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KX2 Filter Bandwidth issue

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Corky

KX2 Filter Bandwidth issue

I have been using my KX2 for digital (Fldigi and SignaLink) and am seeing a very strange behavior when I attempt to adjust the signal bandwidth. As long as the bandwidth is above 2.0 everything works fine. When I reduce it to cut out nearby signals the signal on the fldigi waterfall has s gap in the middle and two bands, one above and the other below where I am listening. This cleverly filters out the exact signal I am trying to monitor and leaves the signals above and below my 1500 Hz operating point still coming through. I have not found any way to fix this, and the same settings on either the KX3 or the K2 produce the expected results of a single narrowed band around my monitoring point.

Anyone else experienced this or have any suggestions as to how to get the desired/expected results when adjusting the receive bandwidth?

Thanks and 73,
-Corky, AF4PM
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ve3ibw

Re: KX2 Filter Bandwidth issue

First thing that comes to mind, is the notch filter on?

Regards
Brian
VE3IBW

On Wed, Jan 16, 2019 at 10:08 AM Corky <[hidden email]> wrote:

> I have been using my KX2 for digital (Fldigi and SignaLink) and am seeing
> a very strange behavior when I attempt to adjust the signal bandwidth. As
> long as the bandwidth is above 2.0 everything works fine. When I reduce it
> to cut out nearby signals the signal on the fldigi waterfall has s gap in
> the middle and two bands, one above and the other below where I am
> listening. This cleverly filters out the exact signal I am trying to
> monitor and leaves the signals above and below my 1500 Hz operating point
> still coming through. I have not found any way to fix this, and the same
> settings on either the KX3 or the K2 produce the expected results of a
> single narrowed band around my monitoring point.
>
> Anyone else experienced this or have any suggestions as to how to get the
> desired/expected results when adjusting the receive bandwidth?
>
> Thanks and 73,
> -Corky, AF4PM
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

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Regards,
Brian
VE3IBW

Lyle Johnson

Re: KX2 Filter Bandwidth issue

In reply to this post by Corky

Is the mode DATA A or USB/LSB? Is USB/LSB (voice SSB) this is normal
behavior as the radio switches to "3rd method" demodulation. DATA A
should not have this behavior.

73,

Lyle KK7P

On 1/16/19 11:06 AM, Corky wrote:
> I have been using my KX2 for digital (Fldigi and SignaLink) and am seeing a very strange behavior when I attempt to adjust the signal bandwidth. As long as the bandwidth is above 2.0 everything works fine. When I reduce it to cut out nearby signals the signal on the fldigi waterfall has s gap in the middle and two bands, one above and the other below where I am listening.
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Corky

Re: KX2 Filter Bandwidth issue - Resolved

In reply to this post by Corky

I reviewed everything (displays and filter settings) and everything looked to be fine, but it was still behaving strangely. As a last attempt, with system set to Data A (as it was previously) I engaged the filter adjust mode and then use the dial to set "norm" for the mode. All of a sudden it worked as expected! So I am not sure what was funky - perhaps vestiges of a previous RTTY setup or something, but now is working fine.

Thanks and 73,
-Corky, AF4PM

On Wed, Jan 16, 2019, at 10:33 AM, Carl wrote:

> Corky,
>
> It sounds like you are in APF-AN mode, like in holding the FIL button
> too long. I can adjust the width and move the bandpass around OK. Other
> than that, maybe the software is doing something. I don't have FLDigi.
> Is the display correct, like on page 12 or like on page 18? Are you in
> Data A mode?
>
> Good luck, hope this helped you.
>
> --
> Carl
> AB1DD
> Resistance is futile.
> (don't know about reactance, though)
>
>

Bob McGraw - K4TAX

Re: KX2 Filter Bandwidth issue - Resolved

I have experienced issues where a computer and the application software
left fragments of data in the radio. Not specific to the KX2 but could
be. From your description it seems the radio was in FSK mode. That
performs as you described which is a function of APF.

I have found in most cases it is best to close the software application
before turning off the radio. Then turn off the radio and then shut
down the power supply, then shut down the computer. Power up in the
reverse sequence; computer completely booted, power supply on, turn on
the radio, then load / open the application software.

One other issue which has been shown to leave corrupt data in the radio
is when the power supply is shut down before the radio is turned off.
The radio has no chance to save any recent data or configuration.
Always turn off the radio first and then the power supply.

73

Bob, K4TAX

On 1/16/2019 5:07 PM, Corky wrote:
> I reviewed everything (displays and filter settings) and everything looked to be fine, but it was still behaving strangely. As a last attempt, with system set to Data A (as it was previously) I engaged the filter adjust mode and then use the dial to set "norm" for the mode. All of a sudden it worked as expected! So I am not sure what was funky - perhaps vestiges of a previous RTTY setup or something, but now is working fine.
>
> Thanks and 73,
> -Corky, AF4PM
>

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