Ahh very nice! I have an NOS version from 1984 and a used version from 1980. The NOS '84 one is a gray 120V one and the used one from 1980 is a gray 120-277V one. The easiest way to see if they're used or not is to see if there's an imprint in the gasket on the bottom. The gasket will be a little compressed on one half. If the gasket looks perfect then it's NOS!
Hmm are they imprints like a circular imprint that looks as if they were installed? They look used to me. My 1980 Fisher Pierce unit still looks shiney but it's used. I guess in the 80s they used a nice quality plastic. My 1977 FP is discolored though. The Ripleys almost always discolored though. They didn't stay pretty for too long lol.
Ahh since it has the socket imprint I guess they're used PCs. I'm surprised the plastic held up that well though. Normally the plastic would either dull or yellow.
yeah PCs are really random with their plastic quality lol. I guess it could depend on if the PC is in the sun all day or if it's under trees or a building canopy.
True, I was thinking t might not have been used that much since the contacts on the bottom are still shiny. The plastic is quite brittle though so I don't think I should open it up.
Yeah some of my PCs look really ratty yet have shiney like-new copper contacts while some NOS PCs have dingy brass contacts. Pretty random lol. Seems like these style Fisher Pierces held up well over the years besides there being an issue with the window falling out since it's glued in from the outside, which seems like an obvious design flaw but i guess at the time to them, they thought it was modern lol. In the 90s when Pacific Scientifc bought Fisher Pierce from Sigma Instruments, they reverted back to the inside snap-in window and started using soft plastic. The snap on Fisher Pierce PCs with the hard plastic seem impossible to open. The 90s and later soft plastic ones open with relatively little effort though. The early 70s and before FPs and the pre-2000-ish Ripleys and all DTLs have screws which makes them easy to open yet secure when you don't want them open (as long as you don't overtighten the screws and strip the threads in the cover lol)