[Elecraft] Elecraft] K3 PB Ctrl Shift .01/.05

[Richard Ferch]

KG0KP wrote:

> The bandwidth appears to be limited when using 10 hz and it is painfully 
> slow when the bandwidth is fairly wide.
> 
...
> What would be really nice, if possible, is to auto change to 10 hz shift 
> when you adjust your width below (pick a  number) 200 or so and back when 
> you go above that width (optionally?).

1. It is not the bandwidth that is limited, it is the range of the SHIFT 
control. For example, in DATA A, the bandwidth can be adjusted all the 
way up to 4 kHz, no differently from PB CTRL = 50 Hz. What is different 
is that the range of adjustment of the SHIFT control is limited to the 
range 1280 - 1720 Hz. As you noted, if the range were wider it would be 
painfully slow to adjust it more broadly anyway.

The best solution to this is what some software calls an ALIGN or OPT 
function. This works as follows: with a wide filter, find the signal you 
want by clicking on it in the waterfall; click on the ALIGN or OPT 
button which retunes your radio so that the signal you have selected is 
now on the optimal frequency (FC = 1500 Hz is the obvious choice in DATA 
A); and now adjust the filter bandwidth as narrow as you like. I do not 
know whether DM780 has such a function, but if it does, that would be 
much easier than using the SHIFT knob to chase stations up and down the 
waterfall.

2. If an automatic switch between 10 Hz and 50 Hz shift resolution with 
filter bandwidth is ever implemented, I would suggest that it kick in 
somewhere around 400-500 Hz, certainly not as narrow as 200 Hz. In RTTY, 
the widths where the 10 Hz shift resolution is most useful are those 
where the skirts of the filter and the skirts of the RTTY signal 
overlap. At a shift resolution of 50 Hz and with some choices of PITCH, 
this overlap could happen at filter bandwidths up to 350-400 Hz.

73,
Rich VE3KI