Stratus ESG GPS antenna used for ....

MuseChaser

MuseChaser

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MuseChaser
One drawback to installing the ESG was brought up to me by my A/P. My Cherokee is IFR, but without any GPS so, as the VORs slowly go NA in my area, at some point I'll need to add one and it looks like the Garmin GPS 175 is about the cheapest way to do that, short of used gear. Given installation costs, the savings of used gear don't really make a lot of sense at least to me.. I could be wrong.

Anyway, the ESG requires the installation of the included GPS antenna. Can that antenna's signal also, in the future, feed the Garmin 175, or will I have to find another place on the roof to mount yet ANOTHER antenna? Or.... does the ESG have the ability, like the ES, to use the GPS data from the 175, thereby allowing me to use the existing ESG GPS antenna for the 175?

My A/P mentioned the redundancy of having a WAAS GPS in the ESG, but then eventually having to get another one for IFR, and suggested that maybe it'd be best to just go with the GNX375 now and be done with it. Would have been nice, but it's WAY out of my price range right now.

Thoughts? The ESG is going in on Thursday, so that's kind of a done deal at this point.
 
No. The GPS 175 can send GPS position data to a transponder but it does not go the other way for transponders with internal GPS.

Now that begs the question, can you hook a Stratus ESG to an external GPS source (GPS 175) and disconnect the ESG from the GPS antenna? If so, then can you use the Stratus GPS antenna on the GPS 175? I think on paper that antenna may not be approved for the GPS 175. The 175 (with STC) kit includes a GA 35 antenna and I don't believe it has the same hole pattern as the Stratus supplied antenna.
 
I knew that the ESG GPS data couldn't be used by a GPS navigator, but wondered if there was some kind of pass-through for the antenna signal itself to feed both units. The only passthrough on the ESG seems to be ADS-B Aux Pass-Through, labeled "Not Used" on the diagrams I have. At some point, I'd also like to see if there's a way to mount/interface my Stratux behind the panel Stratus 3i style... ;).. but that's not an immediate concern, and I don't know if that's doable either.
 
So far, I have not seen an installation approval for a GPS antenna splitter, but I know the devices exist. All posts from Garmin tech support (see beechtalk), appose them as do most avionics installers.
 
If a Garmin Navigator is in the planes future, a stratus ESG is not a good choice. You will ultimately have to change it to feed the Garmin navigator. The 375 would require more up front, but since it includes the transponder, it would be a good use of funds. Rather than a 335 or 345, for a later addition of a 175, I think it would cost less total dollars to just go with the 375 now and have it all done. A 335 or 345 with a 175 added later would be more total cost. A Stratus now would have to be pulled later if you want the 175 fed with ADS-B data.

My $0.02,
 
@MBDiagMan ... Thanks for the input, and believe me I did wrestle with this. There's just no way I can go $8000 plus another $1k or so for installation now... no way. I don't currently have an IR, but once I get the plane back on its wings I plan on resuming training towards it (which has endured two very lengthy, very annoying interruptions ... ) and hopefully getting it w/in the next six months. For now, the plane as is can be used towards that goal.
If I understand you correctly, there's no reason why I can't use the ESG as my adsb-out and transponder, and a 175 as my GPS navigator... I just won't be able to display adsb-IN on the 175. I can live with that, since I get my adsb-IN data via a Stratux and tablet now. Who knows... by the time I truly NEED to install a IFR-approved WAAS GPS navigator, other options may present themselves, and I'll have a better understanding of what I truly need. The fact that $9k is probably more than 1/3 the worth of my plane doesn't make it any easier to sink that much dough into it...but I know it would be money well spent. Again, thanks for the advice.. it's good advice, but I just can't take it right now.
 
The GNX-375 is indeed the ideal solution for those who need ADS-B and WAAS GPS, assuming you can absorb the initial cost. It's hard to get both capabilities for less cost. But adding a Garmin 175 later is an option, and you will have to add another GPS antenna for it. That should not be a big deal, plus you get some redundancy since a GPS 175 failure will not cripple your ADS-B transponder. Doing the installs in two goes will increase overall costs slightly, but will allow you to spread out cost over time. It is ALWAYS good to think about future upgrades when getting ADS-B, as you want your chosen equipment to communicate well with your likely future equipment. It would be a shame to get a pretty panel screen and not be able to display any data on it.

I went with an NGT-9000 since it has its own screen (more redundancy) and I don't know what I might get to eventually replace my GNS-430--but if it were now it would probably be an IFD-440, which interfaces with the NGT-9000 well. The NGT-9000 doesn't play perfectly well with the GNS-430, but that unit is already ancient technology, albeit robust and still working.
 
