[Elecraft] K3 APF Adjustable Q

[Joe Subich, W4TV]

>> however the fixed Q has a bit of ring and at times I would like to
 >> back it off (widen) it just a tad.

This is the same mistake Yaesu made in the FT-1000D; de-Qing the
original APF made it useless in later radios.  This is the very
reason not to add adjustable Q or reduce the Q of the APF currently
in field test.  If you want a less aggressive filter that is centered
on the sidetone, use Dual PB ... that's exactly what it is designed
to do (and it does a very good job when used as designed).

Adjustable center frequency is very important ... particularly when
PB CTRL is set for Shift=.05 (to allow LO-CUT-HI to function) as
the 50 Hz increments too course to tune APF using the VFO.  The user
also needs the ability to adjust the peak independently in order to
peak up an off frequency caller and not "chase them up the band."

73,

    ... Joe, W4TV


On 10/31/2010 8:58 AM, Steve Ellington wrote:
> If I had a choice between variable center frequency and adjustable Q, I
> would choose adjustable Q.
>
> My logic is: The center frequency automatically follows the sidetone
> frequency so I have no need to adjust it however the fixed Q has a bit of
> ring and at times I would like to back it off (widen) it just a tad.
>
> Otherwise it's a HUGE improvement, sounds great and I wish to thank those
> who made it possible.
>
> 73
> N4LQ
> Steve
>
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