If you're talking about a receiving antenna, there's really little loss
in using a piece of line tied directly to the antenna wire to maintain
tension.

But consider, that the line will be in contact with other
infrastructure. A tree, a pole. The house, or garage.....whatever you
use to support the block. And while dry, that may be no issue, when wet,
there's enough conductivity to take a nearby static strike up directly
into your front end. May not be the best result.

Using an egg insulator between the line and the wire of your antenna
allows that extra bit of isolation that may save your input. It also
allows a more secure mounting of the antenna, and attachment to your
tensioning line because the mechanical strain is almost entirely borne
by the insulator. Further, if correctly installed, the egg is, itself,
in compression, not tension, so even if damaged, there isn't an
immediate danger of release.

For a receiving antenna, there are few differences in performance. But
there are a few benefits to using an insulator mechanically. And there
may be benefits if there are static issues at your listening post.

A good quality ceramic egg is the better option. Both mechanically and
electrically, and will deteriorate less over time, when exposed to the
elements.



I have a skirt tuned multiband HF vertical, made entirely of aluminum
and plastic. It requires no guys, but I use them anyway due to hurricane
force winds some times. I have 4 [ea] Dacron antenna ropes, tied
directly to the radiating metal of the upper half of the vertical dipole
at about 22 feet AGL. The ropes are at a 45 degree angle and tied to
stakes in the ground.

Wet ropes, as described above, make no difference. Inductively coupled
energy from nearby lightning strikes will get directly into your
transmission line, regardless of your clean eggs. That's why you use Arc
Plugs or something similar.

http://www.mfjenterprises.com/pictures/MFJ-270.jpg