Elecraft

K2 noise blanker

Classic

List

Threaded

7 messages Options

Brett Gazdzinski

K2 noise blanker

I have tried it on various types of noises, some which sounded like auto
ignition noise, I think someone had something running without resistor wires
or plugs, strong and weak signals, no change.
I did have a bad street light out front of my house, the reason I got the
NB, but they fixed it before I got the noise blanker.

The main reason I asked was there seems to be no degradation of signals with
the NB on at any setting.
On most rigs, you can hear a difference, and where its adjustable, it makes
things sound really bad when you turn it up. The pro 3 is like that.

On the K2, I have been unable to detect it doing anything at all, any mode,
any noise, although the noise level I usually have is not bad.

Thanks for the replies,
Brett
N2DTS

______________________________________________________________
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

Joe Planisky

Re: K2 noise blanker

Hi Brett,

Last summer, I had similar questions about the KNB2 in my K2. In my
case, a neighbor had put up a new electric fence and I was getting QRM
in the form of a pulse every second. The unmodified KNB2 seemed to
have little to no effect on the noise. In fact, I questioned whether
it was working at all. A 'scrape test' (connecting a wire to the
antenna connector and scraping it on some metal surface in the shack
to generate static) indicated that it was indeed working.

The modification described here

http://www.dl7maj.de/KNB2-Mod.pdf

seemed to improve the situation. After making the mod described, the
KNB2 would partially take out the electric fence noise using the LEVEL
LOW threshold. Not perfect, but better than it was.

You can read the original thread by searching the list archives for
the topic "[K2] KNB2 vs. electric fence" that started on August 3, 2008.

73
--
Joe KB8AP

On Mar 1, 2009, at 2:18 PM, Brett Gazdzinski wrote:

> I have tried it on various types of noises, some which sounded like
> auto
> ignition noise, I think someone had something running without
> resistor wires
> or plugs, strong and weak signals, no change.
> I did have a bad street light out front of my house, the reason I
> got the
> NB, but they fixed it before I got the noise blanker.
>
> The main reason I asked was there seems to be no degradation of
> signals with
> the NB on at any setting.
> On most rigs, you can hear a difference, and where its adjustable,
> it makes
> things sound really bad when you turn it up. The pro 3 is like that.
>
> On the K2, I have been unable to detect it doing anything at all,
> any mode,
> any noise, although the noise level I usually have is not bad.
>
> Thanks for the replies,
> Brett
> N2DTS
>

______________________________________________________________
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

Brett Gazdzinski

Re: K2 noise blanker

Joe,
I will try this, thanks!

Brett
N2DTS

----- Original Message -----
From: "Joe Planisky" <[hidden email]>
To: "Brett Gazdzinski" <[hidden email]>
Cc: <[hidden email]>
Sent: Sunday, March 01, 2009 6:03 PM
Subject: Re: [Elecraft] K2 noise blanker

> Hi Brett,
>
> Last summer, I had similar questions about the KNB2 in my K2. In my
> case, a neighbor had put up a new electric fence and I was getting QRM
> in the form of a pulse every second. The unmodified KNB2 seemed to
> have little to no effect on the noise. In fact, I questioned whether
> it was working at all. A 'scrape test' (connecting a wire to the
> antenna connector and scraping it on some metal surface in the shack
> to generate static) indicated that it was indeed working.
>
> The modification described here
>
> http://www.dl7maj.de/KNB2-Mod.pdf
>
> seemed to improve the situation. After making the mod described, the
> KNB2 would partially take out the electric fence noise using the LEVEL
> LOW threshold. Not perfect, but better than it was.
>
> You can read the original thread by searching the list archives for
> the topic "[K2] KNB2 vs. electric fence" that started on August 3, 2008.
>
> 73
> --
> Joe KB8AP
>
>
> On Mar 1, 2009, at 2:18 PM, Brett Gazdzinski wrote:
>
>> I have tried it on various types of noises, some which sounded like
>> auto
>> ignition noise, I think someone had something running without
>> resistor wires
>> or plugs, strong and weak signals, no change.
>> I did have a bad street light out front of my house, the reason I
>> got the
>> NB, but they fixed it before I got the noise blanker.
>>
>> The main reason I asked was there seems to be no degradation of
>> signals with
>> the NB on at any setting.
>> On most rigs, you can hear a difference, and where its adjustable,
>> it makes
>> things sound really bad when you turn it up. The pro 3 is like that.
>>
>> On the K2, I have been unable to detect it doing anything at all,
>> any mode,
>> any noise, although the noise level I usually have is not bad.
>>
>> Thanks for the replies,
>> Brett
>> N2DTS
>>

