[TowerTalk] Feedline for a new tower

[Matt Frey]

Looking for suggestions of what feedline to use on the 70' tower. HF beam
antenna that rotates.

Total length of feedline to the radios would be 100'.

Have been told to use LMR400 or RG123.  Need to transition to a more
flexible cable at top of the tower for the rotation?

Should ground the coax at top of the tower and at the surge arrestors at
the house wall 5 feet away?

Thanks for any comments,

73,
 Matt AA3RO