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Transponder encoder


NC Bill

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One thing I love about aviation is that you constantly are learning new things.

 

Like Fast Eddie replying to a post asking where's your encoder? There are such things? 

 

Well as most others know there are and they're separate from the Garmin transponder.

 

But I can't find one in my plane. So a question if anyone knows the answer.

 

Mine is the first CTLS retrofitted in 2010 with SKYVIEW SV-700s and a GTX-330. Would it be possible that the encoder is contained in the DYNONS? Anyway to check?

 

Second question. Then am I correct assuming the encoder is simply the source of altitude info for the transponders Mode C?

 

TIA,

 

 

 

 

 

 

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The answer is likely yes to both of you questions. The standard Dynon D100/120 combo used output fron the D100 to provide altitude information to the Garmin transponder. I would bet that the Skyview does the same. It is likely a setting in the unit that needs to be set up correctly. I ask earlier if you had done an update to the Skyviews recently in this or your other post about fuel pressure. The update could have changed your settings. This could be the cause of both problems. I had an airplane indicating lower than normal oil pressure one time, only to find it had the wrong type sender selected in the Dynon.

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The altitude info comes from the Skyview and is fed to the transponder mode S transponder module, if using a SV-XPNDR-261/2

He is not using the Dynon transponder module. He has a Garmin 330 which he stated in his post. I answered the question based on the equipment he said is in the airplane.

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So what, YOU questioned whether Skyview sends the altitude info...it does.   So I am answering your question, not his and providing additional information on the transponder module Skyview uses.

Where I used the "guess" in the other thread was not in the form of a question. It was merely the regional use of the English language. The word could be changed to "suppose" or "figure" with the same basic meaning. The reason I said it that way is, because I didn't take the time to look up the answer from a reliable technical source.

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Just in case there are those on this forum who don't know - the CTLS has come with Skyview since 2008. My 2010 has the same display units as the Si, although, of course, some of the info displayed is different because of the engine.

That would be impressive, since skyview was not announced until november 2009, and shipments did't begin until dec 09 :)

 

http://www.dynonavionics.com/docs/news_SkyView_prices.html

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Informative thread.

 

Traditionally, the encoder was a separate and relatively simple/inexpensive remotely mounted altimeter with encoding paraphernalia added.

 

Even my Cirrus with relatively advanced Avidyne screens had one.

 

And here's the one in my Sky Arrow:

 

14953161824_92636cc8b2_z.jpg

 

I think this is the inexpensive Ameri-King used in both planes:

 

http://www.skygeek.com/ak350.html?utm_source=googlebase&utm_medium=shoppingengine&utm_content=ak350&utm_campaign=froogle&gclid=CjwKEAjwwo2iBRCurdSQy9y8xWcSJABrrLiSbcphqymGn4MJNesEC-5wcOql3Qades9Ooo4hvlPM4RoCWpjw_wcB

 

A small screw on the encoder is how it gets adjusted every two years, if required.

 

After my battery polarity issue that fried part of my transponder, the avionics shop suggested I pull it and send it in to check - turned out it was fine.

 

Anyway, good to know that this functionality is built into some modern PFD's - though as can be seen, troubleshooting and repair may be more problematical.

 

Caveat - unless Experimental, technically owners really can't do anything involving their transponders, encoders and the like - removal and adjustment included.

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How about an LSRM-A? I don't remember being told what we could not do in relation to some of these things.

Not sure.

 

I would think they could do removal and reinstallation. As far as repair, I think that takes some sort of avionics certification.

 

But, again, I'm guessing.

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While it is true that LSRM (properly rated) can perform maintenance on transponders and related systems, FAR parts 91.411 and 91.413 specify who can certify these systems as required for most VFR and all IFR operations. Removal and replacement of these components (Altimeter/ADC, encoder, and/or transponder) will most likely invalidate the certifications required by 91.411 and 91.413. To legally operate the aircraft in any conditions that required their use (transponders and integrated systems) would require re-certifying this equipment. This type of maintenance cannot be performed by and LRSM or A&P.

 

 

Doug Hereford

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Roger,

The relevant regulations apply to all US registered civil aircraft. Ref. 14 CFR parts 91.215, 91.217, 91.411, and 91.413. Advisory Circular 43-6C is also a good reference regarding maintenance on these systems.

 

The key detail in these regulatory requirements with regard to removal and replacement of equipment lies in the possibility of introduced error. The GTX330 transponder connector is fairly reliable, however where the FAA is concerned, they feel that removal and replacement of the rack mounted transponder almost always falls under the category of "possibility of induced error".Therefore, at a minimum, partial systems test is required to retain overall certification. Same goes for the encoder in most cases. These tests cannot be performed by mechanics or LSRM. The only parts that could be performed by a mechanic would be a static system leak test.

Replacement (with a different unit) of a standard barometric pressure altimeter also requires recertification of the integrated system to ensure accuracy of the altitude reported vs. altitude displayed with +- 125ft. tolerance over a sufficient number of test points (14 CFR part 43 app. E). Again, these tests cannot be performed by mechanics or LSRM.

 

Doug Hereford

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Those who have older CT's with steam gages might have the altitude digitizer that I have. It's a ACK altitude encoder and supplies input to my Garmin SL40 radio which allows it to display pressure altitude.

I have never seen pressure altitude on a SL40. Did you mean GTX327 transponder?

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From the skyview installation manual

 

SETUP MENU > SYSTEM SETUP > SERIAL PORT SETUP > SERIAL PORT x SETUP > SERIAL OUT DEVICE > ICARUS ALTITUDE 100ft OR ICARUS ALTITUDE 10ft

 

SETUP MENU > SYSTEM SETUP > AIRCRAFT INFORMATION > AIRCRAFT HEX CODE  > ACCEPT (button).

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