GPS on Metro 3
 

Has anyone worked on a GPS installation on the Metro 3? It doesn't find any satellites, after swapping receivers there was no change. After checking the wiring with both ends of the coax in the air, the core appears shorted to the bleed. Does anyone know if there is anything in between the antenna and the receiver, ie filters etc? I realize its an airframe specific install most probably and couldnt find paperwork regarding the install so Im just shooting the question...

I think you mean that the core is shorted to the shield (outer braid) in the coax cable. The cable probably has been crushed in the run some where, you will have to follow thw cable to find out where. It will most likely need to have the cable replaced.

This is not Metro specific, as the information applies to all aircraft and radios.

You could try connecting a known good cable ( just make one up and temporarily connect it) and see if the GPS works.

Strand of wire from the shield to center conductor will short out the signal.

Thanks for the input guys, that was what I initially suspected, but I was asking if there was possibly anything in between the antenna and the receiver...
There did appear to be a short between the core and shield though, thanks again