[Elecraft] K2 Microphone Substitutions

[Jim Brown]

On Sat, 30 Aug 2008 16:37:26 -0400, Robert Freedman wrote:

>I have been 'gifted' with a Shure model 444 magnetic microphone to use 
>with my K2. It (the microphone) is thirty years old, and was reported to 
>be in excellent condition.  Does anyone use this model, and what pin 
>connections do you use?  Or should I just forget it.  It was designed to 
>have a response curve tailored for amateur SSB use.

The Shure 444 is an excellent ham mic, and should work well with your K2. 
I'm looking at a 1963 data sheet for it right now (which you can probably 
find on the Shure website). Black is the hot side of the mic, shield is the 
return of the mic. 

The PTT switch does two things. When it's UP (not pushed), it shorts out 
the mic capsule. When you push it, it un-shorts the capsule and connects 
White to the Shield.  There is also a switch inside the mic base that 
enables or disables PTT to the White wire. "Normal" is enabled (that is, 
PTT works). 

The original 444 is a high Z mic. Later versions (444D) is switchable highZ 
- low Z. The switch is in the base, I think. 

73,

Jim K9YC