Vintage Original 1950s Shure 520 High Impedance Dynamic Microphone

In 1961, Shure had pretty much settled on the winding size, keeping the impedance at somewhere near 1050 ohms. Over the past 5 or 6 years, Shure changed the appearance of the tags that were used on the shells. After the first tags that were the same green color as the shells, they changed the tags to a deeper sort of “Hunter Green”. The lettering was still embossed on the tag. Shure made a move from Chicago to Evanston, ILL sometime in 1956. It was during this period in time that the deep green colored tags were used. You will find them with both Chicago, and Evanston,ILL on them, which can help clue you in onto when a mic was made. I suspect that Shure started using the deeper green embossed tags shortly after 1950. A large majority of the CR tags are the deep green color rather than the same shade of green that the mic shell was painted. When Shure made the change of names from CR to CM, the tags changed again as well. The tag no longer had embossed lettering. They were a deep, sort of emerald green color with the same information on them as the old tags, with the model # and impedance stamped in the blank boxes.