Eh, 1999 was right when the split happened, so regardless of the label, it was still basically an HP product at the time. Still, that doesn't help you much; the

Eh, 1999 was right when the split happened, so regardless of the label, it was still basically an HP product at the time. Still, that doesn't help you much; the 16505A only worked with the 16500 series analyzer. There was a 16700, IIRC, that was basically an 16500C with an integrated 16505A, but that doesn't help you much.