[KX3] How to use manual notch in SSB mode

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[KX3] How to use manual notch in SSB mode

WD4SDC
Greetings.

You *can* use manual notch on SSB on the KX3.

Turns out that if you turn on the manual notch while in CW mode that it will stay on if you switch to SSB without cycling thru a mode that cancels it - such as FM or data modes.  

Here's an example of how I did it.
Starting with LSB mode:

A->B
MODE -> CW
FC -> +0.92
BW=2.8KHz
RIT=-700Hz This removes (my) pitch offset and opens the bandwidth to receive LSB voice.

Now you can turn on the notch filter and adjust to remove CW RFI.
Press A/B and turn off RIT to have SSB with manual notch enabled - and CW removed!  A/B allows me to go from CW to SSB w/o cycling thru FM, although I could also disable FM mode.

For USB, you would need to use CWR and RIT=+700Hz.

Why this is desirable:
The auto-notch feature is great for intermittent tuneups or other (multiple) CW signals in the SSB passband, but it is applied after the AGC, so if the CW signal is much stronger than the voice signal, the voice signal is suppressed even though the tone is removed - like when trying to copy an S3 voice with a S9+20 CW sitting on it.

For strong "persistent" CW QRM, using the manual notch removes the CW signal *before* the AGC, allowing AGC to operate on the desired signal.  This notch is at least 80dB!  The S9+20dB CW goes away, and S3 is perfectly readable! Very cool! Especially useful if the CW signal is in the 500-1500Hz range - making it difficult to remove with low or high pass BW adjustment and still copy voice - you can, but it takes effort.

I tried creating a macro for this - it kinda works.

MD3;SWH20;MD1;

Works, but the macro name covers up the notch frequency display in the VFOB area.  You *can* adjust the notch frequency even though you already in SSB mode (if you turn the knob within the 2 sec window), but it's a blind adjustment.  And then the macro name sticks until you do something to update the VFOB display (like adjust BW). If you just send the commands using the KX3 utility program, it works great, but you need a pc :\.  Perhaps there is a macro work-around?

73
Steve
WD4SDC
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Re: [KX3] How to use manual notch in SSB mode

GM4JJJ
Thanks for that workaround Steve, I must give it a try here.

I can't understand why Elecraft don't give us the option of manual notch on SSB on the KX3, as I find the auto notch doesn't always lock onto weak but annoying heterodynes but could be easily notched out manually.  

73 from David GM4JJJ

> On 4 Mar 2016, at 05:33, WD4SDC <[hidden email]> wrote:
>
> Greetings.
>
> You *can* use manual notch on SSB on the KX3.
>
> Turns out that if you turn on the manual notch while in CW mode that it will
> stay on if you switch to SSB without cycling thru a mode that cancels it -
> such as FM or data modes.  
>
> Here's an example of how I did it.
> Starting with LSB mode:
>
> A->B
> MODE -> CW
> FC -> +0.92
> BW=2.8KHz
> RIT=-700Hz    This removes (my) pitch offset and opens the bandwidth to receive
> LSB voice.
>
> Now you can turn on the notch filter and adjust to remove CW RFI.
> Press A/B and turn off RIT to have SSB with manual notch enabled - and CW
> removed!  A/B allows me to go from CW to SSB w/o cycling thru FM, although I
> could also disable FM mode.
>
> For USB, you would need to use CWR and RIT=+700Hz.
>
> Why this is desirable:
> The auto-notch feature is great for intermittent tuneups or other (multiple)
> CW signals in the SSB passband, but it is applied after the AGC, so if the
> CW signal is much stronger than the voice signal, the voice signal is
> suppressed even though the tone is removed - like when trying to copy an S3
> voice with a S9+20 CW sitting on it.
>
> For strong "persistent" CW QRM, using the manual notch removes the CW signal
> *before* the AGC, allowing AGC to operate on the desired signal.  This notch
> is at least 80dB!  The S9+20dB CW goes away, and S3 is perfectly readable!
> Very cool! Especially useful if the CW signal is in the 500-1500Hz range -
> making it difficult to remove with low or high pass BW adjustment and still
> copy voice - you can, but it takes effort.
>
> I tried creating a macro for this - it kinda works.
>
> MD3;SWH20;MD1;
>
> Works, but the macro name covers up the notch frequency display in the VFOB
> area.  You *can* adjust the notch frequency even though you already in SSB
> mode (if you turn the knob within the 2 sec window), but it's a blind
> adjustment.  And then the macro name sticks until you do something to update
> the VFOB display (like adjust BW). If you just send the commands using the
> KX3 utility program, it works great, but you need a pc :\.  Perhaps there is
> a macro work-around?
>
> 73
> Steve
> WD4SDC
>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/KX3-How-to-use-manual-notch-in-SSB-mode-tp7614894.html
> Sent from the Elecraft mailing list archive at Nabble.com.
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