[Elecraft] KRX3 Filter

[Ed Muns]

> >> Does a 2.7Khz filter come as a standard filter with the KRX3 
> >> receiver?
> >
> > Yes.  See the K3 order web page.
> 
> My understanding is that with that filter and the DSP, if one 
> is not heavily into contests and isn't in an area with 30 + 
> over 9 sigs, the other filters may not be a requirement, even 
> though a nicety.
> 
> I'd love some feedback form any of the beta testers who may 
> have operated with the minimal kind of filtering.

My advice is "yes", the 2.7 kHz roofing filter is all anyone needs.  The
narrower roofing filters add nothing the vast majority of time.  Only in
extreme situations where very strong adjacent signals are present, outside
the passband but inside the wider roofing filter, will a narrower roofer
help the DSP do its final filtering job.  I keep reminding people that other
radios, e.g., the Icom 756 Pro series, have a 15 kHz roofing filter and rely
on DSP for the final IF filtering, as does the K3.  Only a very few, more
expensive, radios (Orion, Orion II, Icom 7800, etc.) offer switchable,
narrower roofers.  And, very few operating situations require the narrower
filters.

Moreover, adding filters to the K3 in the future is trivial.  They simply
plug in and a screw is inserted for comprehensive grounding.  Get some
experience with the radio in your operation scenarios before committing to
additional filters.

73,
Ed - W0YK