Dick, K2ZR

Re: K2 noise blanker

Perhaps there's a comment from Elecraft on the K2's Noise Blanker
Dick, K2ZR/4

Brett Gazdzinski wrote:

>Joe,
>I will try this, thanks!
>
>Brett
>N2DTS
>
>----- Original Message -----
>From: "Joe Planisky" <[hidden email]>
>To: "Brett Gazdzinski" <[hidden email]>
>Cc: <[hidden email]>
>Sent: Sunday, March 01, 2009 6:03 PM
>Subject: Re: [Elecraft] K2 noise blanker
>
>
>
>
>>Hi Brett,
>>
>>Last summer, I had similar questions about the KNB2 in my K2. In my
>>case, a neighbor had put up a new electric fence and I was getting QRM
>>in the form of a pulse every second. The unmodified KNB2 seemed to
>>have little to no effect on the noise. In fact, I questioned whether
>>it was working at all. A 'scrape test' (connecting a wire to the
>>antenna connector and scraping it on some metal surface in the shack
>>to generate static) indicated that it was indeed working.
>>
>>The modification described here
>>
>>http://www.dl7maj.de/KNB2-Mod.pdf
>>
>>seemed to improve the situation. After making the mod described, the
>>KNB2 would partially take out the electric fence noise using the LEVEL
>>LOW threshold. Not perfect, but better than it was.
>>
>>You can read the original thread by searching the list archives for
>>the topic "[K2] KNB2 vs. electric fence" that started on August 3, 2008.
>>
>>73
>>--
>>Joe KB8AP
>>
>>
>>On Mar 1, 2009, at 2:18 PM, Brett Gazdzinski wrote:
>>
>>
>>
>>>I have tried it on various types of noises, some which sounded like
>>>auto
>>>ignition noise, I think someone had something running without
>>>resistor wires
>>>or plugs, strong and weak signals, no change.
>>>I did have a bad street light out front of my house, the reason I
>>>got the
>>>NB, but they fixed it before I got the noise blanker.
>>>
>>>The main reason I asked was there seems to be no degradation of
>>>signals with
>>>the NB on at any setting.
>>>On most rigs, you can hear a difference, and where its adjustable,
>>>it makes
>>>things sound really bad when you turn it up. The pro 3 is like that.
>>>
>>>On the K2, I have been unable to detect it doing anything at all,
>>>any mode,
>>>any noise, although the noise level I usually have is not bad.
>>>
>>>Thanks for the replies,
>>>Brett
>>>N2DTS
>>>
>>>
>>>
>______________________________________________________________
>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
>
>
>
>

AC7AC

Re: K2 noise blanker

In reply to this post by Brett Gazdzinski

CONTENTS DELETED

The author has deleted this message.

Brett Gazdzinski

Re: K2 noise blanker

In reply to this post by Joe Planisky

I did this mod last night.
I did not notice much if any difference.
I have to try the screwdriver on the transistor test Don told me about.

Since they fixed the streetlight, I don't have much noise, but have found
noise that sounds
very like ignition noise from a car, with no impact from the NB on it.

No big deal, since I don't have a lot of noise (now).

Brett
N2DTS

----- Original Message -----
From: "Joe Planisky" <[hidden email]>
To: "Brett Gazdzinski" <[hidden email]>
Cc: <[hidden email]>
Sent: Sunday, March 01, 2009 6:03 PM
Subject: Re: [Elecraft] K2 noise blanker

> Hi Brett,
>
> Last summer, I had similar questions about the KNB2 in my K2. In my
> case, a neighbor had put up a new electric fence and I was getting QRM in
> the form of a pulse every second. The unmodified KNB2 seemed to have
> little to no effect on the noise. In fact, I questioned whether it was
> working at all. A 'scrape test' (connecting a wire to the antenna
> connector and scraping it on some metal surface in the shack to generate
> static) indicated that it was indeed working.
>
> The modification described here
>
> http://www.dl7maj.de/KNB2-Mod.pdf
>
> seemed to improve the situation. After making the mod described, the
> KNB2 would partially take out the electric fence noise using the LEVEL
> LOW threshold. Not perfect, but better than it was.
>
> You can read the original thread by searching the list archives for the
> topic "[K2] KNB2 vs. electric fence" that started on August 3, 2008.
>
> 73
> --
> Joe KB8AP
>
>
> On Mar 1, 2009, at 2:18 PM, Brett Gazdzinski wrote:
>
>> I have tried it on various types of noises, some which sounded like auto
>> ignition noise, I think someone had something running without resistor
>> wires
>> or plugs, strong and weak signals, no change.
>> I did have a bad street light out front of my house, the reason I got
>> the
>> NB, but they fixed it before I got the noise blanker.
>>
>> The main reason I asked was there seems to be no degradation of signals
>> with
>> the NB on at any setting.
>> On most rigs, you can hear a difference, and where its adjustable, it
>> makes
>> things sound really bad when you turn it up. The pro 3 is like that.
>>
>> On the K2, I have been unable to detect it doing anything at all, any
>> mode,
>> any noise, although the noise level I usually have is not bad.
>>
>> Thanks for the replies,
>> Brett
>> N2DTS
>>

ka5oai

Re: K2 noise blanker

In reply to this post by AC7AC

Ron D'Eau Claire wrote

One of the early Elecraft customers, Sverre Holm, LA3ZA, put
together a wonderful page of K2 mods with links to the various documents.
Check here for info about the KNB2:

http://www.qslnet.de/member/la3za/K2/modAny.html#KNB2

on that page in the section about:
¤Increase time constants http://www.ac6rm.net/mailarchive/html/elecraft-list/2000-10/msg00086.html
or here http://www.ac6rm.net/mailarchive/html/elecraft-list/2000-08/msg00040.html are both 404 links

the gist of it said:
NB1: 10us ->70us
NB2: 70us->500us or 1ms
For electrical noise from motors, electrical fence etc
Increase C11 & C12
G3LUB
but I found no reference to values to change C11 &/or C12 to ???

after some digging I finally found the information here:
http://www.qsl.net/ve3mcf/elecraft_reflect/KNB2_Mods.txt

Date: Wed, 04 Oct 2000 16:04:31 -0600
From: Larry East <w1hue at ida.net>
Subject: [Elecraft] Noise Blanker Observations

Thought I'd add my two (binary) bits worth to the NB discussion:

I find that my NB is very effective on an annoying popping sound (mostly on
80M) that I suspect is caused by an electric fence in the area. NB1 reduces
it considerably and NB2 removes it completely. I get similar results for
certain types of static crashes: NB1 is somewhat effective and NB2 is very
effective. However, neither seems to be too effective against electrical
noise from drill motors, etc.

Back in August a couple of folks posted notes that they had increased C12
on the NB board by a factor of 10 to 20 (thus increasing the blanking gate
width to around 1-2 milliseconds) and got much better blanking of
electrical noise. So I decided to give that a try.

Increasing C12 to 0.1uF definitely resulted in better attenuation (with NB2
selected) of some types of electrical and atmospheric noise. However, it
resulted in a rather raspy sounding CW signals. Backing off to 0.047uF
worked just about as well on noise and did not produce any noticeable
effects on signals.

As a result, I have made the following mod to my NB board:

1. Changed C11 from 0.001uF to 0.0068uF (using the original C12 cap) to
give an NB1 blanking pulse width of 65-70 us (instead of 10 us).

2. Changed C12 from 0.0068uF to 0.047uF to give an NB2 blanking pulse width
of around 500 us (instead of 70 us).

Seems to be a good overall compromise for the types of noise that I hear.
Your results may vary.

72/73,
Larry W1HUE/7

the root page was this one:
http://www.qsl.net/ve3mcf/elecraft_reflect/index.html#k2modas

maybe the above info will save someone else some time searching for the info.

73 & GB
KA5OAI
Sam Morgan