In article , Dave - wrote:
I recently acquired a nice Shure 55sw microphone (The "Elvis" Style)
and was wondering if I could adapt it to use on a modern rig
(Specifically a Yaesu FT-990 or an Icom 706 MKIIg.

The Shure has swtchable impedances as follows:

L = 25-50 Ohms (38 nominal)
M = 150-250 Ohms (150 nominal)
H = 35,000 Ohms (40,000 nominal)

According to my manuals the Yaesu mikes are 2000 ohms and the Icoms
are 600 ohms.

Try the M setting with the Icom and the H input with the Yaesu.

I have heard that the Shure was a popular studio mike and can produce
a nice high fidelity sound but can the impedance match a modern rig?

Actually, it's a pretty godawful mike, and it was by the standards of
the day as well. Mostly because of the grille design, which makes for
a very peaky upper midrange in comparison with the EV mikes, and which
also makes for very bad pattern control. With a communications mike, the
pattern control isn't quite as big a deal as for PA stuff, though. Try
it and see if you like it... it'll take ten minutes to make up a cable
so you can decide.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."