[Elecraft] Dave Clark Microphone

[Ron D'Eau Claire]

Of course the K2 includes a microphone input level attenuator selected via
the MENU. I believe it's 10 dB as supplied. The resistor values can be
changed for a higher value, if needed. 

Ron AC7AC

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Ken Rice
Sent: Sunday, February 25, 2007 10:05 AM
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] Dave Clark Microphone


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.
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