K3- Diversity mode cw filter BW ??

[callen1155]

Hello folks.

I'm planning on ordering the second receiver for my K3 soon and have a question.

When using the second receiver in 'diversity mode' and trying to dig out a weak and fading cw signal, what
roofing filter do you find most effective?

I'm assuming in those conditions the narrower the better. I currently have a 400 Hz in my main receiver
and would prefer to just match it with a second 400 Hz for the sub RX.
Also, the 400 seems fine as far as crowded band conditions.

I understand some question this but based on my experience, my ears get a boost of improved (SNR) noise
reduction when the 400 Hz kicks in (as compared to when i only had the 2.7 kHz and narrowed to 400 with
only the DSP). I can't help but wonder if having matching 200 Hz filters would improve copy-ability in diversity mode over the 400 Hz ones?

So when using diversity mode for that weak cw signal, has anyone with both the 200 Hz and 400 Hz filters
noticed any meaningful difference between the two?

thanks for any advice.
chuck
AF4XK

[N5GE-2]

Diversity mode is used to reduce fading on received signals.  Although using
narrow filters to listen to CW signals will improve your ability to hear the
signals, but it will not reduce fading of the signals, as diversity receiving
does very well if your antennas are placed properly.

Diversity receive requires two antennas that are active during RX. This is why
you will install an AUX antenna connection with the sub RX.

Google "diversity receiving" to learn how and why it helps with communications.

Regarding your question about CW filter bandwidth:

I have in the RX and KRX3 identical filters for CW.  1000Hz, 400Hz and 200Hz
(Matched).  If I had it to do again I would choose for CW the 500Hz matched pair
instead of the 400Hz.  I use the 1000Hz very seldom, so I probably would not
have it except for when working split in pileups where I might want to hear more
spectrum where the DX station is Listening.

Amateur Radio Operator N5GE
ARRL Lifetime Member
QCWA Lifetime Member

On Thu, 2 Aug 2012 13:07:30 -0700 (PDT), callen1155 <[hidden email]>
wrote:

>
>Hello folks.
>
>I'm planning on ordering the second receiver for my K3 soon and have a
>question.
>
>When using the second receiver in 'diversity mode' and trying to dig out a
>weak and fading cw signal, what
>roofing filter do you find most effective?
>
>I'm assuming in those conditions the narrower the better. I currently have a
>400 Hz in my main receiver
>and would prefer to just match it with a second 400 Hz for the sub RX.
>Also, the 400 seems fine as far as crowded band conditions.
>
>I understand some question this but based on my experience, my ears get a
>boost of improved (SNR) noise
>reduction when the 400 Hz kicks in (as compared to when i only had the 2.7
>kHz and narrowed to 400 with
>only the DSP). I can't help but wonder if having matching 200 Hz filters
>would improve copy-ability in diversity mode over the 400 Hz ones?
>
>So when using diversity mode for that weak cw signal, has anyone with both
>the 200 Hz and 400 Hz filters
>noticed any meaningful difference between the two?
>
>thanks for any advice.
>chuck
>AF4XK

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