Found a pair of these at my local salvage yard for $4 a pop. Decided to take them home and see if they still worked. While they have some shoddy re-wiring to convert them to RCA outputs (one goes RCA female and one goes RCA male

), they surprisingly do indeed still functions as mics, both when run into my DR-40 set to "MIC" as well as an input into my small bass amp (though I think the level wasn't hot enough to come through aside from when I was speaking directly into the mic). Side note: how hard would it be to rewire these back to 1/4" for someone with no previous soldering/wiring background? Will snap a picture of the specific state of the wiring tomorrow, but it looks like the original wiring was cut close to the original 1/4" plug and simply rebound to the new RCA ones.
There’s almost nothing mentioned of these mics online, and only a single show using them that I could find on LMA. I have uncovered that they are electret condenser mics with a frequency response of 40 Hz-15000 kHz, which I know is quite limiting in terms of concert recordings.
Not expecting any worthwhile concert pulls to come out of them, but I'm interested in learning more about them. Anyone familiar with these, or have any idea about their history or intended use? Thinking they may be useful for home simple home recording.
https://i.ebayimg.com/images/g/3BgAAOSw5jpZh5c7/s-l1600.jpg(not my image)