Re: [Elecraft] K3 APF Adjustable Q

[juergen]

Hi Morris

The IC7600 has some kind of Q adjustment in its APF feature. The Icom IC7600 
has "SOFT" and "SHARP"settings for the APF. This is also combined with the 
WIDE, MID  and narrow settings for the APF. This would be similar in operation 
to having a dedicated Q control. In all honesty the APF as implemented in the 
FT1000D works better than that in the IC7600. On any setting of the IC7600's 
APF control it is not worth  engaging most of the time.

APF has to be an instantaneous control that does not require a multiplicity  of 
settings. The one in the FT1000D is a  dream on the low bands. 

Out of curiosity what radio has a APF filter with a Q control? 

I have a old Mizuho AP-1D Audio Processor/peak filter. This APF filter has a 
fixed bandwidth of 900hz and its variable from 500 to 1000hz. It does not have 
a Q control however it works better than the one in the Icom 7600.


73
John



--- On Fri, 10/29/10, Roy Morris  wrote:

> From: Roy Morris 
> Subject: [Elecraft] K3 APF Adjustable Q
> To: elecraft@mailman.qth.net
> Date: Friday, October 29, 2010, 8:08 PM
> An adjustable Q would be a desirable
> APF feature.  Also the SHIFT control needs to be more
> responsive.  It sometimes doesn't keep up with changes
> while sweeping the peak frequency.  I hope these tweeks
> can be added in future firmware.  Thanks,  Roy
> Morris  W4WFB
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Re: [Elecraft] K3 APF Adjustable Q

[Al Lorona]

This was exactly my point the other day. The simpler it is, the more useful it 
will be in a variety of circumstances. The more tweaking it requires, the less 
useful it will be in a pressure situation.

Al  W6LX




> Juergen said:
> APF has to be an instantaneous control that does not require a multiplicity  
> of 
>settings.
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Re: [Elecraft] K3 APF Adjustable Q

[Robert Harmon]

I have a different opinion my ham friends.
I don't mind at all an extra knob turning / button pushing to utilize APF.
You don't need the APF functionality all the time.
It is a tool to be used in the real tough cases where the signal is right down 
in the noise and you need that extra help to pull him out.
I'm afraid any dumbing down of the circuit to make it more automated and 
eliminate an extra button push, etc would also reduce its effectiveness.
If we think about what the circuit is trying to accomplish it needs to be as 
effective as it can be !  That tiny bit of improvement in signal to noise 
ratio it provides is critical, lets focus on optimizing it !   Like I said you 
don't need it all the time but I sure want it in my tool box when needed.
I am excited about the prospect of having it integrated into the K3.  There 
just isn't any better CW radio in my opinion.  For me its like having your
cake and eat it to with APF added.  I wanted to voice my fear of reducing its 
effectiveness, thats all.  

73,
Bob
K6UJ





On Oct 30, 2010, at 4:30 PM, Al Lorona wrote:

> This was exactly my point the other day. The simpler it is, the more useful 
> it 
> will be in a variety of circumstances. The more tweaking it requires, the 
> less 
> useful it will be in a pressure situation.
> 
> Al  W6LX
> 
> 
> 
> 
>> Juergen said:
>> APF has to be an instantaneous control that does not require a multiplicity  
>> of 
>> settings.
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Re: [Elecraft] K3 APF Adjustable Q

[Steve Ellington]

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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Re: [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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Re: [Elecraft] K3 APF Adjustable Q

[Steve Ellington]

If the caller is off frequency I would just use RIT to center him in my 
passband as usual and let APF do it's thing.
Having used outboard APFs for years, the ability to adjust it's selectivity 
is very important. If the band is quiet and the signal is very weak, I would 
adjust the APF nearly to the point of oscillation then back it off a tad. If 
the signal is weak but there is a lot of QRN, I would back off the 
selectivity a bit further but still take advantage of some extra peaking 
capability.

N4LQ
Steve

- Original Message - 
From: "Joe Subich, W4TV" 
To: 
Sent: Sunday, October 31, 2010 10:27 AM
Subject: Re: [Elecraft] K3 APF Adjustable Q


>
>>> 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
>>
>> __
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
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>>
>> This list hosted by: http://www.qsl.net
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>>
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Re: [Elecraft] K3 APF Adjustable Q

[Roy Morris]

We already have the peak sweep with the SHIFT control.  It would be great to 
have variable Q with the WIDTH control.   Varying the amount of Q is desirable 
so the peak can be adjusted to reduce any ringing that might be present.  Roy 
Morris  W4WFB
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Re: [Elecraft] K3 APF Adjustable Q

[Guy Olinger K2AV]

I'd say for variable Q, the tightest setting should be just what is
there now.  So no one is losing anything.

What I have been trying to point out is that there is a general
benefit for a milder shape, that one MAY leave on all the time, and
tweak to tight as needed.  MP's EDSP, 450 Hz sidetone, NR=D, Contour=
11 oclock as an example of a mild contour that is really helpful.

Being able to tune the APF tight setting around allows me to match the
"tone" of the almost ring to the remembered tone of the weak station
and have it come up when I hit it.

If the choice is sharp or no APF and no APF tune, I have to RIT the
station to sidetone.  This has a couple of disadvantages.

First, if running in a contest, and there are very loud stations up
and down (aren't there always?), RIT up and down is going to let the
co-channel guys in under the roofing filter and into pre-APF digital
space. That can't be useful.  Second, continuing to tune the station
in becomes hard if the station stops or fades out because there is
nothing to "calibrate" the completion of RIT twiddle other than
hearing the tone from the station move to sidetone, and now it's
stopped or faded.

The presence of APF tune, or variable Q does not disadvantage anyone
who doesn't need them, the same way all the really neat digital stuff
does not disadvantage the straight CW operators.  The current setting
and shape of APF is definitely the right max Q setting, and does very
well for me.

I just want a mild Q setting to imitate the shape I had with the MP
all those years.  Those who hear it will get it, just like those that
hear the sharp APF for the first time and try it, get it.  I think a
lot of people will leave a mild Q on ALL THE TIME for general
operating.  It lowers the level of the stuff up and down a little
without any ringing, but still allows one to hear up and down for off
frequency callers.  For me it's an EASIER listen for hours on end.

73, Guy.

On Sun, Oct 31, 2010 at 10:47 AM, Steve Ellington  wrote:
> If the caller is off frequency I would just use RIT to center him in my
> passband as usual and let APF do it's thing.
> Having used outboard APFs for years, the ability to adjust it's selectivity
> is very important. If the band is quiet and the signal is very weak, I would
> adjust the APF nearly to the point of oscillation then back it off a tad. If
> the signal is weak but there is a lot of QRN, I would back off the
> selectivity a bit further but still take advantage of some extra peaking
> capability.
>
> N4LQ
> Steve
>
> - Original Message -----
> From: "Joe Subich, W4TV" 
> To: 
> Sent: Sunday, October 31, 2010 10:27 AM
> Subject: Re: [Elecraft] K3 APF Adjustable Q
>
>
>>
>>>> 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
>>>
>>> __
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Elecraft@mailman.qth.net
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/don

Re: [Elecraft] K3 APF Adjustable Q

[Matt Zilmer]

There are also other considerations.  In QRQ mode, RIT is N/A.  So
other than tuning VFO A to follow the peak, use SHIFT to do it.  Also,
SHIFT uses a 10 Hz resolution independent from the VFO tuning rate.
This doesn't leave many of the overloaded controls on the UI for a
PEAK control.

Having a changeable Q would be nice too, but as peaky as it is, it's
probably about optimal.  Lyle does good work, and probably agonized
for some time about how high and tight to make it.  Really, there's no
control for the Q since WIDTH is left for normal use.  Unless one is
"found".

BUT - who knows what the final outcome will be.  Elecraft can be full
of surprises.

73,
matt W6NIA


On Sun, 31 Oct 2010 08:58:57 -0400, you 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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Re: [Elecraft] K3 APF Adjustable Q

[Vic K2VCO]

I agree that we should not give up the tunable APF. For one thing, RIT is not 
available if 
QRQ CW is on. I like the option to set the DSP bandwidth to say, 1 kHz, and 
then use the 
APF tune to pick out the guy I want to copy. This might be useful when running 
in a 
contest: set the DSP to kill the loud guys on either side of you and then use 
the APF to 
peak your caller.

