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Hardware Noise Blanker on the K3

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Tobyp

Hardware Noise Blanker on the K3

Someone with power line noise.......does the hardware noise blanker work very well on s9 power line noise. IF so, is the SSB signal distorted ? DSP blankers work to some extent but distort the audio.

Toby W4CAK
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HarrytheHam

Re: Hardware Noise Blanker on the K3

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Charles Johnson-2-3

Re: Hardware Noise Blanker on the K3

In reply to this post by Tobyp

It works better than any noise blanker I've ever used on any other radio.

73, Charlie

On 6/13/2010 21:41, Toby Pennington wrote:

> Someone with power line noise.......does the hardware noise blanker work very well on s9 power line noise. IF so, is the SSB signal distorted ? DSP blankers work to some extent but distort the audio.
>
> Toby W4CAK
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>

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k5oai

Re: Hardware Noise Blanker on the K3

I have a S9+10 noise that I am fighting on all bands, it's temp related, as the
day goes over (90-93 degrees it turns on) I will finally shut down about 3 hrs
after sunset... but I digress

I sold my TS-450SAT which couldn't do much with it, you might see the S-meter
drop a needles width from 9+10 to 9+9 big deal.

With my K3, by playing with *both* the Noise DSP as well as the hardware noise
blankers,
I can see the noise floor drop from 9+10 to maybe S8,
however with the terrible bands of late,
and my apartment dweller antennas sometimes isn't low enough,
for me to hear some signals.

But hey it's one heck of a lot better than any other rig I ever used.
There are 18 different hardware settings, in combination with 18 DSP Noise
variations, did I mention the plain DSP settings add another 24 possibilities?

Sometimes it's not enough. Sometimes it's great, just depends on which noise you
are dealing with.

Oh, and yes, with the most aggressive settings, my neighbor's 9+30 signals do
distort somewhat, whatcha gonna do? Find another hobby? Na, I just work around
the loudest times of day. shrug

On 6/13/2010 8:50 PM, Charles Johnson wrote:
> It works better than any noise blanker I've ever used on any other radio.
>
snip
> On 6/13/2010 21:41, Toby Pennington wrote:
>> Someone with power line noise.......does the hardware noise blanker work
>> very well on s9 power line noise. IF so, is the SSB signal distorted ?
>> DSP blankers work to some extent but distort the audio.
>>

--
GB & 73
K5OAI
Sam Morgan
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juergen piezo

Re: Hardware Noise Blanker on the K3

In reply to this post by Tobyp

Hi Toby

Frankly the hardware noise blanker on the K3 is mostly useless.

I dont really dont even know if its "analog" in nature. I have compared it to many other analog blankers on other radios, if it does work its barely perceptible.

I must have a faulty analog blanker. The way people speak about how well it works i just dont see in practice. I have 2 k3's and have used my clubs K3's and they are all the same. All i seem to hear is distortion and no blanking effect.

The DSP noise blanker on the K3 is a different story. On any of the number 7 settings it will take care of most power line noise. I find that you really need to use the 7 setting even for mild power line noise. On true analog noise blankers you could take out mild power line noise without aggressive settings which just cause distortion. The K3's DSp noise blanker is impressive even with all the distortion, so yes it does "work"

If you do have a radio from the past that works in your location I would suggest you keep it. That is what I have done, I have radios here that I use on the low bands that beat the K3's DSP blanker and they just conventional analog blankers. The big advantage is that I can use these blankers on low settings and still have a "decent" receiver without distortion.

Noise blankers on radios have always been luck of the draw. I know of several people who have changed radios for nothing more than good noise blanker performance. These days operating anywhere in big cities you really need a decent noise blanker.

John

--- On Sun, 6/13/10, Toby Pennington <[hidden email]> wrote:

> From: Toby Pennington <[hidden email]>
> Subject: [Elecraft] Hardware Noise Blanker on the K3
> To: [hidden email]
> Date: Sunday, June 13, 2010, 6:41 PM
> Someone with power line
> noise.......does the hardware noise blanker work very well
> on s9 power line noise. IF so, is the SSB signal
> distorted ? DSP blankers work to some extent but
> distort the audio.
>
> Toby W4CAK
> ______________________________________________________________
> 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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Guy, K2AV

Re: Hardware Noise Blanker on the K3

The hardware (IF in the NB LEVEL display) blanker is analog, and works
the same as blankers in analog receivers for decades. But it takes
high impulse very short spikes to drive it. An analog blanker will
always cause some degree of "distortion", description of said
"distortion" always particular to the hearer. Not just K3, any
classic analog blanker. The circuit is modulating the IF with what
amounts to a square wave pulse. Noteworthy in use of these is splatter
from other loud signals in the IF stage which has the blanker.

