oops. found this open in a tab. looks like i forgot to ever post it
the whole product category of "radio scanner" is a thing i don't really understand, but then i've never really been radiobrained so what do i know. anyway, the idea is, i guess, that you literally. scan. like, the box sits there and flips through frequencies you've deemed interesting at regular intervals, or you can hit a button to pick a preset. you program in like, local police and fire channels. whatever scanner people like
modern ones are straightforward, obvious digital devices. you program in known frequencies or you just let em scan a whole range continuously. nothing to it. but it didn't use to be like that.
radios used to not be able to just tune to Any Old Frequency. at one point in time, if you wanted to change the channels on your scanner, you had to open a little hatch and pull quartz oscillators out of a little crystal bank. one per channel. absurd. things didn't get much better until Digital happened, so in between there were some utterly Batshit solutions
the first thing above is an SBE Optiscan. you program your frequencies by peeling little stickers off of a clear plastic card to form numbers in some kind of binary. inside, a bank of photocells reads the card. i think this was in the 70s
the second pic is the accessories for the WHAMO 10. i think it was even earlier. those things on the left are metal "combs." you program this one in binary as well, by breaking off the tines. it comes with a worksheet and a comb code booklet.
