[Elecraft] Icom IC-SM20 Mike wiring

[Bill Coleman]

On 1/16/03 11:14 AM, kr7x@attbi.com at kr7x@attbi.com wrote:

>Has anyone wired up the mike header for an Icom IC-SM20 mike? I am doing 
>this 
>for a friend for his K2. He told me that it needs 8v. I see that the K2 pins 
>only offer 5v. Any problems with this, should I just use the Icom wiring 
>in the 
>ksb2 manual with a 10k resistor? Any help would be appreciated.

I have a similar situation.

For my Kenwood TS-430S, about 2 years ago I wired up a K1KP-style voice 
keyer. This is a design that used a cheap Radio Shack analog recording 
chip, which isn't available any more.

The voice keyer needs +8 volts, because it has its own +5 regulator. I 
didnt' want to modify it, since I still need to interchange it with the 
Kenwood.

Here's what I did.

1) I used a two-terminal jumper block as a connector. I soldered one end 
of a #30 teflon-coated wire-wrap wire to it. 

2) The other end is soldered to the RF board, at a point that supplies +8 
volts from the control board.

3) Plug the jumper block onto ONE TERMINAL on the microphone side of the 
microphone jumper pins. (I used pin 5 to match the Kenwood)

Since the RF board and the front panel normally stay connected together 
after initial assembly, there's little danger of plugging the jumper 
block onto the wrong pin. If you are worried about it, take a spare 
jumper block and put it over the other pin on the K2 side.

This makes a nice, easily reversible mod.

Oh, and the K2 works pretty well with the Voice Keyer....


Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr@arrl.net
Quote: "Not within a thousand years will man ever fly!"
            -- Wilbur Wright, 1901