I'm still looking for the above, either kit or assembled. My lead fell
through.
Please contact me off list at w3ab at w3ab.org.
Thank you.
---
73 de W3AB/GEO
AFA9GB
WA2LSI, KE6RJW, W7B, AAR9AG
__
Elecraft mailing list
Home:
I just recently built the KNB2 and it does not seem to be very effective for
the noise pulses near my house.
I also put a the KNB1 in my K1 with disappointing results.
I'm comparing this to my K3 and KX3 that almost completely eliminate the
noise.
Doing some internet research there appears to be
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Stan AE7UT
Sent: Wednesday, October 09, 2013 2:07 PM
To: elecraft@mailman.qth.net
Subject: [Elecraft] KNB2 - looking for experience with mods that made it
effective
I just recently built the KNB2 and it does not seem to be very effective for
the noise
Stan,
First check the KNB2 to be certain it is working. With no antenna on
the K2 and the preamp on, tap a metallic object (screwdriver) against
the case of Q21 - you should hear clicks (ignore the 'rushing' sound of
the screwdriver acting as an antenna). Turn on the NB and the clicks
Thanks Don and Ron.
I checked the NB and it appears to be working fine.
I added the .001 and didn't notice any significant change in the pulsing
noise I'm hearing.
I wish I could show a screen shot from my P3. There are multiple large
swaths of pulsing
S9+ RF in this rural town. I do live
Stan,
As I indicated, slow rise time noises (like powerline noise) will not be
squelched by the KNB2 nor the KNB1. They will work on fast rise time
noise pulses like from auto ignition noise or lightning, but will not
work on continuous noise sources like powerline noise.
The KX3 (and the
Or electric fence noise. Fence chargers pulse a couple of KV at roughly
1 per second give or take a half-second. When weeds grow up under the
wire [they ALWAYS do :-)], the arc from the wire to the weed is a very
short, fast rise-time pulse.
I have an electric fence. The weeds grow for me
Sounds like Plasma TVs I have one local that pretty messes up
stuff around 3820 and it drifts ,,, put together a small loop and try to
DF it
Bob K3DJC
On Wed, 9 Oct 2013 16:20:43 -0700 (PDT) Stan AE7UT ae7...@gmail.com
writes:
Thanks Don and Ron.
I checked the NB and it appears to be
Just a few observations regarding NR and NB, from an op at a QTH that is
at times plagued by powerline noise:
Since the KDSP2 provides Noise Reduction (NR) as opposed to Noise Blanking
(NB), the best that it can do with *any* noise is to make it easier on the
ears. It will not however drop the
I built the KNB2 board and installed it today.
No problems with that, but it occurred to me while the 100 Watt board
was removed to check the TO220 packaged Q7 and Q8 on the RF board for
any electrical continuity to the heat sink .
I have to back those 4-40 nuts out to barely finger tight or it
Larry,
You probably have some slivers of aluminum embedded in the thermal pads.
Unless you have some good thermal conductive material laying around, I
would request replacement thermal pads from pa...@elecraft.com.
BTW - when you replace the hardware, do not use the internal toothed
Don, thanks.
Larry
K5END
On Sun, 2011-01-23 at 20:50 -0500, Don Wilhelm wrote:
Larry,
You probably have some slivers of aluminum embedded in the thermal pads.
Unless you have some good thermal conductive material laying around, I
would request replacement thermal pads from
Hello Elecrafters,
In the archives there are several messages regarding the effectiveness or
lack of effectiveness of the KNB2 noise blanker for the K2. Having just
finished assembly of one for my recently completed K2 I wanted to share my
findings.
This kit is an easy build with only
Hi everybody;
My next door neighbor just purchased a new 40+ flat screen TV. When He
turned it on, my little K2 just about jumped off the operating table!
The EMI is pretty bad. After thinking about a non violent cure for a while I
discovered a little mod to my KNB2 that turned out to really
Joe Planisky wrote:
Hey folks,
I've recently started picking up relatively strong pulses at 1 second
intervals on my K2. I suspect they're coming from a new electric
fence somewhere in the neighborhood. But where they're coming from is
immaterial to my question.
Should the
Good Day to all,
I have had prior problems with my neighbors electric fence used to contain
his horses. I don't have much experience with the NB in the K2. i am using
the K3 which does a wonderful job. I guess the first thing I would do is
make sure the interference you are hearing is in fact
PROTECTED]
Sent: Monday, December 24, 2007 11:18 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] KNB2 diagnosis
Chris,
I installed a KNB2 in my K2 a few months ago. I didn't think it worked until
I tried the scratching of Q21 as recommended.
