GDL-82 Install Time

[Igor_U]

Just an additional date for OP:

A well know avionics shop in Seattle area just quoted my friend 17h of install time on his Decathlon. Not a Mooney but then can't be much different...

It might seem a lot but every single task adds up. Good luck.

 

[N231BN]

I'll be putting one in a Cessna 207 soon so I'll let you know.

[David_H]

Thanks for the input everyone. The KT76A was able to be brought back to life again... which was good news.

A slot in the local avionics shop is now scheduled for later next year for a Stratus ESG install. We’ll see what happens before then. However, I don’t see many new things being rolled out before 2020. I’d really like to be wrong though.

Edited November 16, 2018 by David_H

[skykrawler]

With regard to Garmin's patent infringement lawsuit....I suspect it is more about how the signal is monitored not the fact that it is obtaining the code by monitoring the transponder transmissions.  RF couplers  are commonly used to monitor transmissions.   My FreeFlight has that capability, but I switched to direct connection.  The requirement is to a have a control head with which to verify the code used by the ADS-B transmitter.   The engineer at FreeFlight explained to me that in the circumstance that the transponder is not interrogated by secondary radar (out of coverage) then the transponder does not emit the signal that the RF monitor needs.  If the transponder code is changed the UAT will not know.  Also, having read the MOPS and RTCA documents, the ADS-B messages do not actually contain the squawk code - all they have is an indication of VFR/IFR and perhaps emergency - a couple of bits.   If you think about it, why is the squawk code needed if you have the unique ICAO address which is the encoded tail number?  Transmission time is precious.

What say the avionics experts?

[Jerry 5TJ]

The UAT box can cause the local transponder to reply by sending a low power interrogation. A mode 3 interrogation is at its simplest just two 1030 MHz RF pulses:

The P2 SLS pulse may be omitted.

In a GDL82-like device the pulses can be coupled into the coaxial cable at very low RF power.  

There is no technical reason a UAT could not know the squawk code of a co-located operating transponder.  

[carusoam]

So sayeth Jerry!

Jerry’s expertise is starting to really show!

Best regards,

-a-

[skykrawler]

True, and that is an interesting solution ... if it doesn't violate any TSO spec for transponder operation.  In this case the design would need other details such as when and when not to simulate the interrogation, etc....all the way to certification.    And this is about the point of the patent infringement, the patent was awarded in 2012.  The Wright brothers patented and worked hard defending their methods for aircraft control.  Patents are a double edged sword, they are important for businesses to make large R&D investments.

[Marauder]

So sayeth Jerry!

Jerry’s expertise is starting to really show!

Best regards,

-a-

 

I just live for it when Jerry talks electrons. Such a humble EE.

 

 

Sent from my iPhone using Tapatalk Pro

[Mark Pavinich]

Need help with the particular scenario: 
IFD440 and GDL 82

Configured ADS+B G2 format 
SIL is failing almost at 100% on the ADS-B test
Everything else passes without any issuess.On the ground, everything appears to check out. 
Let me know if I am missing anything.

[LANCECASPER]

13 hours ago, Mark Pavinich said:

Need help with the particular scenario: 
IFD440 and GDL 82

Configured ADS+B G2 format 
SIL is failing almost at 100% on the ADS-B test
Everything else passes without any issuess.On the ground, everything appears to check out. 
Let me know if I am missing anything.

The GDL-82 isn't hooked up to the IFD440. What transponder is the GDL-82 hooked up to?

[Cruiser]

try ADS-B +

or GDL-88

or Capstone Trfc+Wx

[Mark Pavinich]

The transponder is GTX327

[Mark Pavinich]

Well, I finally obtianed the answer.  The IFD is not an approve GPS source for the GDL 82.

The only method for this to work is to run another antenna and have the GDL 82 connected to that WAAS antenna without using the IFD for the GPS source.

FYI the 327 transponder does not have any impact on this scenario.

[LANCECASPER]

The only advantage I see to a GDL82 is for those without a WAAS GPS. There are better options if you have an approved WAAS source.,

[Ned Gravel]

1 minute ago, LANCECASPER said:

The only advantage I see to a GDL82 is for those without a WAAS GPS. There are better options if you have an approved WAAS source.,

@LANCECASPER 

I have a WAAS GPS and I do not see those better solutions (for the price range of $2,000 to $2,500).  The uAvionix one is OK, but I want a switch on the panel to turn off the ADS-B transponder (in conjunction with turning off the Mode C transponder when that is appropriate such as formation flying) and the uAvionix one turns off the strobes with it.  

So, before I go spending the money on a GDL-82, I would very much like to read the options you mean.

