no side tone on K2

[MARY HAYS CARNEY]

Don:
After much backing and resoldering, I finally got my K2 on the air. (The problems were popped then mismatched finals.)  Unfortunately, the side tone has stopped working, either in setting the tone or level from the menu, transmitting or in the test mode.  I can get power out on key down, just no tone.

With key down, there is no ac voltage out of pin 4 of the DAC(U8) on the control board or at the drain of Q5.  There is 5 V dc on pin 1 of U8.  I assume that U8 is bad, but before I attack this chip, is there anywhere else to look?

joe
KB3FBR
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[Don Wilhelm-4]

Joe,

The most likely thing is that the sidetone source has been accidently
toggled to U6 - 25.
Enter the menu for ST-L and edit the parameter (press EDIT) - then tap
DISPLAY to toggle between the two sources.  Stop when you hear sidetone.

73,
Don W3FPR

MARY HAYS CARNEY wrote:
> Don:
> After much backing and resoldering, I finally got my K2 on the air. (The problems were popped then mismatched finals.)  Unfortunately, the side tone has stopped working, either in setting the tone or level from the menu, transmitting or in the test mode.  I can get power out on key down, just no tone.
>
> With key down, there is no ac voltage out of pin 4 of the DAC(U8) on the control board or at the drain of Q5.  There is 5 V dc on pin 1 of U8.  I assume that U8 is bad, but before I attack this chip, is there anywhere else to look?
>
>  
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[OE5CSP-Chris]

<quote author="MARY HAYS CARNEY">
Don:
After much backing and resoldering, I finally got my K2 on the air. (The problems were popped then mismatched finals.)  Unfortunately, the side tone has stopped working, either in setting the tone or level from the menu, transmitting or in the test mode.  I can get power out on key down, just no tone.

With key down, there is no ac voltage out of pin 4 of the DAC(U8) on the control board or at the drain of Q5.  There is 5 V dc on pin 1 of U8.  I assume that U8 is bad, but before I attack this chip, is there anywhere else to look?

 Joe,

When I built the Kat 100 I also needed a firmware upgrade(U8). I got a faulty one-no sidetone any more- Elecraft sent me a new one and everything was fine again.

vy73, Chris-OE5CSP