Quote:
Originally Posted by wa2ise
Thing is, I don't see anything on this "scope vertical" output. Looking at the machine's schematic in the manual, I can see that the scope's 50 ohm impedance would not play nice with the megohm range mixing circuits in the machine. So that's one issue to resolve.
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Some progress: I found an old chip, an LH0032c high frequency op-amp driver chip. I found its data sheet, and wired it up as a unity gain circuit. High input impedance, and low output impedance, adding a 50 ohm resistor as source impedance to match the cable and scope load (and the resistor provides some short circuit protection). Seems to work for me. Some of the RF generator's RF leaks into it (but this thing is not a lab grade instrument). But I can use this leakage to my advantage, as this leakage will interact with the marker generator. I can see a dip when the generator and marker frequencies coincide. And as my scope has two vertical inputs, I can view the output of the device under test on one channel, and see the marker dip on the other channel.
Ideally I'd want a sweep generator/ spectrum analyzer, but that's not in my budget...
