[Elecraft] Anew k3 owner de ai5os.

[David Woolley]

On 03/05/2024 23:25, Justin Mann wrote:
> I notice that the rig has the original 2.8K filter installed, so I’m
> thinking that I should add a few more filter to optimize performance

You should first determine whether you are suffering a problem that will 
benefit from this.  XTAL filters will help if you are suffering from 
strong adjacent channel interference, but will degrade the pass band 
flatness, and, probably, the group delay characteristics (pulses will be 
more smeared out).  (I don't know if all the K3 filters are FIR, which 
is needed for ideal group delay behaviour.)

> with some different modes.  Were I to add a 250 HZ CW filter would that
> also work at 500 HZ?

An ideal 250Hz filter would limit the maximum bandwidth to 250 Hz.  It 
will be even less ideal than the DSP but will dominate the overall 
frequency response outside the 250 Hz (and even near the edges, within 
it).  I'd expect the response to be 10s of dB down before 500 Hz, maybe 
over 60.

-- 
David Woolley