When measuring loop gain and phase with the method presented by the late R.David Middlebrook it is helpful to use a dual channel pre-amplifier with a selectable output, ch. 1, ch2, and ch1 - ch2. Middlebrook's paper are on the www.venable.com site.
I would like to have an updated version of the 1A1 preamplifier. The main problem with the 1A1 is finding a power unit, such as the 127. I do not want to get a 500 series scope. I have a 2465A with ch. 2 output but not the vertical output. How can I change the Ch.2 output to a vertical output?
If I find a 5003 power unit and a 5000 series deal trace module would I be able to get the vertical output and if so would it need buffering?