[Elecraft] K3 Noise Reduction

[Bob McGraw]

Only needs to done once per band unless the noise source really 
changes.   Of course the contest guys are changing bands every 3 
milliseconds, so that might be a chore.

73

Bob, K4TAX

On 12/16/2021 4:19 PM, elecraft-request at mailman.qth.net wrote:
> Message: 8
> Date: Wed, 15 Dec 2021 11:52:54 -0700
> From: David Gilbert<ab7echo at gmail.com>
> To:elecraft at mailman.qth.net
> Subject: Re: [Elecraft] K3 Noise Reduction
> Message-ID:<104029f2-7c47-ebca-3e8b-d3bf3015adf3 at gmail.com>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
>
>
> I applaud the persistence it must have taken you to come up with that
> procedure, but it's actually kind of amusing to think about repeatedly
> doing all of that during a contest.
>
> 73,
> Dave?? AB7E
>
>
>
> On 12/15/2021 9:52 AM, Bob McGraw wrote:
>> The approach I use for the Noise Blanker is this.
>>
>> I first activate the NB and then the Level.?? I start with the DSP OFF
>> and the IF OFF.? I then adjust the DSP value for optimum results
>> without it destroying the quality of the signal.? DO MAKE A NOTE OF
>> THIS VALUE.? Then set the DSP back to OFF.? Then move to the IF and
>> scroll through the settings in an effort to find optimum results.?
>> Once this is done, leave the IF value as determined and return to the
>> DSP and set it to the value previously determined.
>>
>> This works for a given band and given type of noise.? Change bands or
>> noise and do it all again.? There is no ONE setting correct for every
>> condition. ? Right now my 6M noise buzz is S-7 with the NB off.? Then
>> turning it ON and adjusted as above the 6M noise is S-3.? That's 4 S
>> units or 24 dB improvement.? I doubt you will get much better than this.
>>
>> As to Noise Reduction, I find it best performs for CW mode. Again it
>> takes careful adjustment to obtain optimum results.?? I don't use NR
>> for SSB signals. I prefer to adjust the Attenuation value and the RF
>> Gain to produce optimum results when operating SSB.?? I find optimum
>> results occur when the no signal band noise is about 10 dB above the
>> receiver noise floor.?? In order to accomplish this operating point,
>> one will need to use ATTENUATION and RF Gain reduction.?? More gain
>> won't aid in receiving weak signals, but just the opposite, as the
>> signal will pop out of the noise.
>>
>> I generally find using either NB or NR, but not both, is the better
>> way to operate.? I doubt there is anything wrong with your radio.?
>> Most likely the result is more related to receiver setting parameters.
>>
>> 73
>>
>> Bob, K4TAX