Elecraft › [K3]

Noise Blankers

Classic

List

Threaded

6 messages Options

Tom Bickley

Noise Blankers

I'm overdue for a new radio (at least, that's what I am telling my
XYL). In considering the purchase, unfortunately one of the major
considerations I must take into account is
the noise blanker function. I have recently moved to an area with A LOT
of power line noise. I have high voltage lines around my immediate QTH.
It is a constant S3 to S5 on all bands above 7 MHz and, sometimes on
really
cold mornings, a seperate, additional noise kicks in that takes it to
S9 or more. I am trying to locate these noise sources but have been
unable to so far. I must run the noise blanker on my old TS-850s at all times to help me manage this problem. With the NB engaged (which
is 'always') I have audio distortion created from nearby signals,
especially stronger signals within 30
kc's of my receive frequency, no matter at what level I run either of the noise
blankers.

I would like to hear from K3 owners who might have
'line noise problems' and know how the noise blanker in your K3 handles
the problem.

Mni Tnx / 73 > K4NA

_________________________________________________________________
Hotmail: Powerful Free email with security by Microsoft.
http://clk.atdmt.com/GBL/go/196390710/direct/01/
______________________________________________________________
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

wayne burdick

Re: Noise Blankers

Administrator

Hi Tom,

You'll get a lot of opinions on noise blankers, I suspect :)

Here's my 2 cents: The K3's combination of two noise blankers -- one
at the 1st IF and one at the DSP -- can work wonders on all sorts of
noise. But it's especially good with power-line noise (loads of that
at my QTH). The K3 doesn't pre-filter down to 15 kHz, which means the
sharp pulse rise-times are preseved. This means you can typically keep
the IF blanker's threshold very high, minimizing the type of IMD that
all IF blankers cause. The DSP blanker is icing on the cake,
especially if you also have complex noise like that from switching
supplies, etc. (stuff that drifts a lot).

That said, I suggest you borrow a K3 and try it at your QTH. We can
find a nearby K3 owner for you, or you can ask on the reflector.

Good luck with whatever rig you choose, and don't hesitate to post
further questions.

73,
Wayne
N6KR

On Jan 6, 2010, at 5:38 PM, Tom Bickley wrote:

>
> I'm overdue for a new radio (at least, that's what I am telling my
> XYL). In considering the purchase, unfortunately one of the major
> considerations I must take into account is
> the noise blanker function. I have recently moved to an area with A
> LOT
> of power line noise. I have high voltage lines around my immediate
> QTH.
> It is a constant S3 to S5 on all bands above 7 MHz and, sometimes on
> really
> cold mornings, a seperate, additional noise kicks in that takes it to
> S9 or more. I am trying to locate these noise sources but have been
> unable to so far. I must run the noise blanker on my old TS-850s at
> all times to help me manage this problem. With the NB engaged (which
> is 'always') I have audio distortion created from nearby signals,
> especially stronger signals within 30
> kc's of my receive frequency, no matter at what level I run either
> of the noise
> blankers.
>
> I would like to hear from K3 owners who might have
> 'line noise problems' and know how the noise blanker in your K3
> handles
> the problem.
>
> Mni Tnx / 73 > K4NA
>
> _________________________________________________________________
> Hotmail: Powerful Free email with security by Microsoft.
> http://clk.atdmt.com/GBL/go/196390710/direct/01/
> ______________________________________________________________
> 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
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

Dunc Carter - W5DC

Re: Noise Blankers

In reply to this post by Tom Bickley

The K3 blankers have a considerable range of adjustability of both the
blanking threshold with seven steps, and the blanking pulse width with
three steps, with independent settings for hardware blanking and dsp
blanking. Hopefully, you can find a setting that will work without
excess distortion but that may not always be the case if the noise is
relatively low and the inband signals are not. There is a learning
curve. Blanker effectiveness was one of my criteria for selecting the K3.

73, Dunc, W5DC

Tom Bickley wrote:

> I'm overdue for a new radio (at least, that's what I am telling my
> XYL). In considering the purchase, unfortunately one of the major
> considerations I must take into account is
> the noise blanker function. I have recently moved to an area with A LOT
> of power line noise. I have high voltage lines around my immediate QTH.
> It is a constant S3 to S5 on all bands above 7 MHz and, sometimes on
> really
> cold mornings, a seperate, additional noise kicks in that takes it to
> S9 or more. I am trying to locate these noise sources but have been
> unable to so far. I must run the noise blanker on my old TS-850s at all times to help me manage this problem. With the NB engaged (which
> is 'always') I have audio distortion created from nearby signals,
> especially stronger signals within 30
> kc's of my receive frequency, no matter at what level I run either of the noise
> blankers.
>
> I would like to hear from K3 owners who might have
> 'line noise problems' and know how the noise blanker in your K3 handles
> the problem.
>
> Mni Tnx / 73 > K4NA
>
> _________________________________________________________________
> Hotmail: Powerful Free email with security by Microsoft.
> http://clk.atdmt.com/GBL/go/196390710/direct/01/
> ______________________________________________________________
> 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
>
>

Matt Zilmer

Re: Noise Blankers

In reply to this post by Tom Bickley

Hi Tom,

Well, I have a K3 noise blanker story for you.

About two months ago, I suddenly had an S9+20 line noise problem
around here. I knew it was some type of failed Edison equipment, or
maybe something at a residence. It was loud enough to hear with a
stubby for ANT1, and on 80m through 30m under any conditions.

