A friend of mine is having problems with a measurement signal he is getting from a Rogowski coil. When he changes the coaxial cable length the amplitude of the signal changes. It’s been a while since I’ve studied this type of thing but to me it sounded like an impedance mismatch issue and thought that I would suggest using a balun. Does this sound like a sensible solution? The Rogowski is a clever design but quite simply a single loop of sold aluminium with a very low inductance, around 1 x 10^-10H. The signal is going straight in to an integrator circuit, and from there in to a scope. I’d really appreciate any advice on the subject so I can help my friend out. Thanks.