[Elecraft] KSB2-Filter Measurements

[VR2BrettGraham]

G3RXQ shared with us some measurements he made & commented:

>This performance was very much better than I expected. The passband has, 
>however
>about a 2dB ripple in it.

I think it is this ripple that makes using my K2 on SSB seem tiring
to listen to as compared to other rigs.  Reducing the bandwidth on
the K2 makes it even more tiring as compared to other radios that
derive variable bandwidth filtering with two filters & the usual IF
gymnastics.

G3RXQ's comment that the KSB's filter working about as well as it is
probably spot on.  The same could probably be said for the CW filter.
The ripple - along with ultimate rejection (either due to filter or layout) -
could be much better & become obvious when using the K2 in more
demanding situations.  After a weekend of contesting, I get a
headache listening to a TS-950S - but I just can't pull some things
through on the K2 that I can with the 950 fitted with decent after-market
filters.  Even with the nasty high-frequency crud that comes from its
SCAF CW audio filter, I find I gravitate towards the 950 more than the
K2 as my running rig.  Whilst there are number of things about the 950
that stick out as being inferior to the K2 (like phase noise), IMHO
the filters make a big difference - making me wonder what a K2
would be like if we could INRAD it like other rigs.

Again, maybe not an issue for some, depending on one's operating
interests.  I agree with W3ICT - such "criticisms come only because
the K2 is a history making radio in most other respects".

73, VR2BrettGraham