XPNDR ERROR

[RAS]

I am still new to this panel and occasionally I notice that we get a Message: "XPNDR ERROR" that is greyed out. I checked "Transponder Warnings" and it indicates: "TX Power Low (156)." I searched this forum, the WWW and the manual the best I could but I am not able to find an answer or an index. Towers and Flight Following have never indicated that there is a problem and as far as we can tell, there is no problem. I performed the B/U BATT TEST today. Thank you in advance for assistance/resources you are able to provide.

 

[airguy]

Likely you don't have enough voltage at the transponder - could be undersize wires, or a bad connection on either power or ground.

 

[GKC Aviation]

I just had this on a customers Dynon transponder.
It's not the power in to the transponder, it's the power out (Transmit power)
I replaced the coax and the antenna to test, but it ended up being the transponder itself, which Dynon replaced under warranty.'
You can upload the log files to Dynon, support are most helpful.

 

[RAS]

Thank you for the reply GKC. I just submitted a ticket. I will report back to this thread once we have it figured out/corrected.

 

[RAS]

As you stated GKC, Dynon was quick to reply to our ticket. This was their reply:

TX Power Low indicates the transponder is running in a low power mode. It is typically an antenna or coax issue that is causing it to do that. Take a look at the coax and antenna, particularly the BNC connectors on the coax. The pin must be about even with the surrounding part of the connector body. It is also possible the problem is the transponder itself, be we rarely find that to be the case.

We are reaching out to the gentleman who installed the avionics. I will report back when we have resolved the matter.

 

[Rhino]

Absent water intrusion and corrosion, antennas don't fail very often. I'd lean toward the cables/connectors, but the antenna is usually easier to check first. I also highly recommend RG400 cable or better. Too many builders install cheap, crappy antenna cables, and pay the price for it later.

 

[GKC Aviation]

Absent water intrusion and corrosion, antennas don't fail very often. I'd lean toward the cables/connectors, but the antenna is usually easier to check first. I also highly recommend RG400 cable or better. Too many builders install cheap, crappy antenna cables, and pay the price for it later.

I had a cow chew a transponder antenna off a C210 recently

 

[Rhino]

I had a cow chew a transponder antenna off a C210 recently

It's a little known fact that Mode C stands for Mode Cow.

 

[airguy]

I had a cow chew a transponder antenna off a C210 recently

Rename the cow "Ribeye".