>From time to time on the lower bands, I have my hide-and-seek 13kV
power line buzz. The IF blanker works well on this for me as long as
it's not a contest. I drop back to the DSP blanking in a contest, but
without all the loud signals to splatter the IF blanker, the IF is a
tad better. On the other hand, I have this AC related growl/buzz on 6
meters which the IF blanker won't touch at all. DSP blanking t2-7 or
t3-7 gets it nicely.

The DSP blanker is the future. It's code. It can be worked on,
improved, and have new ideas added to it.

Oh, and one other thing, running the RF gain wide open on lowbands
with PRE on, or not using ATT when you should, is the enemy of the
blankers. Engaging the ADC defense hardware AGC by smash-mouthing RF
gain/PRE/ATT settings mushes blanker effectiveness.

73, Guy.

On Sun, Jun 13, 2010 at 10:15 PM, juergen <[hidden email]> wrote:

> Hi Toby
>
> Frankly the hardware noise blanker on the K3 is mostly useless.
>
> I dont really dont even know if its "analog" in nature. I have compared it to many other analog blankers on other radios, if it does work its barely perceptible.
>
> I must have a faulty analog blanker. The way people speak about how well it works i just dont see in practice. I have 2 k3's and have used my clubs K3's and they are all the same. All i seem to hear is distortion and no blanking effect.
>
>
> The DSP noise blanker on the K3 is a different story. On any of the number 7 settings it will take care of most power line noise. I find that you really need to use the 7 setting even for mild power line noise. On true analog noise blankers you could take out mild power line noise without aggressive settings which just cause distortion. The K3's DSp noise blanker is impressive even with all the distortion, so yes it does "work"
>
> If you do have a radio from the past that works in your location I would suggest you keep it. That is what I have done, I have radios here that I use on the low bands that beat the K3's DSP blanker and they just conventional analog blankers. The big advantage is that I can use these blankers on low settings and still have a "decent" receiver without distortion.
>
>
> Noise blankers on radios have always been luck of the draw. I know of several people who have changed radios for nothing more than good noise blanker performance. These days operating anywhere in big cities you really need a decent noise blanker.
>
>
> John
>
>
> --- On Sun, 6/13/10, Toby Pennington <[hidden email]> wrote:
>
>> From: Toby Pennington <[hidden email]>
>> Subject: [Elecraft] Hardware Noise Blanker on the K3
>> To: [hidden email]
>> Date: Sunday, June 13, 2010, 6:41 PM
>> Someone with power line
>> noise.......does the hardware noise blanker work very well
>> on s9 power line noise. IF so, is the SSB signal
>> distorted ? DSP blankers work to some extent but
>> distort the audio.
>>
>> Toby W4CAK
>> ______________________________________________________________
>> 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
>>
>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
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n7ws

Re: Hardware Noise Blanker on the K3

In reply to this post by Tobyp

You are asking a question for which there is no good answer.

"Power line noise" can look almost like anything from an occasional pop when a piece of hardware moves, to full blown partial discharge (commonly called corona) that is continuous in nature.

Rather than discuss the nature of hardware blankers here, allow me to refer you with no modesty whatsoever, to a paper I wrote a long time ago. http://k6mhe.com/n7ws/Noise_Blanker.pdf

This is a 35-year-old design and time marches on, but the principles haven't changed.

In monopulse radar receivers, where the i-f is blanked during each transmitter pulse, and there are multiple i-f amplifiers that have to track in both phase and gain, we went to heroic efforts to design blanking gates that operated gracefully without a lot of blanking transient
feed-through. This stuff isn't trivial.

I haven't found that the K3 hardware blanker is particularly effective most of the time and at the wider settings it is susceptible to overload on big signals, but that is the nature of the beast. I will give it credit for being superior to the one in my TS-870 which is totally useless and a waste of a front panel push button, but that is damning with faint praise.

It's interesting that the best noise blanker in any commercial radio I've owned was in an old analog Yaesu FT221 two-meter multi-mode. I don't know how they did it, but they did something right.

Wes N7WS

--- On Sun, 6/13/10, Toby Pennington <[hidden email]> wrote:

From: Toby Pennington <[hidden email]>
Subject: [Elecraft] Hardware Noise Blanker on the K3
To:
[hidden email]
Date: Sunday, June 13, 2010, 7:41 PM

Someone with power line noise.......does the hardware noise blanker work very well on s9 power line noise. IF so, is the SSB signal distorted ? DSP blankers work to some extent but distort the audio.

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