Power Supplies, due to their Weight, are placed at the bottom of Racks (prevent tip overs / weight distribution). https://avitech.com.au/?page_id=366
The PDP-11/70 Maintenance and Installation Manual (EK-11070-MM-002) explains that the basic PDP-11/70 system components are located in a double cabinet as shown in Figure 1-1 of that manual. https://i0.wp.com/avitech.com.au/wp-content/uploads/2016/05/major-assemblies-fig-1-1.jpg greg > Date: Sat, 4 Dec 2021 19:28:01 -0800 > From: Marc Howard <cramc...@gmail.com> > To: "General Discussion: On-Topic Posts Only" <cctech@classiccmp.org> > Subject: Need picture of power supply mounted in 11/40 cabinet