Dear Graham, LF Group,

The problem with rope as an insulator is that, when it gets wet, its
dielectric properties will become poor, however good an insulator it is when
dry. I expect with the present relatively QRP levels at 500kHz, this will
just lead to somewhat increased antenna loss resistance. But with  more
power coming into use soon at 500k, heating of the wet rope may become a
problem. It certainly is on 136k - poor conductors/inslators in contact with
or close to the antenna conductor have a habit of melting or catching fire.
So would be a good idea to join the guy ropes to the mast via insulators.

If you are within reasonable distance of a fishing port, the braided twine
that chandlers sell for repairing nets, etc. is pretty good for
sun/weather/wear resistance, and a lot cheaper than the kevlar cord. The
main advantages of the kevlar stuff seem to be that it hardly stretches at
all under strain (if that is useful), and it is quite thin for its breaking
strain, which helps to make it less visible to disapproving neighbors and
the like. I have had some of  this guying a mast for several years now, and
it seems to be coping quite well with the elements

Cheers, Jim Moritz
73 de M0BMU