Diameter of dc female jack pin?

Hi @kurtnorgren

I don't know the answer but if you don't get a more relevant answer, take the clock's AC/DC power adapter to an electronics spare parts store and then check what DC socket it fits into.

The most common plugs/sockets used that are very similar in barrel/centre pin size are a D5 size (5.5mm x 2.1mm) and a D6 size (5.5mm x 2.5mm). There's also a D4 (5.5mm x 1.7mm) as well, just to confuse the issue. There are others but they are noticeably different in their diameter than the previous ones mentioned

It is hard to visually tell the difference between a D5 and D6 plug and also mechanically as well.

There is a test however that helps to determine which is the size. A 5.5 x 2.1mm plug will fit into a 5.5 x 2.5 socket but the centre pin will be a loose fit i.e. plug's centre pin is 0.4mm smaller than the centre connector ring in the socket and there may be intermittent no power problems. A 5.5 x 2.5 plug will not fit into a 5.5.x 2.1 socket i.e. plug's centre pin is 0.4mm too big