(Author: David/KD4CLJ)

The SPA500S is a sidecar that allows you to add speed-dial buttons to your phone.

Sometimes, apparently, if you get a used one they don't always come with a cable.

When I finally got one WITH a cable, I stuck the auxiliary cable in my Palidin Cable Checker - It's an RJ12 - 6pin connection, and the the pinout is..

Pinout of P/N 3522-06205001R - Cable used between phone and sidecar, or sidecar and sidecar

1—–x
2—–7
3—–6
4—–5
5—–4
6—–3
7—–2
8—–x