[Elecraft] RE: Wide SSB Caps or not

[Dave White]

I operate exclusively SSB with the K2, and I've used all bandwidths; the 
original "2.2", the optional "2.4", and "2.6".  All function well.  If you 
are interested in DX or contesting, the narrow bandwidths are preferred on 
crowded bands, from both a TX and RX perspective, but limit flexibility.

For casual operating and rag chewing, I prefer the 2.6Khz bandwidth; the 
vocal tone quality on TX and RX is more natural and pleasant to listen to. I 
set the FL2 and FL3 XFIL settings to alternately shift the passband about 
400Hz higher and lower than the SSB FL1 passband.  This allows you to 
minimize some interference from a close-in signal.  I set FL4 to use the 
standard "CW" filter at 1.9Khz. bandwidth; it helps on very crowded band 
conditions.

Another factor is whether you have the KDSP2 audio DSP unit. If so, setting 
the DSP skirts allows even more flexibility as you cycle through 4 
user-defined bandwidths using AFIL.  I now find the 2.6Khz. SSB filter 
bandwidth and the DSP to be the best combination for my operating style. 
Setting the "standard" (SF 1) DSP filter to 2.7Khz does a nice job in 
cleaning up the filter skirts left over from the SSB crystal filter; its 
passband is not symmetrical. One option I wish the K2 firmware had was the 
ability to slave the AFIL selection to the XFIL setting; this would allow 
the IF -AF filtering and passband to be applied in paired combinations. 
Perhaps after the new amplifiers are released, we'll be treated to a K2 
firmware upgrade (Wayne: hint, hint ...)

Regardless, using Spectrogram (or some other audio "bandscope") is essential 
for setting the filter widths and passbands correctly. Remember to 
"calibrate" your computer-based audio bandscope against a known tone (ie: 
WWV 500 or 600Hz. modulated signal) as not all sound cards are accurate.

Regards

Dave White
ve6drw at rac.ca