don't think the 480 can be used as a position source for any ADS-B unit, right?  That means you will need to run wiring for a new GPS antenna for the ADS-B unit at the very least. If you go above 18,000 MSL, you'll need a 1090 ES transponder.  That could at least use your old transponder antenna (I think).

[Jeff_S]

No, the GNS480 position source should be allowed for ADS-B. It was the first Garmin WAAS device. That is, unless there is some other ruling that I'm not aware of.  However, I don't know if the single GPS antenna will be sufficient...are you sure you don't have two? My old J had a GNS480 and two GPS antennae.

I believe the 480/MX-20 setup will let you benefit from a full ADS-B solution, and the most obvious one to get is the GTX-345 from Garmin. That should let you display everything on the MX-20.  Granted, this is all older equipment so if you want to go large then there are plenty of upgrade options, but I believe it will work that way.

However, not an avionics technician so others may correct me.

[Schinderhannes]

https://www.faa.gov/nextgen/equipadsb/installation/equipment/

The above link gives you a table with all certified combination for ADSB.  It might be helpful to sketch out you future upgrade path and install the required wiring even if you don't connect it at this point. At a minimum I would install the wiring for the backseats for a future intercom with stereo plugs.

  

 

[jaylw314]

1 hour ago, Jeff_S said:

No, the GNS480 position source should be allowed for ADS-B. It was the first Garmin WAAS device. That is, unless there is some other ruling that I'm not aware of.  However, I don't know if the single GPS antenna will be sufficient...are you sure you don't have two? My old J had a GNS480 and two GPS antennae.

I believe the 480/MX-20 setup will let you benefit from a full ADS-B solution, and the most obvious one to get is the GTX-345 from Garmin. That should let you display everything on the MX-20.  Granted, this is all older equipment so if you want to go large then there are plenty of upgrade options, but I believe it will work that way.

However, not an avionics technician so others may correct me.

I stand corrected, I assumed the 480 was old enough there weren't any approved pairs, but it looks like it is approved for most of the Garmin ADS-B stuff...

[kortopates]

20 hours ago, jaylw314 said:

I stand corrected, I assumed the 480 was old enough there weren't any approved pairs, but it looks like it is approved for most of the Garmin ADS-B stuff...

But you're actually right to assume that WAAS support alone is not sufficient since it's not. All the manufacturers had to add a specific protocol to provide all the data required for ADS-B out. Even though the unit is end of life, since it's owned by Garmin I would expect they have and assume you looked it up. So the unit will likely require a firmware update and then be good.


Sent from my iPhone using Tapatalk

Edited March 7, 2018 by kortopates

[Guest]

The latest software upgrade for the CNX80/ GNS480 give it position source for ADS b equipment, mine was done prior to the install.

Clarence

 

[Yetti]

Probably want to run a couple of RG-400 to the ceiling area rear of the baggage door.    

Stereo Headset Jack	S606H	4	$3.25	$13.00
Insulating Washer Set (1 Pair)	S892	4	$0.50	$2.00
22AWG Shielded Trio White Tefzel Wire	S906-3-22	30	$0.80	$24.00

[Yetti]

Probably the bigger question is are you going remote mount in the battery area or putting stuff in the panel

[Piloto]

One antenna location for GPS  that I found works very well is underneath the glareshield. If your glareshield is plastic locate the antenna as forward as possible. 

José

[DonMuncy]

28 minutes ago, Piloto said:

One antenna location for GPS  that I found works very well is underneath the glareshield. If your glareshield is plastic locate the antenna as forward as possible. 

José

Great minds, etc. That is the exact location where my hangar elf mounted mine. 

[McMooney]

hey is the mounting of the gps antennae here legal?  I'd like to do the same.

[jetdriven]

Sure, just be sure to list it on the 337 and the weight and balance.  be sure to reference the page number of the install manual.

 

 

[Guest]

Portable versus panel mount makes a difference.  Cirrus installed GPS antennae there, however for the WAAS installation they have to be installed on the roof.  It comes down to the STC and the install manual.

Clarence

[bradp]

Replace your existing Rg-58 with RG-400.  Do one run for your current  GPS.  Run an extra length and leave it in there for future use (I have sat and G5 GPS antenna on a second combined comant  antenna for example - but the install was easy because I had pre run coax).  Run two - one  for each of your com radios.  Run one for your transponder.  The proper BNC or TNC connectors are critical as is having the proper crimper and testing to make sure the shield isn’t shorted to the conductor is absolutely critical for coax wiring.   Weight wise should come out pretty neutral if you remove some orphan wiring If present   

Run wires for rear headsets (three conductor shielded (audio) and two conductor shielded (mic) - these are typically 22 gauge.  Stein is your preferred supplier followed by spruce.  Their quality is good. eBay stocks are hit or miss.  

