The RCA 77 went through numerous changes and permutations during its 30+ years in production that started back around 1932 and finally ended around 1967, when it was replaced by the BK-11. Surviving examples of the RCA 77 routinely sell for over $1000 on eBay nowadays. But wait a minute... why are we talking about the RCA 77 microphone, when our example here is a Calrad 500-C?
I'm not going to go into the technical details about ribbon microphones like the RCA 77, because a quick internet search will turn up more than you'd ever want to know about them. Suffice it to say here that ribbon microphones have long been considered to produce the most natural and highest quality sound you can get from a microphone. The downside to all this greatness is that ribbon microphones are very fragile, very expensive and very big.
In its day, the RCA 77 was considered the best microphone around, and was the one to use if you were after that rich, syrupy sound (think Bing Crosby) that only a high-quality ribbon microphone could provide. Considering its position in recording history, it's not hard to see how the RCA 77 would be sought-after by collectors nowadays. But since its performance is still considered just as fantastic nowadays as it was fifty years ago, sound engineers and recording studios are also out there looking for them!
The RCA 77 grew to become so synonymous with the broadcasting and recording industry that nowadays you can even see dummy versions of the microphone on the desks of Larry King and Dave Letterman.
The point I'm trying to convey to you here is that the RCA 77 is an institution, and where you have an institution, you very often have the copycats. Back in the 1950's, many companies, primarily Japanese, were pumping out their own versions of the RCA 77. Of course, these manufacturers weren't actually trying to compete with the 77 on any level, they just knew that people were really grooving on the RCA 77's pill 'look' (so named because it literally looks like a big pill,) and wanted to produce smaller and cheaper versions that would appeal to folks who wanted one to use at home, or maybe just have one to dress up their desk. To give you an idea of the plethora of copycats that were spawned after the RCA 77's look, just consider these:
Akrad M-102, Aiwa Model M-18, Aiwa Model DM-17, Aiwa Model VM-12, AMD Model 38-600, Argonne Model AR-57, Argonne Model AR-309, Armaco Model M8D, Calrad Model DM-15, Calrad Model VM-12, Claricon Model 38-600, Crown Model MC-80, Densei Model M-36, Elba CM-104, Emblem Model M-18, Fen-Tone Model 500C, Fen-Tone Model FM-18, Herald Model M-102, Imperial Model DM-17, Lafayette Model 99-4511, Midland Model 22-104, Monarch Model MC-80, Olson Model M-102, Olson Model M-104, Philmore Model M-18, Realistic Model 33-929, Rystl Model CR-180, Rystl Model DY-38, Shield Model MC-80, Shield Model 102, Teisco Model CM-40, Teisco Model DM-302, Veritas Model V-110 and the Zephyr Model 40RC. As you can see, there were plenty of them made!
All this leads us to an interesting phenomenon that you'll see over and over, which you should always try to detect whenever you can. Many items that have become icons in their respective industries are so popular that not only are they collectibles, but even their vintage copycats have become collectibles! And that's precisely the case with this little Calrad microphone. Note that the side of the box tells it like it is - it's a just a cheaper condenser microphone that looks a lot like the RCA-77, that's all!
Another interesting thing here is that nearly all the RCA 77's copycats will be substantially smaller than the 77, which is really big. Unlike other microphone types, ribbon microphones actually generate such a miniscule electrical signal that they require a step-up transformer to step the current up so that the signal can actually be used by the equipment it's intended to be wired into. The RCA 77's size is partially due to the fact that it has one of these transformers built right into it.
Now, does this microphone work? Well, I never found out because I listed it as-is and untested. Keep in mind that the buyers of these microphones probably aren’t going to actually use them, so they probably wouldn’t be too concerned whether it worked or not. And in the case it did need repair, it’s relatively inexpensive circuitry (as opposed to the really expensive stuff inside a model 77 microphone) would make the repair a cheap one.
This vintage Calrad C-500 pill microphone sold on eBay for $64