[Elecraft] K3 - Filter suggestions for new builder

[Al Lorona]

Right, Don!

I still believe that many K3 users are under the erroneous impression that the 
roofing filter determines the receiver bandwidth. It does not. The HI and LO 
knobs do. 

The only thing the roofing filter does is determine the MAXIMUM possible 
bandwidth of the receiver.

In 99% of cases, an SSB roofing filter is good enough. (That statement is going 
to draw some fire.)

It's a little bit like this: the roofing filter is like the credit limit on your 
Visa card. You can't go any higher than that. But in any typical month, you 
spend far less than that... and on the K3 the amount you *actually* spend is set 
by the HI and LO cut controls.

This is why I advised the original poster: you wanna know what 1.8 kHz sounds 
like? Set your HI LO controls to a bandwidth of 1.8 kHz. Then decide whether it 
1/ is tolerable; and 2/ increases intelligibility enough to make the investment 
worth it. I happen to think that 1.8 kHz is too narrow. But that's just me.

________________________________

I say that because in all cases with the K3, it is the DSP that 
determines the filter width rather than the roofing filter.  What I am 
saying is that even if you put in a 1.8k filter, SSB at a 1.8k width 
will sound the same as it does right now using only the DSP.


73,
Don W3FPR