Does any one know if a two wire cable with one ground around both wires is a issue ? Some one suggested that could cause feedback in a effects loop and both the send and return wires should surrounded by a ground wire of their own ? is using a Mic cable with a trs plug ok? Thanks
Don't overthink this...
By definition, the TRS jack in the effects loop is signal out, signal return, and ground.
There are any number of inexpensive TRS->TS/TS cables available from your favorite online retailer(s), though I haven't seen one with a right angle TRS plug (but I also haven't look very hard). There are more expensive ones available from some of the "legacy" folks as well of course along with breakout boxes that passively split the TRS cable from your guitar into a pair of TS jacks so you can use regular TS cables to and from your effects.
They're trivially easy to make yourself as well.