Thanks everyone. Here's a bit more detail.
I do a lot of audio amp testing. Some amps have a single ended output and some are balanced. So if I'm, say, looking to see where they clip using my scope across the load resistors I need to take care about that unbalanced scope input.
I do most of my bench testing (all the simple 'triage' stuff anyway) with a 400Hz oscillator. I have big 8Ω non-inductive loads. I want to use transformers to sniff the current in these loads so my scopes' unbalanced input is isolated from the DUT.
I would hook the transformer secondaries directly to the scope inputs; no shunt or other load would be added. The 8Ω loads and associated transformer would be mounted onto a small piece of wood and permanently paired to each other.
This is solely to see the shape of the waveform, I have nice bench meters across the loads to tell me what the voltage is. I do not need any amplitude accuracy from the scope. Just need to see that 400Hz sine wave, and see when it flattens out.
These transformers are rated for 400Hz, so... why wouldn't this work? I think it should be a decent, cheap solution to one (and only one) measurement issue. Right?
Thanks again.