[Elecraft] K3 Filter Advice

[Bill Tippett]

WU7R:
  >I didn't order any filters not knowing which ones to order.

         Since Elecraft has now posted the data I needed, here's what 
I'm probably going with:

Main RX:  2.7k stock, 1.8k 8-pole, 500 Hz 5-pole
Sub RX:  2.7k stock, 500 Hz 5-pole

         My reasoning is that the 1.8 will be useful both for 
contesting SSB and also S&P CW.  I like the 500 over the 400 because 
it is 130 Hz wider and the IMD performance is nearly identical.  I 
might later decide to try a 1.0 if the 1.8 is not sufficient, but my 
guess is it will be OK.  In Orion I used a 600 Hz 4-pole most of the 
time and then an 8-pole 1.8 kHz for contesting SSB and CW S&P.  The 
way these DSP rigs work, the effective bandwidth of a 1800 Hz filter 
on CW is actually more like 900 + the CW Pitch you select...so if you 
like a 400 Hz Pitch, the effective BW of an 1800 is actually more 
like 1300Hz (due to the fact that the DSP truncates the filter 
response below 0 Hz).

         Eventually I may order another K3 for SO2R with Main RX only 
and the same set of Main filters above.  The reason I don't need the 
1.8k for the Sub above is that I mainly plan use use it for diversity 
RX on CW (on 160 meters).

                                 73,  Bill  W4ZV

P.S. For most folks (non-contesters or low band DXers), the stock 
2.7k filters are probably all you need.  Remember that these filters 
are *only* for IMD/BDR issues with signals above about S9+30.  Your 
final selectivity is still determined by the DSP filters with 
selectable BWs every 50 Hz.