I have acquired one of the above adaptors, which I have now connected up to an Ambassador CCU is described on
Bob Freshwater's site.
Nearly everything is working as described:
dialling 81 (loop dis.) etc from the external extension gives access to an external line
an incoming call rings the external extension as long as "remote answering" on the adaptor is selected (button illuminated)
I can call the external extension from an Ambassador terminal connected to another extension
... but I cannot identify how to call the other extension from the external one. The above-mentioned site doesn't include this function under "External Extension Facilities", but merely says that "The facilities of an external extension are similar to those [of a normal extension]" with the exception of those described. As inter-extension calls on an Ambassador system are initiated by pressing keys on the extension stations (which are not present on an external extension), this function is clearly not similar.
Is this function only available on a Senator (where inter-extension calls are initiated by dialling the extension number)?