Hi,
I am teaching myself in electronics and recently I have build a basic transimpedance amplifier. But when I am measuring ths output-signal with my oscilloscope, I also catch a lot of ambient noise/signals. So, I have build a quick-and-dirty box, which should protect my circuit under test from such external influences. As materials I have chosen tinplate (against E-fields) and layed it out with copper (against H-fields). Also it's working you can see from the picture the whole assembly is very cheesy, which is the reason why I want to build a better version of it:
The main design-improvements I have in mind already: to avoid any gaps between the lid and the bottom, either I will use finger stock or I will design a kind of flange so I can screw both parts together;
Where I need your advice:
- when the box is closed, I cannot use my normal probes from the oscilloscope anymore. So, I placed BNC-ports on the box-wall, and soldered a resistor and adjustable capacitor in parallel on it. From there, I am then running normal wires to the circuit under test (well, in the picture it's just the simple battery).
I am pretty sure, many people already have designed their own EMI-box and perhaps they could share some (low-cost) hints.
Thanks!