See also Lightning Protection for the Amateur Radio Station -- Part 2
QST July 2002, pp. 48-52http://www.arrl.org/files/file/Technology/tis/info/pdf/0207048.pdf
There are commercial protectors available for open wire line, and some homebrew solutions,* but I think I'd choose one of these tactics
- Throw the open wire line out of the house and ground it below the feed point when not in use.
- Put the balanced tuner on the ground outdoors some distance from the house, making for a practical ladder line/OWL run between antenna and tuner. Put open wire line protectors where the ladder line enters the tuner (might be a waste of time). Ground the tuner itself well. Now no ladder line enters your house, just 50 ohm coax and control lines, which you put the same protectors on in your entry box as your other coax and control cables.
I would never want ladder line/OWL to enter the house in a thunderstorm. In the first tactic, a direct strike will turn both the dipole and feed line into a spray of hot copper and plasma. In the second tactic, the same thing will happen and perhaps kill your tuner, but hopefully not kill your house and shack.
If you live in a place with dry vegetation or much lighting, I'd take down the whole antenna whenever not operating.
*: Note that when you tune a balanced feed line across many bands on full power, you could have some pretty high voltages where the ladder line enters the tuner. This could easily surpass the clamping voltage of commercial protectors. Homebrew alternatives include air gaps created by grounded cylinders around each lead of the feed line.