Variable Q might be desirable in some circumstances, but I wouldn't want to 
give up either 
the APF tuning or the DSP width adjustment to make it possible.

Somebody mentioned being able to adjust the Q 'just below the point of 
oscillation'. While 
I like the nostalgic reference to the Heath Q Multiplier and the National 
Select-o-ject, I 
suspect that Lyle is quaking in his boots about the possibility of allowing the 
DSP to 
oscillate!

On 10/31/2010 9:03 AM, Guy Olinger K2AV wrote:
> I'd say for variable Q, the tightest setting should be just what is
> there now.  So no one is losing anything.
>
> What I have been trying to point out is that there is a general
> benefit for a milder shape, that one MAY leave on all the time, and
> tweak to tight as needed.  MP's EDSP, 450 Hz sidetone, NR=D, Contour=
> 11 oclock as an example of a mild contour that is really helpful.
>
> Being able to tune the APF tight setting around allows me to match the
> "tone" of the almost ring to the remembered tone of the weak station
> and have it come up when I hit it.
>
> If the choice is sharp or no APF and no APF tune, I have to RIT the
> station to sidetone.  This has a couple of disadvantages.
>
> First, if running in a contest, and there are very loud stations up
> and down (aren't there always?), RIT up and down is going to let the
> co-channel guys in under the roofing filter and into pre-APF digital
> space. That can't be useful.  Second, continuing to tune the station
> in becomes hard if the station stops or fades out because there is
> nothing to "calibrate" the completion of RIT twiddle other than
> hearing the tone from the station move to sidetone, and now it's
> stopped or faded.
>
> The presence of APF tune, or variable Q does not disadvantage anyone
> who doesn't need them, the same way all the really neat digital stuff
> does not disadvantage the straight CW operators.  The current setting
> and shape of APF is definitely the right max Q setting, and does very
> well for me.
>
> I just want a mild Q setting to imitate the shape I had with the MP
> all those years.  Those who hear it will get it, just like those that
> hear the sharp APF for the first time and try it, get it.  I think a
> lot of people will leave a mild Q on ALL THE TIME for general
> operating.  It lowers the level of the stuff up and down a little
> without any ringing, but still allows one to hear up and down for off
> frequency callers.  For me it's an EASIER listen for hours on end.
>
> 73, Guy.
>
> On Sun, Oct 31, 2010 at 10:47 AM, Steve Ellington  
> wrote:
>> If the caller is off frequency I would just use RIT to center him in my
>> passband as usual and let APF do it's thing.
>> Having used outboard APFs for years, the ability to adjust it's selectivity
>> is very important. If the band is quiet and the signal is very weak, I would
>> adjust the APF nearly to the point of oscillation then back it off a tad. If
>> the signal is weak but there is a lot of QRN, I would back off the
>> selectivity a bit further but still take advantage of some extra peaking
>> capability.
>>
>> N4LQ
>> Steve
>>
>> - Original Message -
>> From: "Joe Subich, W4TV"
>> To:
>> Sent: Sunday, October 31, 2010 10:27 AM
>> Subject: Re: [Elecraft] K3 APF Adjustable Q
>>
>>
>>>
>>>>> 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 u

Re: [Elecraft] K3 APF Adjustable Q

[Steve Ellington]

By "oscillate" I was thinking of my HQ-150's Q multiplier. It does remind me 
of APF but of course is a totally different thing.
As APF now exist in the K3, I choose to use it only when necessary. If it 
had variable Q, it would be on constantly and I would adjust Q as needed.
One advantage to an external APF box is how the sidetone is filtered and 
ends up sound so sweet. Normally sidetones sound a bit dull but APF can 
brighten them up and make them sound so pure and clean.
Steve

- Original Message - 
From: "Vic K2VCO" 
To: 
Sent: Sunday, October 31, 2010 12:25 PM
Subject: Re: [Elecraft] K3 APF Adjustable Q


>I agree that we should not give up the tunable APF. For one thing, RIT is 
>not available if
> QRQ CW is on. I like the option to set the DSP bandwidth to say, 1 kHz, 
> and then use the
> APF tune to pick out the guy I want to copy. This might be useful when 
> running in a
> contest: set the DSP to kill the loud guys on either side of you and then 
> use the APF to
> peak your caller.
>
> Variable Q might be desirable in some circumstances, but I wouldn't want 
> to give up either
> the APF tuning or the DSP width adjustment to make it possible.
>
> Somebody mentioned being able to adjust the Q 'just below the point of 
> oscillation'. While
> I like the nostalgic reference to the Heath Q Multiplier and the National 
> Select-o-ject, I
> suspect that Lyle is quaking in his boots about the possibility of 
> allowing the DSP to
> oscillate!
>
> On 10/31/2010 9:03 AM, Guy Olinger K2AV wrote:
>> I'd say for variable Q, the tightest setting should be just what is
>> there now.  So no one is losing anything.
>>
>> What I have been trying to point out is that there is a general
>> benefit for a milder shape, that one MAY leave on all the time, and
>> tweak to tight as needed.  MP's EDSP, 450 Hz sidetone, NR=D, Contour=
>> 11 oclock as an example of a mild contour that is really helpful.
>>
>> Being able to tune the APF tight setting around allows me to match the
>> "tone" of the almost ring to the remembered tone of the weak station
>> and have it come up when I hit it.
>>
>> If the choice is sharp or no APF and no APF tune, I have to RIT the
>> station to sidetone.  This has a couple of disadvantages.
>>
>> First, if running in a contest, and there are very loud stations up
>> and down (aren't there always?), RIT up and down is going to let the
>> co-channel guys in under the roofing filter and into pre-APF digital
>> space. That can't be useful.  Second, continuing to tune the station
>> in becomes hard if the station stops or fades out because there is
>> nothing to "calibrate" the completion of RIT twiddle other than
>> hearing the tone from the station move to sidetone, and now it's
>> stopped or faded.
>>
>> The presence of APF tune, or variable Q does not disadvantage anyone
>> who doesn't need them, the same way all the really neat digital stuff
>> does not disadvantage the straight CW operators.  The current setting
>> and shape of APF is definitely the right max Q setting, and does very
>> well for me.
>>
>> I just want a mild Q setting to imitate the shape I had with the MP
>> all those years.  Those who hear it will get it, just like those that
>> hear the sharp APF for the first time and try it, get it.  I think a
>> lot of people will leave a mild Q on ALL THE TIME for general
>> operating.  It lowers the level of the stuff up and down a little
>> without any ringing, but still allows one to hear up and down for off
>> frequency callers.  For me it's an EASIER listen for hours on end.
>>
>> 73, Guy.
>>
>> On Sun, Oct 31, 2010 at 10:47 AM, Steve Ellington 
>> wrote:
>>> If the caller is off frequency I would just use RIT to center him in my
>>> passband as usual and let APF do it's thing.
>>> Having used outboard APFs for years, the ability to adjust it's 
>>> selectivity
>>> is very important. If the band is quiet and the signal is very weak, I 
>>> would
>>> adjust the APF nearly to the point of oscillation then back it off a 
>>> tad. If
>>> the signal is weak but there is a lot of QRN, I would back off the
>>> selectivity a bit further but still take advantage of some extra peaking
>>> capability.
>>>
>>> N4LQ
>>> Steve
>>>
>>> - Original Message -
>>> From: "Joe Subich, W4TV"
>>> To:
>>> Sent: Sunday, October 31, 2010 10:27 AM
>>> Subject: Re: [Elecraft] K3 APF 

Re: [Elecraft] K3 APF Adjustable Q

[Byron Servies]

On Saturday, October 30, 2010, Robert Harmon  wrote:

> It is a tool to be used in the real tough cases where the signal is right 
> down in the noise and you need that extra help to pull him out.

Naieve newbie question, because im missing something here: if the
signal you want is that hard to receive, what are the chances the
other station will be able to hear your reply?

Byron KI6NUL


-- 
- Northern California Contest Club
- CU in the 2011 Cal QSO Party 1-2 Oct 2011
- www.cqp.org
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Re: [Elecraft] K3 APF Adjustable Q

[Vic K2VCO]

Pretty good, if the other station is QRP and you are not, if the other station 
is DX and 
you are a high-power DXer, or if the other station has a K3 too!

