I run six loops out of an SB-1203A patching panel (although that is not necessary) Loops 1,2 and 3 are remotely powered.(powered by modems with internal loop supplies.) 4,5 and  6 are powered by the SB-1203A. I can use them as test loops or key them with an RS-232 modem and a polar relay. The first four loops appear at  locations where I work on or use Teletypes.

I am trying to pull a wire to get the last two loops  over to the house, but it is very difficult to pull a new wire through a 100 foot buried plastic pipe that already has several wires in it and has a 90 degree bend near one end. I have not even gotten a snake though it yet.

Tom  N3CRK