My old Sky+ box had a 9V RF output that powered my 2 way satellite distribution amplifier directly in the loft. It allowed me to watch TV in two more bedrooms upstairs.
Recently I had the Sky+ box upgraded and the 9V output is now too weak to provide the same service.
The 2 way amp (http://www.philex.com/catalogue/product/?id=901&cat=1069) has an external DC port so I can power it from the mains, but of course the adapter did not come with it in the first place. Here's a pic:
I rang them this afternoon and they informed me they don't even sell the adapter anymore! Anyway I thought it shouldn't be too difficult in sourcing a 12V DC adapter for this device until I saw the connection on it.
It looks (and I'm 99.9% sure I've seen this written somewhere else online) that the device takes a 3.5mm audio plug! Not a normal power barrel.
I'm handy enough with soldering but I'm just not sure if what I think I can do is acceptable...
Can I take an old 12V DC adapter I have lying around here, and snip off the power tip at the end, strip back the wire and solder it to one of the many many 3.5 audio jacks I have here currently connected to various cables?
How do I check I get the polarity correct? Is there an easier way? Am I missing anything?