On 10/31/2010 10:05 AM, Byron Servies wrote:
> On Saturday, October 30, 2010, Robert Harmon  wrote:
>
>> It is a tool to be used in the real tough cases where the signal is right 
>> down in the
>> noise and you need that extra help to pull him out.
>
> Naieve newbie question, because im missing something here: if the signal you 
> want is
> that hard to receive, what are the chances the other station will be able to 
> hear your
> reply?
>
> Byron KI6NUL
>
>

-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/
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Re: [Elecraft] K3 APF Adjustable Q

[W2RU - Bud Hippisley]

If he's running 5 watts to a coat hanger antenna on a remote island, and you're 
using a 1500-watt amplifier and 3-element beam to go with your beautiful K3, 
the chances are quite good:-)

Besides...the APF feature will help us all be able to copy the "/QRP" at the 
end of his call.

Bud, W2RU

On Oct 31, 2010, at 1:05 PM, Byron Servies wrote:

> Naive newbie question, because im missing something here: if the
> signal you want is that hard to receive, what are the chances the
> other station will be able to hear your reply?

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Re: [Elecraft] K3 APF Adjustable Q

[Ron D'Eau Claire]

Even domestic run-of-the mill contacts with people using a limited antenna
such as a short whip sitting on the patio or a random wire in the attic in
an antenna-restricted neighborhood often produce a much weaker than expected
signal. 

Personally, I try to work the weakest signals I can read well. Find much
more interesting rag-chews that way, e.g. homebrewers trying something
haywired on the bench, QRPers and portable stations in a camp site somewhere
or perhaps bicycle or pedestrian mobile. One night I worked a guy on Mt.
Hood snugged up in a snow cave running 1 watt on 40 meters to a hunk of wire
lying on the snow outside. 

Ron AC7AC

-Original Message-

Pretty good, if the other station is QRP and you are not, if the other
station is DX and 
you are a high-power DXer, or if the other station has a K3 too!

On 10/31/2010 10:05 AM, Byron Servies wrote:
> On Saturday, October 30, 2010, Robert Harmon  wrote:
>
>> It is a tool to be used in the real tough cases where the signal is right
down in the
>> noise and you need that extra help to pull him out.
>
> Naieve newbie question, because im missing something here: if the signal
you want is
> that hard to receive, what are the chances the other station will be able
to hear your
> reply?
>
> Byron KI6NUL
>
>

-- 

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Re: [Elecraft] K3 APF Adjustable Q

[Kok Chen]

On Oct 31, 2010, at 10/3110:05 AM, Byron Servies wrote:

> Naieve newbie question, because im missing something here: if the  
> signal you want is that hard to receive, what are the chances the  
> other station will be able to hear your reply?

Since I use simple antennas, and even though I always run barefooted,  
I *always* assume a DXpedition to an isolated island can copy me when  
I can barely copy them above the noise.

Although Reciprocity Theory states that if both of you use the same  
power, the received power at the two antenna terminals will be the  
same independent of what antennas are at each end, other things  
determine if he can copy you better than you can copy him.

The obvious factor that influence whether he can copy you is therefore  
obviously the amount of power that you use compared to the amount of  
power that he uses.

However, another factor, arguably more important, is the antennas'  
directivity and where the directivity are aimed at.  If his antenna is  
more directive than yours by 3 dB, all else being equal, he has a 3 dB  
of SNR advantage.  If the arrival angle of his signal at your antenna  
is 10 dB below where your antenna actually peaks, while your signal  
arrives at his antenna where the response of his antenna peaks, you  
have yet another 10 dB disadvantage, etc.

The same SNR argument applies to how noisy his local RF environment is  
compared to your environment.

And of course, how optimal and easy to use the filtering at his end is  
to pull your signal out of the noise, which is what the APF is all  
about for CW (and correspondingly, the use of matched filters for  
digital modes).

73
Chen, W7AY

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Re: [Elecraft] K3 APF Adjustable Q

[Bill VanAlstyne W5WVO]

So yes, there are a BUNCH of variables that determine whether the DX station 
is going to hear your signal.

My approach -- though this has been confined to 6 meters up until recently, 
when I got back on HF CW and digital modes with a VERY small footprint --  
has always been to do whatever I can to make sure the other guy CAN hear me. 
That means the best antennas and the most power I can put together, in 
combination of course with the smartest operating practices I can learn and 
master. The QRO part of that, well, that's just me. A lot of guys love the 
thrill of beating their heads against a brick wall -- sorry, I mean, the 
thrill of working DX with QRP and small antennas. :-)

Notwithstanding big differences in things like power and antennas, however, 
I think the two principle reasons for assuming the DX station will 
eventually be able to copy you are:

(1) Their locations are probably quieter than yours -- sometimes (as in an 
island DXpedition location) a LOT quieter, maybe as much as 10 dB or more 
quieter.

(2) Guys who run DXpeditions or who run their home stations from rare 
entities are usually very, very good operators -- probably better than you 
are, for sure better than I am.

Since I've been back on HF CW chasing DX with my puny little sloper and 100 
watts, I've seen many, many DX stations go to extreme efforts to pull 
through a complete QSO with a weak W/K station (like me) that they 
absolutely do NOT need to work for any pragmatic reason, other than personal 
pride in operating skills. And some of these guys' skills are just amazing.

Bill W5WVO



-Original Message- 
From: Kok Chen
Sent: Sunday, October 31, 2010 18:44
To: Elecraft Reflector
Subject: Re: [Elecraft] K3 APF Adjustable Q

On Oct 31, 2010, at 10/3110:05 AM, Byron Servies wrote:

> Naieve newbie question, because im missing something here: if the
> signal you want is that hard to receive, what are the chances the
> other station will be able to hear your reply?

Since I use simple antennas, and even though I always run barefooted,
I *always* assume a DXpedition to an isolated island can copy me when
I can barely copy them above the noise.

Although Reciprocity Theory states that if both of you use the same
power, the received power at the two antenna terminals will be the
same independent of what antennas are at each end, other things
determine if he can copy you better than you can copy him.

The obvious factor that influence whether he can copy you is therefore
obviously the amount of power that you use compared to the amount of
power that he uses.

However, another factor, arguably more important, is the antennas'
directivity and where the directivity are aimed at.  If his antenna is
more directive than yours by 3 dB, all else being equal, he has a 3 dB
of SNR advantage.  If the arrival angle of his signal at your antenna
is 10 dB below where your antenna actually peaks, while your signal
arrives at his antenna where the response of his antenna peaks, you
have yet another 10 dB disadvantage, etc.

The same SNR argument applies to how noisy his local RF environment is
compared to your environment.

And of course, how optimal and easy to use the filtering at his end is
to pull your signal out of the noise, which is what the APF is all
about for CW (and correspondingly, the use of matched filters for
digital modes).

73
Chen, W7AY

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Re: [Elecraft] K3 APF Adjustable Q

[Joe Subich, W4TV]

>> What I have been trying to point out is that there is a general
>> benefit for a milder shape, that one MAY leave on all the time,
>> and tweak to tight as needed.

If you want a "milder" shape, use Dual PB filter with a 400 - 500 Hz
background and 100 Hz foreground.  That can certainly be left on
all the time and the APF switched on when needed ... at least once
all of the controls have been programmed.

