Here's my method to make a neat through the wall twin lead or OWL
feedthrough:
Materials: 3/4 inch or larger PVC pipe, 2 PVC end caps preferably with
flat ends,
2 lengths of 6-32 threaded brass rod (McMaster Carr) or True Value,
6-32 nuts and washers, RTV.
Cut the PVC pipe = the wall thickness + about 1 inch.
Drill and tap one end cap for the rods and drill 6-32 clearance holes
in the other cap. I used about 5/8 inch spacing.
Cut the rods about 2 or 3 in. longer than the pipe.
Drill a pilot hole from the inside wall through the outside with a long
masonry drill (use a stud finder to miss the studs). Use a 1 inch
spade style wood bit to bore a hole first through the inside wall and
then through the outside stucco. I was surprised at how well the wood
bit worked.
The rest of the story is pretty obvious. I'd use RTV rather than PVC
cement so that the assembly can later be pulled apart if necessary.
73, John, KU6X