Correct Size Knock Out Hole Punches

[ZeusMC]

Hi Guys

Re: tube socket drawings:
Some sockets have a stamped metal bracket that makes the mounting orientation obvious, then there is only one dimension that you need to match with the socket. Make sure the socket is not so loose in the large hole that the bolt holes fall onto the circumference, or worse, into the hole itself.

Sockets that have a bracket that allows top or bottom mourning may have one or two dimensions to note, but most often it is a single dimension.

When there is an option for top/bottom it is mostly aesthetic which you choose. The tube insertion force is borne by the bolt and nut or by the chassis, with the extraction force borne in symmetric fashion.Sockets with tube shields are typically top-mount. Bottom-mount's only advantage is in bulk removal of the circuitry and wiring to the socket, assuming everything must go. Otherwise, there is no inherent advantage to either top/bottom mounting.

Re: solder:
Why would you buy rosin-free solder? The rosin helps to clean the surfaces that are meant t accept the solder.