I had to diddle the K3's noise blanker a bit to get it dialed in
right, but I finally killed the crud on the Main and Sub receivers.
There was a residual amount of distortion; I had never run the NB
this aggressively before - never had to. However, effectively the
noise was blanked down to S7 or so on 40m where it was the worst. And
it made 80m usable again on CW...

In a few days, an Edison power quality tech came out and located the
noise source. Some customer-owned (but unused) transformers on a
citrus farm a few blocks from us had open primaries. He had the feed
to them disconnected and notified the owner that they needed to be
replaced (they weren't working anyway). These transformers were used
to power irrigation pumps, so the owner got the problem cleared up
right away.

I was completely amazed how well the NB works under very difficult
conditions. May no one else have to find out how well this feature
works in the same way or for a similar reason.

73,
matt W6NIA
K3 #24
K2 #2810

Except for being a paying customer, I have no formal affiliation with
Elecraft.

On Thu, 07 Jan 2010 01:38:35 +0000, you wrote:

>
>I'm overdue for a new radio (at least, that's what I am telling my
>XYL). In considering the purchase, unfortunately one of the major
>considerations I must take into account is
>the noise blanker function. I have recently moved to an area with A LOT
>of power line noise. I have high voltage lines around my immediate QTH.
>It is a constant S3 to S5 on all bands above 7 MHz and, sometimes on
>really
>cold mornings, a seperate, additional noise kicks in that takes it to
>S9 or more. I am trying to locate these noise sources but have been
>unable to so far. I must run the noise blanker on my old TS-850s at all times to help me manage this problem. With the NB engaged (which
>is 'always') I have audio distortion created from nearby signals,
>especially stronger signals within 30
>kc's of my receive frequency, no matter at what level I run either of the noise
>blankers.
>
>I would like to hear from K3 owners who might have
>'line noise problems' and know how the noise blanker in your K3 handles
>the problem.
>
>Mni Tnx / 73 > K4NA
>
>_________________________________________________________________
>Hotmail: Powerful Free email with security by Microsoft.
>http://clk.atdmt.com/GBL/go/196390710/direct/01/
>______________________________________________________________
>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

Mike Reublin

Re: Noise Blankers

In reply to this post by Tom Bickley

Tom,
I'm a new K3 owner, coming from an ICOM PRO II, and still learning how
to use the K3. I live with a pretty constant S9 or better noise level. I
think most of it is power line.

Whatever it is, the NB on the K3 knocks the cover off the ICOM.

73, Mike NF4L

Tom Bickley wrote:

David Olean

Re: Noise Blankers

In reply to this post by Tom Bickley

Hello Tom,
I am plagued by excessive amounts of power line noise on 50, 144 and
222MHz. It has been going on for years to the point where the FCC (both
Riley Hollingsworth and Laura Smith) have sent letters to the local utility.
I have used several receivers and none really took out the noise as
effectively as the K3 has. I find that for my situation, the DSP blanker is
quite good when things get bad. In the past I have seen other noise
blankers get swamped out by so many noise pulses that they have lost
effectiveness. Simple noises of maybe one or two arcing points can be
removed, but 7 or 8 is another story. As more noise comes on, the blankers
fare more poorly. (Yes, one power pole can have 7 or 8 points that are
generating rfi) With the K3, I have been able to negate most of the noise
and still am able to operate through the noise by adjusting the DSP NR
settings along with IF blanking. I find that the DSP NR works better for my
situation. My antennas are high and in the clear. The worst noise problem
has come from a 34.5 KV line that is seven miles from my antenna. It is
typically peaking S7 and is composed of many arcing tie wires and leaking
insulators. Only the K3 has removed this noise as a factor in receiving. My
other radios with only IF blanking do absolutely nothing to the noise in
that direction.
The nice thing is that you can tailor the effect on the fly and
immediately tell which setting works best. I am pleased with the DSP as it
does not overload with strong signals. While it makes the audio sound
somewhat ugly at aggressive settings, the overall outcome is positive. I am
more than happy with the noise performance of the K3. It is quite a tool. I
believe the Flex Radio is another stellar performer in this area, but I have
not tried it at my QTH.

Dave K1WHS

----- Original Message -----
From: "Tom Bickley" <[hidden email]>
To: <[hidden email]>
Sent: Thursday, January 07, 2010 1:38 AM
Subject: [Elecraft] Noise Blankers

>
> I'm overdue for a new radio (at least, that's what I am telling my
> XYL). In considering the purchase, unfortunately one of the major
> considerations I must take into account is
> the noise blanker function. I have recently moved to an area with A LOT
> of power line noise. I have high voltage lines around my immediate QTH.
> It is a constant S3 to S5 on all bands above 7 MHz and, sometimes on
> really
> cold mornings, a seperate, additional noise kicks in that takes it to
> S9 or more. I am trying to locate these noise sources but have been
> unable to so far. I must run the noise blanker on my old TS-850s at all
> times to help me manage this problem. With the NB engaged (which
> is 'always') I have audio distortion created from nearby signals,
> especially stronger signals within 30
> kc's of my receive frequency, no matter at what level I run either of the
> noise
> blankers.
>
> I would like to hear from K3 owners who might have
> 'line noise problems' and know how the noise blanker in your K3 handles
> the problem.
>
> Mni Tnx / 73 > K4NA
>
> _________________________________________________________________
> Hotmail: Powerful Free email with security by Microsoft.
> http://clk.atdmt.com/GBL/go/196390710/direct/01/
> ______________________________________________________________
> 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