[Elecraft] K3 Passband/DSP Filter Display Question ?

[Sam Morgan]

yes FC means Frequency Center
the astric * before the number indicates the APF shift is in the center
the .68 sez your center (your cw pitch) set to 680hz

so if you saw .670 or .690
there would be no * and your APF center
would now be 10 hz up .690 or down .670

some have found the ringing they experienced with APF
was fixed by shifting the APF center off by maybe 10-20hz
and using the RIT moved their receive the same amount

On 1/31/2014 12:48 PM, Phil Hystad wrote:
> I have had my K3 for four years but rarely make use of the passband
> tuning features.  Today though I was experimenting with APF and the
> passband controls and learned that I really do not know what I am
> doing.
>
> In particular, the VFO B display is a mystery to me during passband
> tuning and APF SHIFT tuning.  For example, in passband tuning (APF
> not enabled), the VFO B display says FC and then a number like 0.70
> or whatever.  What does "FC" mean (I can guess, but that would not be
> useful) and what is this number.  I scanned all the documents I have
> and have not found descriptions of the content of the VFO B readout
> during passband tuning.  I know it has something to do with shifting
> the frequency of center (I think) so maybe FC means Frequency Center.
> Also, there is an asterisk in the field, like:  FC  *0.68.  Maybe
> someone can interpret the meaning of that.
>
> If I knew the definition for passband tuning for the VFO B field
> content I could probably guess at the meaning of the APF enabled
> display which is similar such as:  APF  *0.68.
>
> I have found lots of description of passband tuning and that part of
> the display showing the passband width and position but nothing
> describing the VFO B contents (not covered in documentation on
> alternate VFO B displays either).
>
> 73, phil, K7PEH


-- 
GB & 73
K5OAI
Sam Morgan