Here’s a batch of audio cables and stuff I built. Unfortunately I haven’t taken time to really dive deep in the measurements yet.
As to going unbalanced output to differential, RCA tip to + and RCA shell to -, BUT, to keep the - from becoming a large antenna, you will then need to separately ground the unbalanced DUT, and use the analyzer differential input to subtract out the difference between the DUT’s ground and the analyzer’s ground. While the analyzer has a fairly high impedance from the BNC shells to USB power from the computer, all analyzer BNC shells are solidly connected together, so if your generator output is driving an unbalanced input, you’ve already connected the grounds together. It’s all part of why unbalanced sucks.
Dale Shirk