[Yetti]

And since it is open and you are buying RG-400.   rerun your VHF antenna wires and remove and clean your antenna mounts.  Good ground plane is your friend.

[Yetti]

There is lots of errant RF signals from the radios and transponders in the panel area.  I would be concerned that it would jack with the the very weak GPS signals if you put the GPS antenna under the glareshield

[jaylw314]

9 hours ago, bradp said:

Run wires for rear headsets (three conductor shielded (audio) and two conductor shielded (mic) - these are typically 22 gauge.  Stein is your preferred supplier followed by spruce.  Their quality is good. eBay stocks are hit or miss.  

+1, That would be Steinair.com

[Aerodon]

I would do an Apollo SL15 audio panel / intercom now - not a big deal when interior is out, and more or less pin compatible with your KMA24.

Then GTX33ES paired with your 480 to get ADSB out.  Easy install if interior is out.  If you have more money, then do a 345 or 345R,

Aerodon

 

 

 

[Jeev]

On ‎3‎/‎6‎/‎2018 at 9:57 AM, jaylw314 said:

I don't think the 480 can be used as a position source for any ADS-B unit, right?  That means you will need to run wiring for a new GPS antenna for the ADS-B unit at the very least. If you go above 18,000 MSL, you'll need a 1090 ES transponder.  That could at least use your old transponder antenna (I think).

I have the GNS480 / MX20 combo and yes the 480 is the GPS source for my GTX345 ADSB transponder, all I needed was a software update.   You may also need a new GPS antenna if you have the old style.

 

SP

[Piloto]

6 hours ago, Yetti said:

There is lots of errant RF signals from the radios and transponders in the panel area.  I would be concerned that it would jack with the the very weak GPS signals if you put the GPS antenna under the glareshield

You have a valid concern and that was my concern too before I installed. But since it was an easy installation I went and try it. On the first try it pick up the GPS signal inside the hangar with all the radios on. Because the coax run is short signals are strong and stable. In-flight there is no signal loss on any heading while turning.

José

Edited March 7, 2018 by Piloto

[Guest]

3 hours ago, Piloto said:

You have a valid concern and that was my concern too before I installed. But since it was an easy installation I went and try it. On the first try it pick up the GPS signal inside the hangar with all the radios on. Because the coax run is short signals are strong and stable. In-flight there is no signal loss on any heading while turning.

José

It’s only that good because you soaked it in WD40!

Clarence

[Yetti]

6 hours ago, Piloto said:

You have a valid concern and that was my concern too before I installed. But since it was an easy installation I went and try it. On the first try it pick up the GPS signal inside the hangar with all the radios on. Because the coax run is short signals are strong and stable. In-flight there is no signal loss on any heading while turning.

José

Putting the alum under it is probably helping alot since it forms a good ground plane.  Making it bigger than the antenna would help a bit more.

 

[jlunseth]

Here’s what I think.  I have an MX20.  I wouldn’t rely on that for providing ADSB In or much else for that matter.  I know it has the capability, but it is not supported by Garmin any longer.  You can’t get parts or have one repaired.  If it fails, you have to either find another used MX20, or install something else, like a GTN750.  The biggest problem I have with my MX20 is the classic, aging computer based product issue.  The processor is by now probably 15 years old and does not have the processing power to handle much input, especially more modern input which is going to be quite a bit more data.

Here is what I would do.  Get a KT74 to replace your 76.  That is your ADSB out, provided you can get your GPS data from the 480.  I don’t know if you can or not, I don’t know that unit.  Then get a Stratus 2S and display the traffic and weather on Foreflight on an iPad.  Works really well and doesn’t require anything like the investment that panel mounted gear does.  Probably at some point you are going to feel the urge to replace the 480 with more modern technology.  At that point you can consider whether to display traffic and weather on, say, a 750, or whatever the then-current technology is.

My MX20 periodicallly does “Safety Shutdowns.”. Scares the crap out of passengers because they think a critical system is halting.  It is just a matter that the processor is overtaxed and shuts down to preserve itself.  I get XM weather via a GDL69A, which I like, but it does tax the processor in the MX20.  That is really old technology by now and I would not rely on it being able to handle much.