[Elecraft] K3 Rev C DSP with Low Freq Enhancement

[Mike Scott]

I have installed the beta version of the Low Pass filter board. It turned my
K3 into a whole different radio. I had been experiencing audio fatigue to
the point I just stopped using the K3 for CW. I know Paul says the audio is
one of the best designed audio circuits for a communications receiver. I say
it is now but not before. I may have had a singular issue with my K3 or I
have a singular set of ears.

Mike Scott - AE6WA
Tarzana, CA (DM04 / near LA)
NAQCC 3535
K3-100 #508 / KX1  #1311

> Unfortunately, the issue with the 12 kHz leakage (DAC clock?) and beat
> notes (+/- CW sidetone around 12 kHz) make for some awful audio in CW.
> I guess most folks don't hear it, but given previous reports from
> others, it is an issue.  I can't comfortably use the K3 for CW unless
> using outboard low-pass audio filters to knock the high end garbage  
> down
> to an in-audible level.
>
> 73
> Eric NO3M