MuseChaser said:
The fact that $9k is probably more than 1/3 the worth of my plane doesn't make it any easier to sink that much dough into it...but I know it would be money well spent.
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If you like your plane and plan on keeping it a while, you can't really think about avionics investments this way. WAAS GPS and the capacity to get in-flight weather are two of the most effective safety enhancements you can install. It will make your flying easier and less stressful, especially as you train for and eventually fly IFR. I wrestled with the financial issue myself when installing my GNS-430 and STEC-20 more than 10 years ago. Those installs also necessitated installing a new, modern audio panel, and a GI-106A indicator as well, plus the removal of nearly 20 lb of useless stuff and reorganizing the panel. The total cost was nearly 100% of the (then) value of the plane. But it was either that or buy a new plane. (Upgrading planes to get better avionics is always a valid choice, but comes with other issues like any new-to-you plane.) The obsolete avionics just didn't cut it for reliability or for comfortable IFR flight. Ultimately, there is NO regret for spending on those installs, as it made flying IFR so much more easy and safe. Plus I have a plane I like to fly with an engine that is low-time and in excellent shape.
 
MuseChaser said:
Anyway, the ESG requires the installation of the included GPS antenna.
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No sir, that's not quite true. The installation manual (www.rstengineering.com) clearly states that any antenna that meets the specifications for the supplied antenna will work quite well. Also please note that the installation manual requires a length of coaxial cable to give a specified loss (i.e. the antenna has too much gain for the receiver input) which seems to be sort of a stupid design ... buying an antenna with too much gain and adding ballast (weight) with excess coax length to get the loss.

By the way, RST Engineering is in the final design phase of a GPS antenna splitter so that you can run two GPS inputs from a single antenna. Probably on the market a bit after Oshkosh. Target price is $35 or so.

Jim
 
Thanks for the input, Jim. Of course, you are correct... I should have stated that the ESG requires the installation of an "antenna that meets the specifications required" rather than the one "included," but for the sake of brevity and the point of this discussion I thought the phrase was OK. Apologies for muddying the waters a bit. VERY much looking forward to your antenna splitter! Thanks for the documentation completeness included w/ the ESG order, along with the antenna cabling and terminations. Great stuff.
 
So, if one were to install two G5’s would they have to install two optional roof top antennas? I know they have internal antennas but I’m a believer in the external being a better supplier. I would think Jim’s splitter would be perfect for such an installation assuming it’s acceptable.
 
Mooneys R Quicker said:
So, if one were to install two G5’s would they have to install two optional roof top antennas? I know they have internal antennas but I’m a believer in the external being a better supplier. I would think Jim’s splitter would be perfect for such an installation assuming it’s acceptable.
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FYI, The G5 STC install manual no longer allows for an exterior mounted antenna, only a glareshield mount antenna or WAAS GPS navigator input. In a dual install though, it only requires one to be connected to antenna (the AI)
 
Ryan Klems said:
FYI, The G5 STC install manual no longer allows for an exterior mounted antenna, only a glareshield mount antenna or WAAS GPS navigator input. In a dual install though, it only requires one to be connected to antenna (the AI)
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I doesn't make any senses either, thankfully you can still download all of the FAA approved revisions of the STC, and I could not find one statement anywhere from the FAA or Garmin that makes the latest version mandatory.

If there was something bad about a roof mounted antenna, there would be service bulletins and possibly an AD requiring corrective actions on all those aircraft that were completed using the STC revision that approved the roof antenna.

Just like the added diodes to the G5 LRU power wires, my first three G5 installs used an older STC revision, there were no diodes in the install manual then, nor is there a service bulletin/letter or AD to install the diodes in aircraft that don't have them.
 
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There is a splitter that will allow 2 GPS receivers to share an antenna. The Lynx manual recommends that if you don’t want to install a second antenna. The splitter costs about $300, but it works great. Any unit that doesn’t prohibit this should work. It does connect both units to the antenna, which is a requirement.
 
Jesse Saint said:
There is a splitter that will allow 2 GPS receivers to share an antenna. The Lynx manual recommends that if you don’t want to install a second antenna. The splitter costs about $300, but it works great. Any unit that doesn’t prohibit this should work. It does connect both units to the antenna, which is a requirement.
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See my post above. I am in the final test phase that will do the same job for less than $50.

Thanks,

Jim
 
weirdjim said:
See my post above. I am in the final test phase that will do the same job for less than $50.
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I didn’t catch that post. It would be nice to have a cheaper option. I have a lot of planes come in with the ESG, then we need to add an IFR GPS. In some cases I swap out the ESG for an ES, but there’s cost and paperwork involved.
 
Jesse Saint said:
I didn’t catch that post. It would be nice to have a cheaper option. I have a lot of planes come in with the ESG, then we need to add an IFR GPS. In some cases I swap out the ESG for an ES, but there’s cost and paperwork involved.
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There is a catch. You have to build it yourself (five surface mount parts on a double sided PC board).

Jim
 
@Jesse Saint and anyone else... looking at the pin diagrams for both the ES and the ESG..