73,

... Joe, W4TV


On 10/31/2010 12:03 PM, Guy Olinger K2AV wrote:
> I'd say for variable Q, the tightest setting should be just what is
> there now.  So no one is losing anything.
>
> What I have been trying to point out is that there is a general
> benefit for a milder shape, that one MAY leave on all the time, and
> tweak to tight as needed.  MP's EDSP, 450 Hz sidetone, NR=D, Contour=
> 11 oclock as an example of a mild contour that is really helpful.
>
> Being able to tune the APF tight setting around allows me to match the
> "tone" of the almost ring to the remembered tone of the weak station
> and have it come up when I hit it.
>
> If the choice is sharp or no APF and no APF tune, I have to RIT the
> station to sidetone.  This has a couple of disadvantages.
>
> First, if running in a contest, and there are very loud stations up
> and down (aren't there always?), RIT up and down is going to let the
> co-channel guys in under the roofing filter and into pre-APF digital
> space. That can't be useful.  Second, continuing to tune the station
> in becomes hard if the station stops or fades out because there is
> nothing to "calibrate" the completion of RIT twiddle other than
> hearing the tone from the station move to sidetone, and now it's
> stopped or faded.
>
> The presence of APF tune, or variable Q does not disadvantage anyone
> who doesn't need them, the same way all the really neat digital stuff
> does not disadvantage the straight CW operators.  The current setting
> and shape of APF is definitely the right max Q setting, and does very
> well for me.
>
> I just want a mild Q setting to imitate the shape I had with the MP
> all those years.  Those who hear it will get it, just like those that
> hear the sharp APF for the first time and try it, get it.  I think a
> lot of people will leave a mild Q on ALL THE TIME for general
> operating.  It lowers the level of the stuff up and down a little
> without any ringing, but still allows one to hear up and down for off
> frequency callers.  For me it's an EASIER listen for hours on end.
>
> 73, Guy.
>
> On Sun, Oct 31, 2010 at 10:47 AM, Steve Ellington  
> wrote:
>> If the caller is off frequency I would just use RIT to center him in my
>> passband as usual and let APF do it's thing.
>> Having used outboard APFs for years, the ability to adjust it's selectivity
>> is very important. If the band is quiet and the signal is very weak, I would
>> adjust the APF nearly to the point of oscillation then back it off a tad. If
>> the signal is weak but there is a lot of QRN, I would back off the
>> selectivity a bit further but still take advantage of some extra peaking
>> capability.
>>
>> N4LQ
>> Steve
>>
>> - Original Message -
>> From: "Joe Subich, W4TV"
>> To:
>> Sent: Sunday, October 31, 2010 10:27 AM
>> Subject: Re: [Elecraft] K3 APF Adjustable Q
>>
>>
>>>
>>>>> 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.
>&g

Re: [Elecraft] K3 APF Adjustable Q

[Steve Ellington]

Joe
What you describe is not 'variable'.
N4LQ
Steve

- Original Message - 
From: "Joe Subich, W4TV" 
To: "Guy Olinger K2AV" 
Cc: 
Sent: Sunday, October 31, 2010 4:47 PM
Subject: Re: [Elecraft] K3 APF Adjustable Q


>
>>> What I have been trying to point out is that there is a general
>>> benefit for a milder shape, that one MAY leave on all the time,
>>> and tweak to tight as needed.
>
> If you want a "milder" shape, use Dual PB filter with a 400 - 500 Hz
> background and 100 Hz foreground.  That can certainly be left on
> all the time and the APF switched on when needed ... at least once
> all of the controls have been programmed.
>
> 73,
>
>... Joe, W4TV
>
>
> On 10/31/2010 12:03 PM, Guy Olinger K2AV wrote:
>> I'd say for variable Q, the tightest setting should be just what is
>> there now.  So no one is losing anything.
>>
>> What I have been trying to point out is that there is a general
>> benefit for a milder shape, that one MAY leave on all the time, and
>> tweak to tight as needed.  MP's EDSP, 450 Hz sidetone, NR=D, Contour=
>> 11 oclock as an example of a mild contour that is really helpful.
>>
>> Being able to tune the APF tight setting around allows me to match the
>> "tone" of the almost ring to the remembered tone of the weak station
>> and have it come up when I hit it.
>>
>> If the choice is sharp or no APF and no APF tune, I have to RIT the
>> station to sidetone.  This has a couple of disadvantages.
>>
>> First, if running in a contest, and there are very loud stations up
>> and down (aren't there always?), RIT up and down is going to let the
>> co-channel guys in under the roofing filter and into pre-APF digital
>> space. That can't be useful.  Second, continuing to tune the station
>> in becomes hard if the station stops or fades out because there is
>> nothing to "calibrate" the completion of RIT twiddle other than
>> hearing the tone from the station move to sidetone, and now it's
>> stopped or faded.
>>
>> The presence of APF tune, or variable Q does not disadvantage anyone
>> who doesn't need them, the same way all the really neat digital stuff
>> does not disadvantage the straight CW operators.  The current setting
>> and shape of APF is definitely the right max Q setting, and does very
>> well for me.
>>
>> I just want a mild Q setting to imitate the shape I had with the MP
>> all those years.  Those who hear it will get it, just like those that
>> hear the sharp APF for the first time and try it, get it.  I think a
>> lot of people will leave a mild Q on ALL THE TIME for general
>> operating.  It lowers the level of the stuff up and down a little
>> without any ringing, but still allows one to hear up and down for off
>> frequency callers.  For me it's an EASIER listen for hours on end.
>>
>> 73, Guy.
>>
>> On Sun, Oct 31, 2010 at 10:47 AM, Steve Ellington 
>> wrote:
>>> If the caller is off frequency I would just use RIT to center him in my
>>> passband as usual and let APF do it's thing.
>>> Having used outboard APFs for years, the ability to adjust it's 
>>> selectivity
>>> is very important. If the band is quiet and the signal is very weak, I 
>>> would
>>> adjust the APF nearly to the point of oscillation then back it off a 
>>> tad. If
>>> the signal is weak but there is a lot of QRN, I would back off the
>>> selectivity a bit further but still take advantage of some extra peaking
>>> capability.
>>>
>>> N4LQ
>>> Steve
>>>
>>> - Original Message -
>>> From: "Joe Subich, W4TV"
>>> To:
>>> Sent: Sunday, October 31, 2010 10:27 AM
>>> Subject: Re: [Elecraft] K3 APF Adjustable Q
>>>
>>>
>>>>
>>>>>> 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 frequenc

Re: [Elecraft] K3 APF Adjustable Q

[Guy Olinger K2AV]

You've brought that up several times, Joe, but that is not the sound,
and how do you use it in CW with Shift increment at .01, particularly
with DUAL PB turning APF on and off?  73, Guy.

On Sun, Oct 31, 2010 at 4:47 PM, Joe Subich, W4TV  wrote:
>
>>> What I have been trying to point out is that there is a general
>>> benefit for a milder shape, that one MAY leave on all the time,
>>> and tweak to tight as needed.
>
> If you want a "milder" shape, use Dual PB filter with a 400 - 500 Hz
> background and 100 Hz foreground.  That can certainly be left on
> all the time and the APF switched on when needed ... at least once
> all of the controls have been programmed.
>
> 73,
>
>   ... Joe, W4TV
>
>
> On 10/31/2010 12:03 PM, Guy Olinger K2AV wrote:
>>
>> I'd say for variable Q, the tightest setting should be just what is
>> there now.  So no one is losing anything.
>>
>> What I have been trying to point out is that there is a general
>> benefit for a milder shape, that one MAY leave on all the time, and
>> tweak to tight as needed.  MP's EDSP, 450 Hz sidetone, NR=D, Contour=
>> 11 oclock as an example of a mild contour that is really helpful.
>>
>> Being able to tune the APF tight setting around allows me to match the
>> "tone" of the almost ring to the remembered tone of the weak station
>> and have it come up when I hit it.
>>
>> If the choice is sharp or no APF and no APF tune, I have to RIT the
>> station to sidetone.  This has a couple of disadvantages.
>>
>> First, if running in a contest, and there are very loud stations up
>> and down (aren't there always?), RIT up and down is going to let the
>> co-channel guys in under the roofing filter and into pre-APF digital
>> space. That can't be useful.  Second, continuing to tune the station
>> in becomes hard if the station stops or fades out because there is
>> nothing to "calibrate" the completion of RIT twiddle other than
>> hearing the tone from the station move to sidetone, and now it's
>> stopped or faded.
>>
>> The presence of APF tune, or variable Q does not disadvantage anyone
>> who doesn't need them, the same way all the really neat digital stuff
>> does not disadvantage the straight CW operators.  The current setting
>> and shape of APF is definitely the right max Q setting, and does very
>> well for me.
>>
>> I just want a mild Q setting to imitate the shape I had with the MP
>> all those years.  Those who hear it will get it, just like those that
>> hear the sharp APF for the first time and try it, get it.  I think a
>> lot of people will leave a mild Q on ALL THE TIME for general
>> operating.  It lowers the level of the stuff up and down a little
>> without any ringing, but still allows one to hear up and down for off
>> frequency callers.  For me it's an EASIER listen for hours on end.
>>
>> 73, Guy.
>>
>> On Sun, Oct 31, 2010 at 10:47 AM, Steve Ellington
>>  wrote:
>>>
>>> If the caller is off frequency I would just use RIT to center him in my
>>> passband as usual and let APF do it's thing.
>>> Having used outboard APFs for years, the ability to adjust it's
>>> selectivity
>>> is very important. If the band is quiet and the signal is very weak, I
>>> would
>>> adjust the APF nearly to the point of oscillation then back it off a tad.
>>> If
>>> the signal is weak but there is a lot of QRN, I would back off the
>>> selectivity a bit further but still take advantage of some extra peaking
>>> capability.
>>>
>>> N4LQ
>>> Steve
>>>
>>> - Original Message -
>>> From: "Joe Subich, W4TV"
>>> To:
>>> Sent: Sunday, October 31, 2010 10:27 AM
>>> Subject: Re: [Elecraft] K3 APF Adjustable Q
>>>
>>>
>>>>
>>>>>> 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 i

Re: [Elecraft] K3 APF Adjustable Q

[Paul Christensen]

I suspect the moment variable Q were to become available, soon thereafter, 
the next request would be for variable peaking amplitude. At some point, 
Elecraft must decide what they want from APF -- is it an emulation of a 
filter used in a transceiver from twenty years ago?  Or, is it something 
more?  If it's more, then it may as well be a full-blown parametric EQ 
channel with variable amplitude, variable frequency, and variable Q.

