[Elecraft] Dave Clark Microphone

[RBrigham1 at cs.com]

In a message dated 2/25/2007 10:05:17 AM Pacific Standard Time, 
radiok3vv at gmail.com writes: 
> As others have mentioned,  the M-7A electret's output will be too high
> for good performance on the K2 (400mV RMS ±6dB into 150 ohm load @
> 1kHz for 114dB SPL input), so you'll need to pad it down.  And you'll
> need a series 1uF capacitor (again, as others have mentioned).
> 
> Jim, W6JVE, uses an aviation headset on the K2 with the Radio Shack
> 1000:8 ohm transformer:
> 
>      
> http://www.ac6rm.net/mailarchive/html/elecraft-list/2003-02/msg00306.html
> 
> If you don't care about keeping the Clark headset in stock form, you
> can replace the M-7A element with the three-dollar Radio Shack
> electret element that will work with the DC voltage and expected mic
> output level at the K2's mic jack.
> 
>      
> http://www.ac6rm.net/mailarchive/html/elecraft-list/2004-01/msg00197.html
> 
> Please let us know how it works out.
This is good info. I already have an adapter box that I use to drop the 
headphone impedence from 150 ohms to about 8 ohms, so I was planning to add a few 
more parts to it to handle the mic. Thanks for interest and info and I will 
definitely let the group know how it turns out. 

But first, I have to finish my K2. I have completed the Stage 1 checks 
successfully and am in the middle of populating the RF board. Stay tuned...

Rob
KC6ROC  K2 #5924