As I wrote once - in late 80ties I worked in a lab which messed with 1/f noise measurements. Within my diploma work I created a measurement chamber for the LNA and the samples with all the necessary batteries. The result - see below. Inside that box we had an additional copper foil inner box. There is a single 5mm dia hole for the coax.
What is funny a friend of mine, who works there at university, showed to me my decades old box yesterday - they found it while they did a cleanup of the labs, with an intention to carry it to scrapyard..
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Thus I've shot a couple of pictures - for a record - the box weights some 25-30kg (an estimate), a little bit rusty here and there, but still in an excellent condition..