You've got to rough up the end of the cable with sand paper, enough to remove the gold coating where you want to solder. I also like to use a drill bit to rough up the inside of the brass coupler too. After that, clean the parts with a little alchohol or brake clean. I use 60/40 rosin core solder, silver is good but you really dont need it in my opinion. Silver solder is harder to work with also. I also like to use a little flux, I fill the brass peice with it then push the cable in. Clean off any excess with a towel and alchohol. Where theres flux, solder will find it so make sure its not covered in it... But it makse for a nice clean strong joint.
Now the soldering iron, if the tip is all oxidized and dirty it wont work. Clean the tip with a wire brush or file, dip the end in some flux and tin the end so the solder sticks, not just sits in a ball on top.
Fixture the cable horizontally on something so you can use two hands (small vice, whatever works). Place the soldering tip (clean and tinned tip) at the far end of the brass coupler, (near the threads) and hold your solder at the other end and wait for it to melt/ get sucked into the joint. The solder will go to the heat. Keep dabbing it until its full and makes a nice little fillet between the coupler and cable. Let it cool and your good to go.
Sorry for writing a book but that should pretty much cover it lol... hope it helps.
Brian