I tend to agree with Al's comment where he noted that sometimes the most 
effective controls are the one's that are easily accessible to the op 
without the need for added manipulation.

Paul, W9AC

- Original Message - 
From: "Guy Olinger K2AV" 
To: "Joe Subich, W4TV" 
Cc: 
Sent: Sunday, October 31, 2010 7:33 PM
Subject: Re: [Elecraft] K3 APF Adjustable Q


You've brought that up several times, Joe, but that is not the sound,
and how do you use it in CW with Shift increment at .01, particularly
with DUAL PB turning APF on and off?  73, Guy.

On Sun, Oct 31, 2010 at 4:47 PM, Joe Subich, W4TV  wrote:
>
>>> What I have been trying to point out is that there is a general
>>> benefit for a milder shape, that one MAY leave on all the time,
>>> and tweak to tight as needed.
>
> If you want a "milder" shape, use Dual PB filter with a 400 - 500 Hz
> background and 100 Hz foreground. That can certainly be left on
> all the time and the APF switched on when needed ... at least once
> all of the controls have been programmed.
>
> 73,
>
> ... Joe, W4TV
>
>
> On 10/31/2010 12:03 PM, Guy Olinger K2AV wrote:
>>
>> I'd say for variable Q, the tightest setting should be just what is
>> there now. So no one is losing anything.
>>
>> What I have been trying to point out is that there is a general
>> benefit for a milder shape, that one MAY leave on all the time, and
>> tweak to tight as needed. MP's EDSP, 450 Hz sidetone, NR=D, Contour=
>> 11 oclock as an example of a mild contour that is really helpful.
>>
>> Being able to tune the APF tight setting around allows me to match the
>> "tone" of the almost ring to the remembered tone of the weak station
>> and have it come up when I hit it.
>>
>> If the choice is sharp or no APF and no APF tune, I have to RIT the
>> station to sidetone. This has a couple of disadvantages.
>>
>> First, if running in a contest, and there are very loud stations up
>> and down (aren't there always?), RIT up and down is going to let the
>> co-channel guys in under the roofing filter and into pre-APF digital
>> space. That can't be useful. Second, continuing to tune the station
>> in becomes hard if the station stops or fades out because there is
>> nothing to "calibrate" the completion of RIT twiddle other than
>> hearing the tone from the station move to sidetone, and now it's
>> stopped or faded.
>>
>> The presence of APF tune, or variable Q does not disadvantage anyone
>> who doesn't need them, the same way all the really neat digital stuff
>> does not disadvantage the straight CW operators. The current setting
>> and shape of APF is definitely the right max Q setting, and does very
>> well for me.
>>
>> I just want a mild Q setting to imitate the shape I had with the MP
>> all those years. Those who hear it will get it, just like those that
>> hear the sharp APF for the first time and try it, get it. I think a
>> lot of people will leave a mild Q on ALL THE TIME for general
>> operating. It lowers the level of the stuff up and down a little
>> without any ringing, but still allows one to hear up and down for off
>> frequency callers. For me it's an EASIER listen for hours on end.
>>
>> 73, Guy.
>>
>> On Sun, Oct 31, 2010 at 10:47 AM, Steve Ellington
>> wrote:
>>>
>>> If the caller is off frequency I would just use RIT to center him in my
>>> passband as usual and let APF do it's thing.
>>> Having used outboard APFs for years, the ability to adjust it's
>>> selectivity
>>> is very important. If the band is quiet and the signal is very weak, I
>>> would
>>> adjust the APF nearly to the point of oscillation then back it off a 
>>> tad.
>>> If
>>> the signal is weak but there is a lot of QRN, I would back off the
>>> selectivity a bit further but still take advantage of some extra peaking
>>> capability.
>>>
>>> N4LQ
>>> Steve
>>>
>>> - Original Message -
>>> From: "Joe Subich, W4TV"
>>> To:
>>> Sent: Sunday, October 31, 

Re: [Elecraft] K3 APF Adjustable Q

[Gary Ferdinand]

As one who has had his ears pounded for hundred (thousands?) of hours by DX
contest stations whilst trying to listen to a deep weak layer among the
cacophony of strong stations, I am very excited by what I'm hearing
regarding the field test of APF.  

While tinkering with the details, Elecraft, please think hard about what
both Paul and Guy had to say.  APF could be lots of things but it doesn't
have to be something with every degree of freedom variable.  Nor does one
have to emulate every sound of every audio DSP from rigs past.  

However, if APF can be implemented in such a way that the operator can
establish a *persistent* setting that-for him or her-reduces the fatigue of
concentrating on the CW "noise," such capability would improve the K3.
Having the exact setting as the MP that Guy references?  Not necessarily.
Having the same result?  It sure would be of value to my (aging) ears.  And
I would most likely use that persistent setting for all CW operation, casual
or competitive. 

Gary W2CS


> From W9AC:
> I suspect the moment variable Q were to become available, soon thereafter,
> the next request would be for variable peaking amplitude. At some point,
> Elecraft must decide what they want from APF -- is it an emulation of a
> filter used in a transceiver from twenty years ago?  Or, is it something
> more?  If it's more, then it may as well be a full-blown parametric EQ
> channel with variable amplitude, variable frequency, and variable Q.
> 
> >> From K2AV:
> >> I just want a mild Q setting to imitate the shape I had with the MP
> >> all those years. Those who hear it will get it, just like those that
> >> hear the sharp APF for the first time and try it, get it. I think a
> >> lot of people will leave a mild Q on ALL THE TIME for general
> >> operating. It lowers the level of the stuff up and down a little
> >> without any ringing, but still allows one to hear up and down for off
> >> frequency callers. For me it's an EASIER listen for hours on end.
> >>

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Re: [Elecraft] K3 APF Adjustable Q

[Ron D'Eau Claire]

Good point, Paul, but my experience with this sort of filter says that
variable Q also affects the peaking amplitude. 

That is, the higher Q is obtained with more feedback which results in more
gain.

Ron AC7AC


-Original Message-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Paul Christensen
Sent: Sunday, October 31, 2010 4:50 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] K3 APF Adjustable Q

I suspect the moment variable Q were to become available, soon thereafter, 
the next request would be for variable peaking amplitude. At some point, 
Elecraft must decide what they want from APF -- is it an emulation of a 
filter used in a transceiver from twenty years ago?  Or, is it something 
more?  If it's more, then it may as well be a full-blown parametric EQ 
channel with variable amplitude, variable frequency, and variable Q.

I tend to agree with Al's comment where he noted that sometimes the most 
effective controls are the one's that are easily accessible to the op 
without the need for added manipulation.

