[Elecraft] K3 - DSP IF Width Increment

[Ian White GM3SEK]

Brett wrote:
>>
>>I agree that the 50Hz jumps do feel like much bigger schwacks in the
>>lower bandwidths but I don't feel them un-reasonably so...  How narrow
>>do you wish things to get?  25Hz?  10Hz? 1Hz?  Personally I don't know
>>what the right value is but I do think that 1Hz increments would be too
>>"smooth".  To the point of SLOW.

Since 1Hz increments were your own idea, you just answered yourself - 
and of course you're absolutely right  :-)

The problem is that the SHIFT/LO and WIDTH/HI encoders are 36 steps 
(40?) with a soft detent that gives very little tactile feedback. With 
50Hz shift increments and a 100Hz bandwidth, SHIFT covers the whole 
bandwidth in two small steps of the control. With a 50Hz bandwidth, one 
step takes you clear outside of the passband, so the SHIFT shift 
function doesn't work at all.


Gary wrote:
>On CW, I find the 50hz increments to work well for varying the bandwidth
>but prefer a smaller (I am used to 10hz) increment for Shift.  Tweaking the
>shift or PBT function often enhances readability for me, even with the
>narrow filters the K3 provides.
>
>73, Gary W7TEA

On reflection, I'd agree with Gary that  50Hz increments in width are 
OK, and the main improvement is needed in the shift.  10Hz increments 
are the smallest that can be displayed, and would certainly be a big 
improvement at very narrow bandwidths.

However, at wider bandwidths a 10Hz shift increment would take too many 
turns of the control to cover the range. As a very simple compromise, 
10Hz might be switched in automatically for bandwidths of 500Hz and 
below.

Alternatively, this scheme would  give smoother transitions:

10Hz increments (the smallest displayable) for all bandwidths <250Hz

20Hz increments (the next available step) for 250-1000Hz

Keep 50Hz increments for bandwidths >1000Hz.




-- 

73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek