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K3: Real world use of 1.8 filter (oops)

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DOUGLAS ZWIEBEL

K3: Real world use of 1.8 filter (oops)

I would like to change one word in the following paragraph. In the
last sentence, "If the SSB band..." change the word " If " to " Unless
"

Sorry about that.

de Doug KR2Q

I have to wonder out loud how many guys are "feeling" the DSP filter
width impact when they go from their 2.7 to 2.1 to 1.8 on SSB versus
how much of that is improvement in IMD reduction specs. For 99%, they
probably are "feeling" the narrower DSP filter impact (which means the
narrower roofing filter has essentially no impact at all). If the SSB
band is packed with wall-to-wall very, very, very strong signals, then
I'm betting that the roofing filter BW just won't matter for the vast
majority of ops.
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Keith Heimbold

Re: K3: Real world use of 1.8 filter (oops)

I will roll with the current setup for awhile but i have seen on several occasions how I can deploy the use of the 2.1 kHz filter in noisier band conditions say on 40m to improve intelligibility and readability of weaker signals.

If the 1.8 kHz filter will continue in that line of improvement, it would probably be warranted down the road to add the 1.8 khz filter and reconfigure my current setup on this K3. I do have to hold off for more spending on the radio since I focusing my green stamps on a SteppIR 3 element antenna upgrade project and my wife wants an incredibly expensive baby room for our first.

Keith
AG6AZ

Sent from my iPhone please excuse typos

On Jan 14, 2012, at 6:28 AM, "DOUGLAS ZWIEBEL" <[hidden email]> wrote:

> I would like to change one word in the following paragraph. In the
> last sentence, "If the SSB band..." change the word " If " to " Unless
> "
>
> Sorry about that.
>
> de Doug KR2Q
>
> I have to wonder out loud how many guys are "feeling" the DSP filter
> width impact when they go from their 2.7 to 2.1 to 1.8 on SSB versus
> how much of that is improvement in IMD reduction specs. For 99%, they
> probably are "feeling" the narrower DSP filter impact (which means the
> narrower roofing filter has essentially no impact at all). If the SSB
> band is packed with wall-to-wall very, very, very strong signals, then
> I'm betting that the roofing filter BW just won't matter for the vast
> majority of ops.
> ______________________________________________________________
> 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

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Matt Zilmer

Re: K3: Real world use of 1.8 filter (oops)

In reply to this post by DOUGLAS ZWIEBEL

Not sure what you mean by "feeling". As the filter BW is narrowed, I
usually shift the Fc down as well. This gives more balance to the
heard spectrum, which is a change of course. When the roofing filter
shifts from 2.8 to 1.8, I can't "feel" a transition, maybe because of
this operating method.

The only way I've really ever perceived a transition is when using the
XFIL key to change roofing filter. The transition is abrupt, as
expected.

I notice a reduction in distortion using the 1.8 filter in crowded
conditions. Seems like most folks would notice better
intelligibility, but can't really sense distortion as such. Contesters
excluded, of course. They can and do notice.

I feel a lot more IMD reduction in CW, while changing the DSP filter
bandwidth. Much more.

Filters here: 0.25, 1.8, 2.8, 6.0, 13.0.

73,
matt W6NIA

On Sat, 14 Jan 2012 09:28:00 -0500, you wrote:

>I would like to change one word in the following paragraph. In the
>last sentence, "If the SSB band..." change the word " If " to " Unless
>"
>
>Sorry about that.
>
>de Doug KR2Q
>
>I have to wonder out loud how many guys are "feeling" the DSP filter
>width impact when they go from their 2.7 to 2.1 to 1.8 on SSB versus
>how much of that is improvement in IMD reduction specs. For 99%, they
>probably are "feeling" the narrower DSP filter impact (which means the
>narrower roofing filter has essentially no impact at all). If the SSB
>band is packed with wall-to-wall very, very, very strong signals, then
>I'm betting that the roofing filter BW just won't matter for the vast
>majority of ops.
>______________________________________________________________
>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