[Elecraft] K3 high pitched tone and noise when keying the mic

[Fred Jensen]

12.8 is pretty low.  I run my Yaesu FP-1030A linear supply at 14.7 V for 
K3 and K2.  By the time the DC gets to the inside of the K3, it's about 
14.5 and higher voltages reduce TX IMD some, not that the K3 isn't 
really low IMD to begin with.

Not all power supplies are created equal ... in a host of ways ... but a 
really solid one can make a big difference in a number of ways.  The 
FP-1030A is linear, heavy, and the voltmeter does not move at 100W CW 
keying.

I'd turn yours up a bit.  14.0 might be a good point.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the Cal QSO Party 1-2 Oct 2016
- www.cqp.org

On 11/15/2015 4:54 PM, Paul Taenzer wrote:
> The 'low battery' issue was the problem.
>
> I tweaked the power supply voltage up to 12.8 or so and no more
> noise!

> de Paul VA3LX