Left cable now works fine, if the cable is installed with the free end in a particular direction. Really need to write down somewhere which way it is.
Decided the Winglets needed to match, so cut an access hole for the right bellhorn to match the left, and opened both up to 20mm.
Clean up a bit around the cable conduit, and reinstall, noting the same interference as on the left. F*&k!!! See note above. I'm not bothered for the moment.
Terminated the antenna coax with a BNC connector and hooked one wing to my base station and one to a hand-held. Didn't work well which worried me for a minute, then I realised that with the wings stored leading edge down next to each other the radiation patterns avoid each other. I tested each wing in turn with the base station antenna laid alongside the Winglet and achieve communication.
