In article .com,
davidlaska writes

Phone company left me 500' of 4 strand telephone wire with a heavy
insulation that is rated tough enough where all you need to do is role
it out on the ground ( no burying or hanging or conduits needed). I
want to draw 12v dc at 0.2 amps (one fifth of a amp) over 200' and
want to calculate or know the voltage drop

The cable's 4 wire and you only want 2 (12v + and -), correct?

If you parallel up the cores to make 2 wires of 2 cores, that'll reduce
the resistance of the cable and thus the voltage drop.

I did this with a long run to some garden lights. With 2 wires, the
voltage drop made the lamps dim. Fortunately, I'd run 4-core 1.5mm^2
cable out to the lights (it was in my spares pile) and so was able to
reduce the voltage loss by doubling up the cores. This made the lamps
run at about normal brightness.