I'm in the UK. I want to record my landline phone calls.
I once made a crude device which had a transformer (don't know its spec). A pair of wires from one side of the transformer went into the telephone wall socket and a pair of wires on the other side of the transformer went to a jack plug which goes into my recorder. There's a potentiometer adjusts the output level.
It kind of works but not very well and I get too much hum.
What would be a proper circuit to follow?
Even better, is there a non-expensive recording adapter I can buy in the UK which plugs into the phone wall socket?
This is posted to uk.telecom and to some elctronics groups.