[Elecraft] APF in 4.16/2.63 works well!

[Joe Subich, W4TV]

 > I would like to be able to ***VARY THE Q*** with the width control and
 > LEAVE IT ON with a mild Q, and sharpen it as required.

The design goal was to duplicate the FT-1000D APF.  The FT-1000D has
no variable Q function.  What you are proposing is completely different
than the design parameters ... you want an Autek QF1 not the FT-1000D APF.

>> When APF is in there is no moderate setting, it takes over the
>> passband and makes copy of a signal up band difficult.

That's the goal of the FT-1000D APF ... single signal reception in
noise and QRM.  If you want a context filter, the original Dual PB
filter with it's variable with and shift fill that role.

>> ONLY when APF is on could we have the WIDTH tap toggle between APF
>> Q displaying APF Q=3 in lower display and between Roofing/DSP
>> bandwidth displaying BW 0.40??? You could do the same thing with
>> SHIFT to go back and forth between adjusting Roofing/DSP SHIFT
>> displaying FC *0.45 and APF *0.45.

Width/shift taps are already "taken" if the user has not chosen PB
Shift=.01.  There is no current requirement to select PB Shift=.01
in order to use APF and I hope that *someday* Wayne will give us the
ability to use LO-CUT-HI with PB Shift=.01.

73,

    ... Joe, W4TV

On 10/29/2010 12:58 PM, Guy Olinger K2AV wrote:
> APF has a very significant improvement on weak signals in the noise.
> I completely agree with prior posters.   HOWEVER...
>
> I would like to be able to ***VARY THE Q*** with the width control and
> LEAVE IT ON with a mild Q, and sharpen it as required.  If I can back
> it out to 2 dB with a width function I would probably leave that on
> all the time and grind in as needed.  I already do that with Width in
> weak cases that are on frequency.  ONLY when APF is on could we have
> the WIDTH tap toggle between APF Q displaying APF Q=3 in lower display
> and between Roofing/DSP bandwidth displaying BW  0.40???  You could do
> the same thing with SHIFT to go back and forth between adjusting
> Roofing/DSP SHIFT displaying FC *0.45 and APF *0.45.    Using WIDTH to
> control Q is intuitive.
>
> When APF is in there is no moderate setting, it takes over the
> passband and makes copy of a signal up band difficult.  It will
> require repeated use of DUAL PB to go in and out for weak signals and
> back out for normal use.  Use of a HOLD function as a frequent change
> is a problem.  In trying to get used to the HOLD on DUAL PB to go in
> and out of APF to hear in the rest of the channel,  I repeatedly hit
> NTCH instead.  HOLD's are only good for settings that persist for a
> while during operation.
>
> E.g. I don't need APF ONLY as a better substitute for 50 Hz.  I need
> it to work ALSO as a milder center emphasis inside the 400 Hz roofer,
> and be able to twist a knob somewhere to move between mild and sharp.
> Even with what appears to be only a 2 dB peaking around 450, the MP
> was improved inside its excellent dual INRAD 400 selectivity.
>
> If this is not done, it will be very difficult to use it well in a
> contest.  No easy-to-use variable Q is a deal-breaker for me.  In the
> end for contests it will cost Q's and will have to tell people to
> leave it off, just like NR. Only turn it on for a really weak one if
> you can remember how, and then turn it right back off.  Then when I
> get home chasing weak DX I'll turn it all back on again, and work some
> stuff I couldn't hear before.
>
> 73, Guy.
>
> On Fri, Oct 29, 2010 at 11:01 AM, drewko<drewko1 at verizon.net>  wrote:
>> Yes, I realize that. I would like to compare what is heard using the
>> APF filter to what is displayed by BeaconSee with its sub-noise signal
>> recovery algorithms.
>>
>> 73,
>> Drew
>> AF2Z
>>
>>
>> On Fri, 29 Oct 2010 10:55:38 -0400, you wrote:
>>
>>>
>>> I think you may be confused about what APF is.  It is NOT a waterfall or any
>>> kind of visual indicator.  It IS an Audio Peaking Filter (APF) meant to
>>> enhance weak signal audio using the processor between your ears.  It will
>>> not automatically show you where weak signals are in a spectrum, but if you
>>> know approximately where to look (either from a Packet spot or waterfall
>>> trace) it can help your ear/brain decode the CW audio buried in noise.
>>>
>>> 73,  Bill
>>
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