After the node had been switched off yesterday, everything is back to normal again today. Issues arose yesterday while swapping node transceivers. Already some time ago a Motorola MTM800E had arrived. Yesterday the moment had come to switch of the ‘normal’ MTM800 and fire up the MTM800E. But then it appeared that the audio signal in both directions didn’t pass the transceiver. Only the PTT circuit was fully functional.
The night was spent thinking and rethinking what was going on. The solution was found in the settings of the MTM800E. Using the CPS software the behavior of the accessory connector at the backside of the transceiver had to be changed (more details to follow). As that had been fixed and the radio passed incoming and outgoing audio again, I notieced a leak in RF signal. This resulted in a cellphone like hammering signal at the internet-side of the Echolink connection as soon as the outgoing audio of the transceiver disappeared.
This was caused by a sloppy connection between the transceiver’s antennaconnector and the bulkhead connector at the backside of the desk console. This caused RF to leak which was picked up by the incoming audio line of the Echolink interface. Because the bulkhead connector was mounted on a separate metal plate it could be removed easily. As a temporary solution now the antenna cable has been pulled into the desk console and directly plugged into the transceiver. The issue has been solved by this. As a permanent solution a new pigtail has been ordered, with an N bulkhead connector for the desk console and a BNC connector for the transceiver.