Running a static tube from the altimeter to ?

you probably have a 2nd unit in the static line, your altitude encoder, but like a altimeter, if the static line is leaking, you could be reading cabin pressure, but it will not prevent the encoder from working, if they are not reading mode C, then either the encoder went out, or portion of the transponder.

This post/response is almost a year old. Any update to your altimeter needle dancing between 100 and 200 ft? My altimeter is doing this as well. I have been researching what the cause is. Tear/hole in the line, water, something blocking the line. And for that matter, I did a cross country to check my transponder with ATC. They could not receive my altitude. I have a Bendix KY76 TSO. Should be sending the altitude. If the static line is bad, sending error altitude heights to the altimeter...does that interfere with the transponder's job.

Did that, but will check again. Perhaps the line is loose or is damaged in some way. Thanks for the reply...WDB

My '46 415c s/n 1069 came with a static port as part of the pitot on the wing. If I lift the aileron, I can see two tubes. One is ram air for the ASI, the other is static. Perhaps yours is just disconnected? If yours is disconnected at the instrument, then your altimeter is showing your altitude based on your cabin pressure. It might also be disconnected at the joint between the wing outer panel and the center section, where the tubes are spliced with some flexible tubing. If it is disconnected there, then your altitude is base on the air pressure inside the wing structure.

My altimeter needle wiggles in flight like moving from 100 to 200 ft. I am told to install a static tube. I did install one in the RV 7 on the body of the plane. Would that work in the ercoupe ?