NTE5c & VDSL Service Specific FacePlate modification in 2024

Right. So have got my hands on a current Openreach NTE5c Master Socket, fitted with an Mk 4 VDSL filtered "SSFP", as sold by our old pal Jeff for under a tenner.

Objective is to modify the Pressac made VDSL filter circuit board in accordance with the instructions noted on the A&A support website, to cater for Voice Re-Injection (VRI).

Pressac-made circuit board in the Openreach V4 SSSP referred in A&A blog aka P66_10368_00 c. Q4 2017

Pressac-made circuit board in the current Openreach V4 SSFP (from Amazon) aka P66_10368_08 c. Q1 2024

Looks like Pressac have made modifications over the various iterations, from 00 to 08 of these things, and removed and added some bits and bobs:

- (removed) PS1 {is this a spark gap?}
- (removed) inductor, L4
- (added) resistor R5 (-> perhaps in lieu of taking out L4 & PS1?....I probably could trace out the reverse into a circuit diagram 🤯)

The other (spark gap?) PS2 (required to remove for VRI) is still there, but in a different position on the board. R6 which is optional to be removed for VRI is still there.

Anyhow I'm sure snipping out just PS2 (and R6 to take out the ring capacitor) will be what's needed for VRI...

Edited by Pheasant (Thu 28-Nov-24 21:22:47)

Google AI tells me the PS2 labelled passive is actually "a resettable polyswitch fuse, also known as a polymeric positive temperature coefficient (PPTC) device, is a passive electronic component that protects circuits from overcurrent faults. It's also known as a multifuse or polyfuse". Yeah cheers for that Sergey!

So I guess that's where the PS nomenclature comes from i.e PolySwitch. The only other reference I could find was from a very early LJU type master socket fitted with a SP1 'spark gap' which morphed 40+ odd years later into the PS1 'poly switch' in the NTE5 family master socket.

Just rambling now 😂

Edited by Pheasant (Thu 28-Nov-24 22:14:22)