[Elecraft] D104 mic

[Tom W8JI]

It will sound great if you add a J310 or similar JFET source follower. Very 
flat clean response.

A source follower is very simple.  Use a low voltage .01 uF or .05 uF disc 
cap to the gate. Use a 100k to 1 meg ohm resistor from gate to ground. Put a 
560 ohm source resistor to ground, and couple the source to the K3 through a 
.47 uF cap. The drain is bypassed and decoupled to a 9 volt battery or clean 
12 volt supply. If you have a lot of RF you might need to decouple the audio 
output line.

The size of the gate resistor will control loading on the D104 and the 
frequency response. The higher the resistance the more the low frequency 
response.

Until I started using a Sennheiser computer headset I used a D104 head on 
all my rigs.

73 Tom





----- Original Message ----- 
From: "Chris Hembree" <w7cth at yahoo.com>
To: <elecraft at mailman.qth.net>
Sent: Friday, July 09, 2010 7:11 PM
Subject: [Elecraft] D104 mic


> Anyone ever use a D-104 (non amp) on a K3. How does it sound?
> Chris W7CTH
>
>
>
>
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