[TenTec] OT 75 Ohm twin feeder

[Stuart Rohre]

I would take that ARRL handbook write up with a grain of salt.  In the day 
they wrote that, zip cord had rubber; or other colored insulations that 
could contain metallic dyes that would increase loss.

Today's clear vinyl might not be as lossy.  PVC is higher loss than 
polystyrene plastics, but might be tolerable in zip cord.  There are many 
colors of zip cord, and you would have to strip off some insulation and test 
insulation alone, (no wire!) , in a microwave with a cup of water.  If it 
does not heat up by the time the water boils, the loss is very low in that 
insulation.

-Stuart Rohre
K5KVH