Pin 3 on the ES is the RS232 input from the external GPS signal. The ESG has an internal GPS, and its pin 3 is described as "RS232-RX Maintenance" rather than as a GPS signal input. Pin 22 on both units is "RS232-TX Maintenance." I don't have the schematics to either unit, of course, and probably wouldn't totally understand them even if I did, but is it possible that pin 3 on the ESG COULD be used as an external GPS signal input, thereby functioning as an ES and just not using it's internal GPS? If so, this would make it possible, Jesse, in your earlier scenario to obviate the need to swap an ES for an existing ESG or splitting the antenna signal when adding an IFR gps; if pin 3 on both units is really a GPS-in signal, then the ESG could just act as an ES. NOT suggesting anyone try that on my guessing... I don't know enough to know anything.. just hoping someone who DOES know can comment.
Both the ES and ESG have aux +5v power out on pins 19/36, and RS232-TX GPS 1PPS on pin 6 which I'm assuming are what's used to drive the Stratus Adsb-in options. Wish I could figure out how to harness that GPS signal for my Stratux! The power part is easy... the GPS, not so much.
 
weirdjim said:
jim@rstengineering.com Send me a mailing address and I'll send you one for free IF IF IF you give me constructive criticism of what is obviously a VERY preliminary set of instructions.

Jim
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Done! PM sent, and thank you.. more than happy to offer observations on the directions or assist in any way.
 
Can you please share some installation info and pics if you can, i just got my ESG from Jim and will be replacing my KT76A. What crimper tool did you use? Thank you.
 
I'd be happy to help via PM. Do you have an A&P working with you? You'll need one (assuming it's going in a certified aircraft), along with the pin-out diagram of your altitude encoder if it's a parallel interface, and you'll possibly need to fabricate an aluminum brace of some kind for the back of the tray, depending upon your current installation, and a fused or breaker-protected 5w power supply. I bought this crimper..

https://www.amazon.com/gp/product/B01N3KVX8D/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

and it worked and still works great. Also bought a D-Sub pin extractor which wasn't the easiest thing to use but it worked and saved my tailbone when I misread the pin assignments on a plug and inserted a pin into the wrong hole. Make SURE you do good job terminating the antenna cable, and take care not to make any extremely tight radius bends. Putting mine in took me about six hours. I think I could do it in two hours now.. most of that time was spent figuring things out or correcting stupid mistakes.

Do NOT... repeat... do NOT put the GPS antenna near a com antenna or, if you do, prepare to purchase a TED 4-70 GPS notch filter or two... (one on the com antenna and maybe one on the ELT antenna)...

https://www.aircraftspruce.com/catalog/avpages/tednotch.php?clickkey=6369341

If you have any other questions, feel free to pm me. I got a LOT of great help from a few folks here, and two wonderful A&Ps, and would be glad to pass it on.
 
Thank you. I ordered the same crimper. I'm planning on installation some time next month when i get some time (my plane is in SC and i live in NY, 10 miles from KRME) Just trying to get everything ready.
 
Slavcha said:
Thank you. I ordered the same crimper. I'm planning on installation some time next month when i get some time (my plane is in SC and i live in NY, 10 miles from KRME) Just trying to get everything ready.
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That's quite a commute to your home airport! My plane is about 40 minutes from my house, and THAT drives me crazy.... especially when I have to drive 40 minutes south to fly twice that distance in half the time north! I'm not far from your area.. have subbed a few times for Rick Montalbano (phenomenal jazz pianist) at "The Savoy" restaurant in Rome. If I can be of any help in person, feel free to ask.
 
Thanks will do. The plane 78 PA-28-161 will be stationed at KRME some time next spring after i'm finished my PPL training in SC this winter.
 
Jesse Saint said:
I didn’t catch that post. It would be nice to have a cheaper option. I have a lot of planes come in with the ESG, then we need to add an IFR GPS. In some cases I swap out the ESG for an ES, but there’s cost and paperwork involved.
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Out of curiosity, Jesse... what IS the cost involved w/ going from an ESG to an ES? I queried Appareo directly about the possibility of using one of the pins on an ESG as the GPS signal input as specified by the pin diagram of an ES, and they affirmed that, hardware-wise, the ESG and ES are identical. The difference is in the firmware, but they were unable to get approval for a field swap of the software to go from an ESG to an ES. Can an Appareo dealer do this, or are you tied into physically replacing the ESG w/ an ES, allowing a trade-in value of some kind for the previous ES, and adapting the wiring harness?
 
I have talked to them. There is no way of doing this. I guess they we’re in a rush to get the ES approved that they didn’t want to just modify the firmware on the ESG to allow both options. It really stinks, because it would make it much more versatile, but it is what it is.
 
Jesse Saint said:
I have talked to them. There is no way of doing this. I guess they we’re in a rush to get the ES approved that they didn’t want to just modify the firmware on the ESG to allow both options. It really stinks, because it would make it much more versatile, but it is what it is.
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Thanks, Jesse. Soo... the question remains.. if a recently installed ESG comes into your shop, and it needs to become an ES for integration with a newly installed panel GPS, what does that cost.. in other words, trade-in/"trade-down" allowance on the ESG, and minor harness rewiring for the ES?
 
It all depends on what the current demand is for an ESG. I have a flight schoo” that is upgrading all of their planes to ads-b, so they are fine getting a used ESG. The cost to swap would be about $500 right now. A GPS splitter would be cheaper.
 
Looking forward to a documented install. Mine arrived the other day. I would like to find out what it isthat I do not know yet.
 
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