The antenna should be placed as high as possible with as few obstructions as possible. It may be installed either vertically or horizontally. We suggest testing the antenna system in several locations before permanently installing the unit. We have heard of installations in attics, in a second story room, even on bed posts. The metal siding of some buildings make installation tricky.
Metal siding to radio waves is like tank amour to bullets.
The metal siding acts as a ground to radio waves and will generally shield the building from radio waves both inside and out. Often to get service outside of the building with your cordless phone, you have to place the antenna outside. The cordless phone will continue to work on the inside for the building that has the base unit. We do NOT recommend splicing the cable. Longer cables often result in such a great signal loss in the cable that the additional antenna height loses its effect.