Opek CX5

Issues with Opek CX5 coaxial antenna switch

Very strange effect when connected into the antenna system.

Noise and other weird effects. The main one that had me going for a bit was the only way I could get the noise to lower was by holding the PL259 plug!

Measuring between the shield of the coax sockets it was reading anything between 3 and 12 ohms. Not 0 as you would expect.

Inside no connections have been made for the earth/shield side so totally reliant on the connection through the metal casing. Removed one of the screws from the socket and saw that it was trying get a connection through the paint work of the case. This explained the resistance that was being measured.

The only thing to do is scrape off the paint around one screw hole on each socket and add a serrated washer.

Once that was done, near enough 0 ohms between the sockets, normal service was resumed.

Don't forget to do the same to the case screw.