flexible 25 ohm coaxial

I want to constuct a transmission line transformer with coaxial,
but it seem that the coaxial of 25ohm is hard to buy.
Can anyone tell me where to buy?
regards

Maybe semi-rigid is flexible enough.

http://www.micro-coax.com/pages/prod...Than50ohms.asp

Two 50 ohm lines, connected in parallel, and quarter wave long each will look like a single 25 ohm transmisson line that is a quarter wave long.

Same trick applies for stubs. If you need a 20 ohms stub that is quarter wave long, use two stubs that are 40 ohms, connecting to the same point.

Thanks for all,
But, I want to a flexible coaxial cable of 25 ohm

Why do you need a 25 ohm coaxial cable? What is your application?

The goal of my project is to build a FM band power amplifier.