Paul, W9AC

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Re: [Elecraft] K3 APF Adjustable Q

[Robert Harmon]

It makes sense to me Joe, (sorry Guy)  

If you want a "milder shape" you don't really need APF.
Milder shape is the opposite of "peaking"

Bob
K6UJ



On Oct 31, 2010, at 4:33 PM, Guy Olinger K2AV wrote:

> You've brought that up several times, Joe, but that is not the sound,
> and how do you use it in CW with Shift increment at .01, particularly
> with DUAL PB turning APF on and off?  73, Guy.
> 
> On Sun, Oct 31, 2010 at 4:47 PM, Joe Subich, W4TV  wrote:
>> 
>>>> What I have been trying to point out is that there is a general
>>>> benefit for a milder shape, that one MAY leave on all the time,
>>>> and tweak to tight as needed.
>> 
>> If you want a "milder" shape, use Dual PB filter with a 400 - 500 Hz
>> background and 100 Hz foreground.  That can certainly be left on
>> all the time and the APF switched on when needed ... at least once
>> all of the controls have been programmed.
>> 
>> 73,
>> 
>>   ... Joe, W4TV
>> 
>> 
>> On 10/31/2010 12:03 PM, Guy Olinger K2AV wrote:
>>> 
>>> I'd say for variable Q, the tightest setting should be just what is
>>> there now.  So no one is losing anything.
>>> 
>>> What I have been trying to point out is that there is a general
>>> benefit for a milder shape, that one MAY leave on all the time, and
>>> tweak to tight as needed.  MP's EDSP, 450 Hz sidetone, NR=D, Contour=
>>> 11 oclock as an example of a mild contour that is really helpful.
>>> 
>>> Being able to tune the APF tight setting around allows me to match the
>>> "tone" of the almost ring to the remembered tone of the weak station
>>> and have it come up when I hit it.
>>> 
>>> If the choice is sharp or no APF and no APF tune, I have to RIT the
>>> station to sidetone.  This has a couple of disadvantages.
>>> 
>>> First, if running in a contest, and there are very loud stations up
>>> and down (aren't there always?), RIT up and down is going to let the
>>> co-channel guys in under the roofing filter and into pre-APF digital
>>> space. That can't be useful.  Second, continuing to tune the station
>>> in becomes hard if the station stops or fades out because there is
>>> nothing to "calibrate" the completion of RIT twiddle other than
>>> hearing the tone from the station move to sidetone, and now it's
>>> stopped or faded.
>>> 
>>> The presence of APF tune, or variable Q does not disadvantage anyone
>>> who doesn't need them, the same way all the really neat digital stuff
>>> does not disadvantage the straight CW operators.  The current setting
>>> and shape of APF is definitely the right max Q setting, and does very
>>> well for me.
>>> 
>>> I just want a mild Q setting to imitate the shape I had with the MP
>>> all those years.  Those who hear it will get it, just like those that
>>> hear the sharp APF for the first time and try it, get it.  I think a
>>> lot of people will leave a mild Q on ALL THE TIME for general
>>> operating.  It lowers the level of the stuff up and down a little
>>> without any ringing, but still allows one to hear up and down for off
>>> frequency callers.  For me it's an EASIER listen for hours on end.
>>> 
>>> 73, Guy.
>>> 
>>> On Sun, Oct 31, 2010 at 10:47 AM, Steve Ellington
>>>  wrote:
>>>> 
>>>> If the caller is off frequency I would just use RIT to center him in my
>>>> passband as usual and let APF do it's thing.
>>>> Having used outboard APFs for years, the ability to adjust it's
>>>> selectivity
>>>> is very important. If the band is quiet and the signal is very weak, I
>>>> would
>>>> adjust the APF nearly to the point of oscillation then back it off a tad.
>>>> If
>>>> the signal is weak but there is a lot of QRN, I would back off the
>>>> selectivity a bit further but still take advantage of some extra peaking
>>>> capability.
>>>> 
>>>> N4LQ
>>>> Steve
>>>> 
>>>> - Original Message -
>>>> From: "Joe Subich, W4TV"
>>>> To:
>>>> Sent: Sunday, October 31, 2010 10:27 AM
>>>> Subject: Re: [Elecraft] K3 APF Adjustable Q
>>>> 
>>>> 
>>>>> 
>>>>>>> however the fixed Q has a bit of ring and at times I would like to
>>>>>&

Re: [Elecraft] K3 APF Adjustable Q

[Jim Brown]

On 10/31/2010 11:44 AM, Kok Chen wrote:
> The same SNR argument applies to how noisy his local RF environment is
> compared to your environment

This is often the dominant factor.  When I lived in a Chicago 
residential neighborhood, my S-meter rarely got below S7 on band noise 
with narrow CW filters.  Here in the Santa Cruz Mountains, it's often 
more like S3.  If you assume 4 dB per S-unit (typical for most radios), 
that's 16 dB. That means if the other guy has that S7 noise level, I've 
got to run 1,000 watts to be heard as well as I would hear 25 watts from 
him.

73, Jim K9YC
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Re: [Elecraft] K3 APF Adjustable Q

[David Woolley (E.L)]

Quote para 2, both points:  Reciprocity still applies with respect to 
gain and off axis effects.  If the receive antenna is down by 3dB, it 
will be down by 3dB EIRP when transmitting; if down by 10dB, the EIRP 
will be down 10dB.

Quote para 3: Local noise does make a real difference and will 
compromise reciprocity.

Top quoted only by list policy.

Kok Chen wrote:
> Although Reciprocity Theory states that if both of you use the same 
> power, the received power at the two antenna terminals will be the same 
> independent of what antennas are at each end, other things determine if 
> he can copy you better than you can copy him.

> However, another factor, arguably more important, is the antennas' 
> directivity and where the directivity are aimed at.  If his antenna is 
> more directive than yours by 3 dB, all else being equal, he has a 3 dB 
> of SNR advantage.  If the arrival angle of his signal at your antenna is 
> 10 dB below where your antenna actually peaks, while your signal arrives 
> at his antenna where the response of his antenna peaks, you have yet 
> another 10 dB disadvantage, etc.

> The same SNR argument applies to how noisy his local RF environment is 
> compared to your environment.


-- 
David Woolley
"we do not overly restrict the subject matter on the list, and we
encourage postings on a wide range of amateur radio related topics"
List Guidelines 
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Re: [Elecraft] K3 APF Adjustable Q

[The Smiths]

Joe,
 
For some reason you keep thinking that Elecraft's APF is being designed and 
programmed by Yaesu engineers  Why is it that just because Yaesu made a 
mistake with their rig that it means Elecraft has to destroy THEIR APF just 
because they choose to add an adjustable Q control?  You have to have 
confidence that the APF can remain exactly the same as Lyle and the gang has 
written it while still adding the ability to open it up some?  Just because 
Yaesu programmers weren't talented enough not to destroy what they had built 
doesn't mean that Elecraft will make the same mistake.
Furthermore there are Alpha testers like myself that will make sure that once 
the variable Q has been put in that when set to the Minimum (narrowest) setting 
that it will still act and feel like it does now.  Of course you too could do 
the same as an Alfa software tester.  This isn't Yaesu where no one listens to 
the users once they choose to make a change or adjustment to the code... Your 
say WILL matter if things sound different once the feature has been improved 
for others.  I really don't think that you're giving Elecraft, it's 
programmers, or the Alpha testers such as myself enough credit.
 
I'm in favor of having a variable Q on this APF system.  It will help improve 
copy with a tight algorithm that Lyle has written for this one, while at the 
same time allowing me to open the Q so that I can copy not as weak signals with 
gain, and less ringing.  I believe that Lyle will not destroy his own code by 
adding a feature that Enhances the operation of what he's already created for 
us.  If he does, I will be the first to let him know so he can re-program it.  
The Dual pass band filter is nice, yes, but if you've used your DPB filter in 
the K3 you know as well as I do that it acts NOTHING like the APF with a wider 
Q in suppressing noise and improving gain as we're seeing on this current APF.  
Again, this is NOT a Yaesu rig... 
 

 
> Date: Sun, 31 Oct 2010 10:27:33 -0400
> From: li...@subich.com
> To: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] K3 APF Adjustable Q
> 
> 
> >> 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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> >
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Re: [Elecraft] K3 APF Adjustable Q

[The Smiths]

I vote to have both.  I find that moving the Fc off center from my IF helps 
reduce the ringing that I get. I think you should give that a try Steve.  Keep 
your IF center (SHIFT) then after you have used the CWT (or your ear) to tune 
someone in, drop their town down 20Hz, now activate the APF, then move the APF 
-20Hz, you'll not only peak their signal, but you'll also have reduced a lot of 
the ringing noise that you would normally get sitting in the center of the IF 
passband.  This is argument to KEEP the Fc knob.  Now, if you choose to keep 
your APF centered on the Pitch center (IF Center, passband center) than I 
believe that the variable Q would be very handy as well.  So looks like that's 
argument for BOTH.. Not one or the other.
 
