Altitude encoder

[davidjohnstone]

We are now test flying our RV9A & have had a problem with the Altitude encoder & the link to the Becker Transponder.

The Becker is getting the information from the Mode C box but stops showing heights above about 2500 ft

Is ther something in the set up that we have done wrong ?

David Johnstone RV9A G-EGBS

 

[dynonsupport]

How much higher than 2500 did you go and still see it stuck at 2500? Also, are you sure the reported altitude was changing at all below 2500 feet?

If you have the encoder converter module, the only thing to make sure of is that you have the format set to 1 under the SETUP>ALTENC menu. If that's the case, it should just work, as long as everything is wired alright.

Of course, there could be something up with the encoder converter, the wiring going to/from it, or the transponder itself.

If you have the software set up right, I'd take a fresh look at all of the wires going too/from the encoder converter.

 

[davidjohnstone]

The encoder worked perfectly all the way upto 2500 ft then stopped. We continued on upto 3500 ft with no change to the displayed encoder

 

[dynonsupport]

If it worked from 0-2500 feet, then the data is getting from the EFIS to the encoder converter, and the converter is also working. Only one bit on the output changes to go from 2500-2600, and this bit also changed from 1900-2000.

The encoder working at all and then getting stuck at one altitude doesn't really make any sense to us. The only thing I could think of is that the converter somehow locked up- did it begin working again as you descended below 2500?

 

[davidjohnstone]

If it worked from 0-2500 feet, then the data is getting from the EFIS to the encoder converter, and the converter is also working. Only one bit on the output changes to go from 2500-2600, and this bit also changed from 1900-2000.

The encoder working at all and then getting stuck at one altitude doesn't really make any sense to us. The only thing I could think of is that the converter somehow locked up- did it begin working again as you descended below 2500?

Yes it worked normally on the way down & was at the right height on the ground.

 

[dynonsupport]

So is it doing this consistently, or was this a one-time occurance?

 

[davidjohnstone]

So is it doing this consistently, or was this a one-time occurance?

This was the first test flight with the encoder. We have been back through the wiring & think that one wire might have been connected to the wrong pin. No 4 should have been No 3 will advise when we have test flown.