[SOC] SOC - Feedline question

[thom2 at att.net]

 Hi gang,
  It's certainly nice to be able to go someplace with a question like this.

  I have about 50 feet of 450 ohm (I think) ladder line.  I need about 75 to 100 feet for the antenna I'm planning (an inverted V).  My questions are:

    1)  Can I splice two pieces together for the feedline?

    2)  Is there any way to know that the piece I have is 450 ohms (I'm kinda assuming it is).

Anyway, thanks for providing a forum where I don't feel too embarrassed to ask questions of this nature (i.e. dumb).
Tom
WB2QDG