> From: n...@carolina.rr.com
> To: k...@pacbell.net; alor...@sbcglobal.net
> Date: Sun, 31 Oct 2010 08:58:57 -0400
> CC: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] K3 APF Adjustable Q
> 
> 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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Re: [Elecraft] K3 APF Adjustable Q

[The Smiths]

100% agreed.  Where it is now is perfect for the narrowest position.. a little 
adjustment to open it up for different conditions is what the doctor ordered.  
No one suffers anything so long as they keep it where THEY feel fit to.
Maybe this is a mistake in understanding that some people are having.. No one 
is asking that the current Q setting be made wider when it becomes variable, 
we're asking that it stays the same, but has the ability to open up a little 
too... 
 
> Date: Sun, 31 Oct 2010 12:03:28 -0400
> From: olin...@bellsouth.net
> To: n...@carolina.rr.com
> CC: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] K3 APF Adjustable Q
> 
> I'd say for variable Q, the tightest setting should be just what is
> there now. So no one is losing anything.
> 
> What I have been trying to point out is that there is a general
> benefit for a milder shape, that one MAY leave on all the time, and
> tweak to tight as needed. MP's EDSP, 450 Hz sidetone, NR=D, Contour=
> 11 oclock as an example of a mild contour that is really helpful.
> 
> Being able to tune the APF tight setting around allows me to match the
> "tone" of the almost ring to the remembered tone of the weak station
> and have it come up when I hit it.
> 
> If the choice is sharp or no APF and no APF tune, I have to RIT the
> station to sidetone. This has a couple of disadvantages.
> 
> First, if running in a contest, and there are very loud stations up
> and down (aren't there always?), RIT up and down is going to let the
> co-channel guys in under the roofing filter and into pre-APF digital
> space. That can't be useful. Second, continuing to tune the station
> in becomes hard if the station stops or fades out because there is
> nothing to "calibrate" the completion of RIT twiddle other than
> hearing the tone from the station move to sidetone, and now it's
> stopped or faded.
> 
> The presence of APF tune, or variable Q does not disadvantage anyone
> who doesn't need them, the same way all the really neat digital stuff
> does not disadvantage the straight CW operators. The current setting
> and shape of APF is definitely the right max Q setting, and does very
> well for me.
> 
> I just want a mild Q setting to imitate the shape I had with the MP
> all those years. Those who hear it will get it, just like those that
> hear the sharp APF for the first time and try it, get it. I think a
> lot of people will leave a mild Q on ALL THE TIME for general
> operating. It lowers the level of the stuff up and down a little
> without any ringing, but still allows one to hear up and down for off
> frequency callers. For me it's an EASIER listen for hours on end.
> 
> 73, Guy.
> 
> On Sun, Oct 31, 2010 at 10:47 AM, Steve Ellington  
> wrote:
> > If the caller is off frequency I would just use RIT to center him in my
> > passband as usual and let APF do it's thing.
> > Having used outboard APFs for years, the ability to adjust it's selectivity
> > is very important. If the band is quiet and the signal is very weak, I would
> > adjust the APF nearly to the point of oscillation then back it off a tad. If
> > the signal is weak but there is a lot of QRN, I would back off the
> > selectivity a bit further but still take advantage of some extra peaking
> > capability.
> >
> > N4LQ
> > Steve
> >
> > - Original Message -
> > From: "Joe Subich, W4TV" 
> > To: 
> > Sent: Sunday, October 31, 2010 10:27 AM
> > Subject: Re: [Elecraft] K3 APF Adjustable Q
> >
> >
> >>
> >>>> 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
> >>

Re: [Elecraft] K3 APF Adjustable Q

[Philippe Trottet]

I agree with the comments  about the use of the DPB filter who act as a APF 
with wider Q.
May be the suggestion is to give more "flexibility" to the DBP filter in order 
to let the K3 user choosing what would be the best  in its own suppressing 
noise environment. 
73's
Philippe A65BI

>>> The Smiths  01-11-2010 12:24 >>>

Joe,

For some reason you keep thinking that Elecraft's APF is being designed and 
programmed by Yaesu engineers  Why is it that just because Yaesu made a 
mistake with their rig that it means Elecraft has to destroy THEIR APF just 
because they choose to add an adjustable Q control?  You have to have 
confidence that the APF can remain exactly the same as Lyle and the gang has 
written it while still adding the ability to open it up some?  Just because 
Yaesu programmers weren't talented enough not to destroy what they had built 
doesn't mean that Elecraft will make the same mistake.
Furthermore there are Alpha testers like myself that will make sure that once 
the variable Q has been put in that when set to the Minimum (narrowest) setting 
that it will still act and feel like it does now.  Of course you too could do 
the same as an Alfa software tester.  This isn't Yaesu where no one listens to 
the users once they choose to make a change or adjustment to the code... Your 
say WILL matter if things sound different once the feature has been improved 
for others.  I really don't think that you're giving Elecraft, it's 
programmers, or the Alpha testers such as myself enough credit.

I'm in favor of having a variable Q on this APF system.  It will help improve 
copy with a tight algorithm that Lyle has written for this one, while at the 
same time allowing me to open the Q so that I can copy not as weak signals with 
gain, and less ringing.  I believe that Lyle will not destroy his own code by 
adding a feature that Enhances the operation of what he's already created for 
us.  If he does, I will be the first to let him know so he can re-program it.  
The Dual pass band filter is nice, yes, but if you've used your DPB filter in 
the K3 you know as well as I do that it acts NOTHING like the APF with a wider 
Q in suppressing noise and improving gain as we're seeing on this current APF.  
Again, this is NOT a Yaesu rig... 



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Re: [Elecraft] K3 APF Adjustable Q

[Joe Subich, W4TV]

>> For some reason you keep thinking that Elecraft's APF is being
>> designed and programmed by Yaesu engineers

No, I'm saying that there are significant reasons *not* to do
variable Q:

1) there is no available control.  The "Width" control everyone
seems to want to use is already used in both the shift/width
and LO-CUT-HI modes.  I for one, don't want to give up the
use of the Width control when APF is active.

2) reducing the Q will make APF much less effective as shown by
history with the FT-1000D.  The later version of the FT-1000D
was ineffective compared to the original circuit in the 1000D
and FT-990.

3) The broader peaking (selectivity) of the MP/MK V contour circuit
so often cited as a prototype for "adjustable Q" is already
available using the existing Dual PB filter.

>> I'm in favor of having a variable Q on this APF system. It will
>> help improve copy with a tight algorithm that Lyle has written
 >> for this one, while at the same time allowing me to open the Q
 >> so that I can copy not as weak signals with gain, and less
 >> ringing.

Ringing is a result of the selectivity and the fact that the APF
is implemented as an Infinite Impulse Response (IIR) filter.  In
order to reduce the ringing you *MUST* reduce the selectivity and
that loss of selectivity will destroy the benefit of the APF.

There is very little difference in absolute selectivity between 30 Hz
in the alpha APF and the 50 Hz minimum selectivity in the standard
DSP filters.  Since even the 50 Hz DSP filter has a modest but 
detectable ring, adding the ability to "de-Q" the APF would provide
no benefit that can't already be achieved using either the 50 Hz
DSP or Dual PB filters.

>> I believe that Lyle will not destroy his own code by adding a
>> feature that Enhances the operation of what he's already created
 >> for us.

The whole point is that adding the ability to de-Q the APF will not
enhance its operation.  It can only decrease its effectiveness and
reduce APF performance to something already available using existing 
capabilities.

In other words, if you want a filter with less ringing use the 50 Hz
or 100 Hz IIR DSP.  If you want broad peaking with a wider background
use Dual PB.  Use the correct tool for the job: don't try to use graft
a scalpel blade to an axe handle.

