wrote:
On Sunday, 5 January 2020 20:43:25 UTC, Robin wrote:
I visited a HH5 today. FWIW PSU was P/N 19118836, model no.
S018RM1200150, "for use with BT Home Hub 4 & 5 Type A"; my cheap
Workzone caliper gauge showed an external barrel diameter of 5.44mm; and
measured the diameter of a screwdriver which was a sloppy fit inside as
2.88mm.

Thank you. So I definately need a pin hole bigger than 2.1mm.

I know this is DIY and all, but have you thought about just buying the
appropriate PSU:
https://www.ebay.co.uk/itm/BT-home-h...A/401997917212
https://www.ebay.co.uk/itm/Genuine-B...y/163959541491
or less for a full HH5 (can't quite read the PSU writing - might be a type B):
https://www.ebay.co.uk/itm/BT-68343-...r/113919449125

You can cut the cable off if you want to power it from something other than
the mains.

Theo