Performed some functional tests of the 7A16A, 7A18A, and 7A26 plug-ins and I have the results. When I get a new to me functional scope, or in this case plug-ins, there are certain basic criteria that I look at and if they pass I consider it “calibrated”. There is no way I can do a “by the book” calibration because I don't have the proper equipment and in reality unless there's been major repairs or some dimwit has been in there twiddling pots it really isn't necessary. The criteria I consider important are:
Vertical gain. Example: does a 0.5V p-p waveform appear as such?
Trigger. Does the waveform trigger and is it stable?
Compensation. 1KHz square wave flat with no peaking or rounding?.
High frequency test. Does a 1MHz and 10MHz square display accurately?
Sweep speed. Is it linear and accurate?
Trace quality. Bright and sharp focus?
In the case of these plug-ins only the first 4 apply. The sweep and trace are determined by the mainframe and the timebase plug-in. Here's my test set up. The Feel Tech function generator is for the 1KHz square wave. The Heath IG-4244 Scope Calibrator is for the 1MHz and 10MHz square. The 2465 is powered up and on standby in case something don't look right.
![](https://imagizer.imageshack.com/v2/xq90/923/71V6H8.jpg)
So how did these plug-ins perform?
Vertical gain: All 3 plug-ins were dead nuts.
Trigger: Solid Trigger on all 3.
Compensation: The 7A18A and 7A26 are perfect. The 7A16A has both peaking and roll off issues. While attempting to adjust it the trace is dancing around again. I guess I'm going to have to pull this attenuator assembly apart and give it a more extensive cleaning. Luckily it's easy to get to. Into the project cue.
High frequency test: Both the 7A18A and 7A26 are OK. The 7A16A because of the problems above shows extensive peaking at high frequencies.
This is MY rabbit hole.
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As soon as Inverted18650 gets back to me with a shipping cost I'm going to have a 7704A to play with.
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