73,

... Joe, W4TV

On 11/1/2010 4:24 AM, The Smiths wrote:
>
> Joe,
>
> For some reason you keep thinking that Elecraft's APF is being
designed and programmed by Yaesu engineers Why is it that just
because Yaesu made a mistake with their rig that it means Elecraft has
to destroy THEIR APF just because they choose to add an adjustable Q
control? You have to have confidence that the APF can remain exactly the
same as Lyle and the gang has written it while still adding the ability
to open it up some? Just because Yaesu programmers weren't talented
enough not to destroy what they had built doesn't mean that Elecraft
will make the same mistake.
> Furthermore there are Alpha testers like myself that will make sure
that once the variable Q has been put in that when set to the Minimum
(narrowest) setting that it will still act and feel like it does now. Of
course you too could do the same as an Alfa software tester. This isn't
Yaesu where no one listens to the users once they choose to make a
change or adjustment to the code... Your say WILL matter if things sound
different once the feature has been improved for others. I really don't
think that you're giving Elecraft, it's programmers, or the Alpha
testers such as myself enough credit.
>
> I'm in favor of having a variable Q on this APF system. It will help
improve copy with a tight algorithm that Lyle has written for this one,
while at the same time allowing me to open the Q so that I can copy not
as weak signals with gain, and less ringing. I believe that Lyle will
not destroy his own code by adding a feature that Enhances the operation
of what he's already created for us. If he does, I will be the first to
let him know so he can re-program it.
> The Dual pass band filter is nice, yes, but if you've used your DPB
filter in the K3 you know as well as I do that it acts NOTHING like the
APF with a wider Q in suppressing noise and improving gain as we're
seeing on this current APF. Again, this is NOT a Yaesu rig...
>
>
>
>> Date: Sun, 31 Oct 2010 10:27:33 -0400
>> From: li...@subich.com
>> To: elecraft@mailman.qth.net
>> Subject: Re: [Elecraft] K3 APF Adjustable Q
>>
>>
>>>> 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 us

Re: [Elecraft] K3 APF Adjustable Q

[Robert Harmon]

en it up some? Just because Yaesu programmers weren't talented
> enough not to destroy what they had built doesn't mean that Elecraft
> will make the same mistake.
>> Furthermore there are Alpha testers like myself that will make sure
> that once the variable Q has been put in that when set to the Minimum
> (narrowest) setting that it will still act and feel like it does now. Of
> course you too could do the same as an Alfa software tester. This isn't
> Yaesu where no one listens to the users once they choose to make a
> change or adjustment to the code... Your say WILL matter if things sound
> different once the feature has been improved for others. I really don't
> think that you're giving Elecraft, it's programmers, or the Alpha
> testers such as myself enough credit.
>> 
>> I'm in favor of having a variable Q on this APF system. It will help
> improve copy with a tight algorithm that Lyle has written for this one,
> while at the same time allowing me to open the Q so that I can copy not
> as weak signals with gain, and less ringing. I believe that Lyle will
> not destroy his own code by adding a feature that Enhances the operation
> of what he's already created for us. If he does, I will be the first to
> let him know so he can re-program it.
>> The Dual pass band filter is nice, yes, but if you've used your DPB
> filter in the K3 you know as well as I do that it acts NOTHING like the
> APF with a wider Q in suppressing noise and improving gain as we're
> seeing on this current APF. Again, this is NOT a Yaesu rig...
>> 
>> 
>> 
>>> Date: Sun, 31 Oct 2010 10:27:33 -0400
>>> From: li...@subich.com
>>> To: elecraft@mailman.qth.net
>>> Subject: Re: [Elecraft] K3 APF Adjustable Q
>>> 
>>> 
>>>>> 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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>>>> 
>>>> This list hosted by: http://www.qsl.net
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>>>> 
>>> __
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>>> 
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>>  
> __
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Re: [Elecraft] K3 APF Adjustable Q

[Kok Chen]

On Nov 1, 2010, at 12:53 AM, David Woolley (E.L) wrote:

> Quote para 2, both points:  Reciprocity still applies with respect to gain 
> and off axis effects. 

My mistake.  David is correct on this point.  

Given a constant signal power across the receiving antenna terminals, the SNR 
would be constant no matter what the beam patten is (as long as noise is 
isotropic).  The integrated noise power is constant no matter what the beam 
shape is.

No, this does not mean you should not use a more directive antenna :-).  A more 
directive antenna directed towards the signal will increase the signal power 
while not increasing the noise power.

73
Chen, W7AY



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Re: [Elecraft] K3 APF Adjustable Q [END of Threads]

[Eric Swartz - WA6HHQ, Elecraft]

As per Wayne's last email, we've settled on the initial features of the 
APF and will be putting up a public Beta of the code this week. Stay tuned!

Let's table the discussion of Adjustable Q, and other APF feature 
pro/cons for now in the interest of reducing list email overload for 
others :-)  We'll reopen this once the beta is out.

If you are one of those in the APF alpha test group, feel free to still 
post comments on your use of APF etc.

73,
Eric   WA6HHQ
Elecraft List Moderator

---
Go Giants!
http://sanfrancisco.giants.mlb.com
---

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Re: [Elecraft] K3 APF Adjustable Q [END of Threads]

[Vic K2VCO]

I can't resist this. This weekend I heard a big pileup on 9X0SP but I could 
barely hear 
the 9X station. With the APF he was solid copy. I worked him on the second call 
with my 
100w K3, thanks to these two factors:

1) The APF which let me copy him.

2) The P3, which let me see the signal of the last guy he worked, which was in 
an 
unexpected place. When I called him, my not-so-strong signal was alone and 
right where it 
needed to be!

On 11/1/2010 11:12 AM, Eric Swartz - WA6HHQ, Elecraft wrote:

> If you are one of those in the APF alpha test group, feel free to still
> post comments on your use of APF etc.


-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/
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Re: [Elecraft] K3 APF Adjustable Q [END of Threads]

[Joe Subich, W4TV]

>> I can't resist this. This weekend I heard a big pileup on 9X0SP but
>> I  could barely hear the 9X station. With the APF he was solid copy.

I listened to XV2RZ for quite a while last night on 20 meters.  He was
only an occasional "ping" in the noise without the APF but perfectly
Q5 for well over an hour with the APF engaged.  With my 30 foot high 
Windom and barefoot K3, I did not stand a chance of working him but the
benefit of the existing APF is night and day.

73,

... Joe, W4TV


On 11/1/2010 2:37 PM, Vic K2VCO wrote:
> I can't resist this. This weekend I heard a big pileup on 9X0SP but I could 
> barely hear
> the 9X station. With the APF he was solid copy. I worked him on the second 
> call with my
> 100w K3, thanks to these two factors:
>
> 1) The APF which let me copy him.
>
> 2) The P3, which let me see the signal of the last guy he worked, which was 
> in an
> unexpected place. When I called him, my not-so-strong signal was alone and 
> right where it
> needed to be!
>
> On 11/1/2010 11:12 AM, Eric Swartz - WA6HHQ, Elecraft wrote:
>
>> If you are one of those in the APF alpha test group, feel free to still
>> post comments on your use of APF etc.
>
>
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Re: [Elecraft] K3 APF Adjustable Q [END of Threads]

[Barry]

This is a real problem.  Now I can hear more stations that can't hear me with
my PW signal :.(
Barry W2UP


Joe Subich, W4TV-4 wrote:
> 
> 
> I listened to XV2RZ for quite a while last night on 20 meters.  He was
> only an occasional "ping" in the noise without the APF but perfectly
> Q5 for well over an hour with the APF engaged.  With my 30 foot high 
> Windom and barefoot K3, I did not stand a chance of working him but the
> benefit of the existing APF is night and day.
> 

-- 
View this message in context: 
http://elecraft.365791.n2.nabble.com/K3-APF-Adjustable-Q-tp5688670p5694971.html
Sent from the [K3] mailing list archive at Nabble.com.
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Re: [Elecraft] K3 APF Adjustable Q [END of Threads]

[Gary Gregory]

Barry said

This is a real problem.  Now I can hear more stations that can't hear me
with
my PW signal :.(
Barry W2UP

And soon our favorite Toy Store will have a fix for that problem with the
KPA-500  :-)

Yeay!!!

Gary

On Mon, Nov 1, 2010 at 8:06 PM, Barry  wrote:

>
> This is a real problem.  Now I can hear more stations that can't hear me
> with
> my PW signal :.(
> Barry W2UP
>
>
> Joe Subich, W4TV-4 wrote:
> >
> >
> > I listened to XV2RZ for quite a while last night on 20 meters.  He was
> > only an occasional "ping" in the noise without the APF but perfectly
> > Q5 for well over an hour with the APF engaged.  With my 30 foot high
> > Windom and barefoot K3, I did not stand a chance of working him but the
> > benefit of the existing APF is night and day.
> >
>
> --
> View this message in context:
> http://elecraft.365791.n2.nabble.com/K3-APF-Adjustable-Q-tp5688670p5694971.html
> Sent from the [K3] mailing list archive at Nabble.com.
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>



-- 
Gary
VK4FD - Motorhome Mobile
http://www.qsl.net/vk4fd/
K3 #679, P3 #546
For everything else there's Mastercard!!!
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