[LANCECASPER]

4 minutes ago, Ned Gravel said:

@LANCECASPER 

I have a WAAS GPS and I do not see those better solutions (for the price range of $2,000 to $2,500).  The uAvionix one is OK, but I want a switch on the panel to turn off the ADS-B transponder (in conjunction with turning off the Mode C transponder when that is appropriate such as formation flying) and the uAvionix one turns off the strobes with it.  

So, before I go spending the money on a GDL-82, I would very much like to read the options you mean.

For many people who have a legacy transponder like a KT76A, it makes sense to get a solid state Extended Squitter transponder like a King KT-74, Trig 31, Avidyne AXP340. You can find used examples of these for +/- $2000 and you get the advantage of 1090 (international operations) and a transponder which should be much more reliable. If you want to go brand new, a Garmin GTX335 is only about $1200 more than the GDL82.

[Ned Gravel]

7 minutes ago, LANCECASPER said:

For many people who have a legacy transponder like a KT76A, it makes sense to get a solid state Extended Squitter transponder like a King KT-74, Trig 31, Avidyne AXP340. You can find used examples of these for +/- $2000 and you get the advantage of 1090 (international operations) and a transponder which should be much more reliable.

Thanks Lance.  I checked the standard prices from sportys and spruce and all but the Apero one are north of $3,000.  If you know where I can get something like a Trig 31 or a KT 74 for the price of the GDL 82, it would be worth my while to chase it.  Important to me because Canada will be using the 1090 system (in about five years when that is mandated for us here).

[LANCECASPER]

3 minutes ago, Ned Gravel said:

Thanks Lance.  I checked the standard prices from sportys and spruce and all but the Apero one are north of $3,000.  If you know where I can get something like a Trig 31 or a KT 74 for the price of the GDL 82, it would be worth my while to chase it.  Important to me because Canada will be using the 1090 system (in about five years when that is mandated for us here).

Here's a start:

 

https://www.ebay.com/itm/Trig-Avionics-TT31-Mode-S-Transponder-00220-00-WITH-EASA-FORM/283352362299?hash=item41f91ded3b:g:BB8AAOSw-QBcSvO7&frcectupt=true

 

 

 

 

 

 

https://www.beechtalk.com/forums/viewtopic.php?f=44&t=166569

 

 

 

https://www.ebay.com/itm/Avidyne-AXP340-Mode-S-Transponder-with-ADS-B-200-00247-000/223499211797?epid=2170424763&hash=item3409975415:g:eMkAAOSwGJ5cwg~D&frcectupt=true

 

 

https://www.ebay.com/itm/ADSB-TRANSPONDER-AXP340/113734504309?epid=2170424763&hash=item1a7b1acf75:g:rw8AAOSwrJRcyhlr&frcectupt=true

 

 

[Ned Gravel]

Lance:

I guess I should have mentioned that I may have a little difficulty purchasing avionics off of e-bay or amazon.  These places obviously have better prices, but not that much better than dealing with a reputable shop.

[LANCECASPER]

1 minute ago, Ned Gravel said:

Lance:

I guess I should have mentioned that I may have a little difficulty purchasing avionics off of e-bay or amazon.  These places obviously have better prices, but not that much better than dealing with a reputable shop.

No problem, here's a new one for $2045: https://avionicssource.com/product/avidyne-axp340-new-surplus/

[Mark Pavinich]

Well --- the only way that we were able to pass the ADS-B test was not to use the IFD. 

Installed another antenna just for the GDL82 used the GPS on the GDL-82 and BOOM 

Everything passed without any issues.

[carusoam]

Great follow-up, Mark!

 

Fantastic shopping advice, Lance!

 

Thanks to big G... for being big...  

Best regards,

-a-

[MB65E]

Neat Device, but has anyone been able to use the waas source from a 530/430W for the GDL82 yet? 

I am on the fence about upgrading my 330TXP to ES or installing a GDL82. I like the simplicity and idea of the GDL82, but it looks like one more step than just the ES upgrade. 

Rather not mount another identical wass antenna on the exterior if I don’t need to. 

-Matt

[Cruiser]

Yes, GNS series will work 

[LANCECASPER]

6 hours ago, MB65E said:

Neat Device, but has anyone been able to use the waas source from a 530/430W for the GDL82 yet? 

I am on the fence about upgrading my 330TXP to ES or installing a GDL82. I like the simplicity and idea of the GDL82, but it looks like one more step than just the ES upgrade. 

Rather not mount another identical wass antenna on the exterior if I don’t need to. 

-Matt

You already have everything except the -ES upgrade. Upgrade the GTX330 to an ES - or buy a used ES and sell your 330. Run your WAAS position from the Garmin 530/430W and you have 1090 out. Why add the GDL82 and only have 978 out? The GDL-82 was designed for people who didn't have a WAAS position source in a panel mounted GPS.