[Elecraft] K4HD Executive Summary Request -- strong signal performance

[Victor Abell]

Thank you for your explanation Wayne.  You are correct; turning off the
noise blanker eliminates wide-band key clicks from strong, wide signals.

Trying to put numbers to your "Aggressive settings of the noise blanker,"
I set about to find the NB level at which the clicks became noticeable.  To
my surprise, for the first strong signal I heard,  I found NB levels of zero
and 25 produced clicks, but a level of 14 did not.  For other strong signals I
heard over the next few days, a NB level of 0 always produced clicks, while
other levels had varying effects.  In the end all I learned  was that NB
levels were mostly unpredictable in how they produced signal artifacts,
except that they almost always did.

Vic, W9RGB

> Message: 10
> Date: Wed, 26 Jan 2022 12:37:48 -0800
> From: Wayne Burdick <n6kr at elecraft.com>
> To: Victor Abell <vabell at lsof.comcastbiz.net>
> Cc: Elecraft Reflector <Elecraft at mailman.qth.net>
> Subject: Re: [Elecraft] K4HD Executive Summary Request -- strong
>         	     signal performance
> Message-ID: <E4FACB3F-2601-4F08-B8EE-46648BE04F70 at elecraft.com>
> Content-Type: text/plain; charset=us-ascii
>
> Aggressive settings of the noise blanker can cause signal artifacts. Make sure the NB is off for any wide band tests.
>
> 73,
> Wayne
> N6KR
>
>> On Jan 26, 2022, at 11:20 AM, Victor Abell <vabell at lsof.comcastbiz.net> wrote:
>> 
>> While I have a K4HD module on order for my K4D (0406) I am also
>> interested in Wayne's comment about strong signal performance.
>> 
>> On the CW bands, particularly 17 meters where I often operate,
>> many times I have observed strong CW signals whose keying causes
>> key clicks to appear some KHz away from their frequency.  For example,
>> the other night a strong signal from W1AW code practice at 18.0975
>> could be copied by its key clicks at 18.079.
>> 
>> I have heard this behavior on other bands -- e.g., 40 and 20 meters --
>> and have reported it to support at elecraft.com, along with videos.
>> So far I haven't heard any explanation for these key clicks.  It could
>> be that I have a flawed K4D or am using some settings that cause it.
>> (I wasn't using either pre-amp when I heard  W1AW's clicks.)
>> 
>> Vic, W9RGB