[Elecraft] KPA1500 and FT8

David Woolley forums at david-woolley.me.uk
Mon Mar 5 05:03:00 EST 2018


I believe at least some of the DSP filters in the K3 are FIR (Finite 
Impulse Response) ones, which should be phase linear.  The roofing 
filters will not be phase linear, so I would think you could get away 
with using a narrow DSP filter, as long as you used a relatively wide 
roofing filter.

This will still leave the ADC, and the analogue circuitry between the 
roofing filter and it, open to overloads, but will protect the sound card.

On 04/03/18 21:15, Jim Brown wrote:
> There is a VERY good reason why WSJT developer, K1JT, advises users to 
> use wide IF bandwidth, and it's NOT the panoramic display. The reason is 
> that filters introduce phase shift in the passband, and phase shift is 
> the enemy of good decoding. The same physics, by



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