This project shows a simple and well polished implementation of a differential-to-single-ended preamplifier, which allows a differential signal to be probed and fed to an oscilloscope via a BNC cable.

[Christer Weinigel] needed to get some measurements of a differential clock signal that ... bandwidth and most off-the-rack probes are single-ended, that is they’re referenced to ground.

see the entire Low-Noise Amplifier (Single-ended cascode ... 1.56 to 1.61 GHz low noise amplifier with 27.5dB gain Low-Noise Low-Offset RR Out Fully Differential OPAMP ...