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Old 14th Apr 2018, 3:05 pm   #14
Dave Moll
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Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 3,944
Default Re: Ambassador/Senator external extension adaptor

Returning to the question of internal calls from the external extension, some further digging has come up with an Ambassador ESS system manual in which my conundrum is solved. Buried in the text on page 3.16 is a paragraph reading as follows: Mounted on the circuit board contained within the Adaptor is a "link" type switch SW2. This switch must be OPEN..

I had noticed this switch and wondered whether it served this sort of purpose, but didn't wish to alter it without the appropriate confirmation of its function. Presumably, the equivalent text in the Senator system manual (which I haven't managed to track down) says that this switch must be CLOSED - as the one on my unit is. Before I next fire up my demo setup, I shall open this switch, which should make the external extension work on the Ambassador as described, rather than using the kludge I described earlier.

And by the way, the manual also confirms OF's supposition about "C wire" signalling.
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