This is often caused by overtighting the connector on these antenna’s which causes the center pin in the connector to be forced through the printed circuit board causing an intermittent radalt fault.
Or moisture inside the connector…..
ref. (MT 34-038)
Perform a Rad.alt receiver transmitter read out, if you find ‘EM’ or ‘EN’ faults these are related to the antenna’s.
EM = emmiter antenna.
EN = receiver antenna.
(ref fim 34-33 task 801).
Replace the corrosponding antenna will solve the problem.
These connectors are often found to be torqued to high, straight from the factory.
These are supposed to be hand tight only..!
Don’t overtighten these connectors to prevent moisture ingress.
Thanks to Richard E. for this input.