With the top off and background noise coming from
-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Stan Rife
Sent: Wednesday, December 26, 2007 4:19 PM
To: elecraft@mailman.qth.net
Subject: RE: [Elecraft] KNB2 diagnosis
I'll admit that I am pretty gullible, until I prove otherwise, but
scratching the top of a transistor
Stan,
Scratching Q21 is certainly NOT a *fix* by any means!!! It is a 'GO --
NO-GO' test only.
BUT it is one 'no-tools' method that can effectively produce the noise
that the KNB2 is capable of suppressing. Of course, the preamp must be
on to bring Q21 into the circuit.
73,
Don W3FPR
- Original Message -
From: Stan Rife [EMAIL PROTECTED]
To: elecraft@mailman.qth.net
Sent: Wednesday, December 26, 2007 7:18 PM
Subject: RE: [Elecraft] KNB2 diagnosis
I'll admit that I am pretty gullible, until I prove otherwise, but
scratching the top of a transistor as a fix Ha ha ha
K6DBG wrote
Some of the time, my pulses just die at the output of R8, which goes to ground
via L1. I'm not sure exactly what I do differently when the pulse gets past -
perhaps just how hard I'm tapping?
Sounds strange, if you hear the noises coming through your K2 (with the NB
off), they
I've never been convinced that my KNB2 worked as planned. I have the K2 open
today to install the K160RX, and decided to work on the KNB2.
I found the archive messages about scratching Q21. I can only get any noise
out of this with the pre-amp on - don't know if that's as expected or not. No
Chris,
I installed a KNB2 in my K2 a few months ago. I didn't think it worked until I
tried the scratching of Q21 as recommended.
With the top off and background noise coming from the speaker, I toggled from
NB1 to NB2 to OFF while I scratched the case of Q21. It worked. I saw a
definite
Hi,
The Noise Blanker I built wasn´t working but now we found out that a bad
transistor(Q6) caused the problem.We replaced it and my K2 works fine.I thought
I should let you know, maybe this information is useful for someone.
73, Chris-OE5CSP
--
Ist Ihr Browser Vista-kompatibel? Jetzt die
Ok I have gone over my KNB2 Board twice now to see why
it will not blank any noise. I had a friend of mine
come over here with his and we used my noise source.
(1948 Ferguson Tractor) Noisy ignition. He set his for
nb1 and badda bing badda boom all gone mine still
there. NB2 Still there. I asked
David,
To test, turn on the preamp and tap Q21 with a screwdriver tip - you can
tell when the sharp 'clicking' with each tap is taken out by the KNB2.
There is not a lot of circuitry on the KNB2, so I suggest that you check
all the components for correct values, and in the right positions.
I'm offering this just on the off-chance you haven't tried it.
Sometimes the noise level that roars out of the speaker with the AF gain
turned up really isn't strong enough to trigger the NB even at low threshold
levels. In that case, turning the Preamp On (and turning the audio gain
down) often
I Gang
I bought the KNB2 noise blanker last week for my K2 so
I can go mobile. My truck has a little bit of ignition
noise from time to time. Well I Got it built installed
it
put in the truck and well I don't see any difference.
I drug out my ft 100d which is going to have to go
back to the
Hi to all on list,
Last weekend I went to a nice QTH out in the country, which belongs to a
friend, for the RSGB 80M AFS CW contest, here in the UK.
I had intended to use my K2 in the contest but S9+20db QRN from a
neighbouring farmer's electric fence put and end to that hope. Using the
KNB2's
Allan,
C11 controls the width of the NB1 gate and C12 changes the width of the NB2
gate. You may want to experiment with the values to find what will work
with your particular noise. I can't say if you will find any improvement.
The best help would be to ask permission from your neighbor to
Allan Duncan wrote:
I see that on the LA3ZA modification pages there are some capacitor changes
that change the time constants in the KNB2. Unfortunately the links to the
mods themselves seem to be broken.
My questions to the list are, will changing C11 and C12 (value unknown)
likely to help
I see that on the LA3ZA modification pages there are some capacitor
changes
that change the time constants in the KNB2. Unfortunately the links to the
mods themselves seem to be broken.
These links are to www.qsl.net which seems to be down for the moment. I try
to avoid links to qsl net on the
I have a local noise that I can't get the NB in my K-2 to knock out.
http://tinyurl.com/reqdp
The NB on my IC-735 does so I'm hoping I can tweak my K-2 NB to
eliminate it. I tried the C-11 to .0068uF and C-12 to .047uF change
per the Mods site and no real improvement. Any other ideas would be
My experience with the KNB2 is completely negative. I even built a
second one, tweaked etc. It does not even compare to ICOM or Yaesu
NB's. Wayne, time to redesign. No more spin on what it was designed
to do. No matter what it was designed to do, it doesn't eliminate or
reduce the most typical
I built, tested and installed KNB2 Noise Blanker,
in my K2 # 5422 - on 6 May 2006.
Still in the SWL mode, awaiting a stealth antenna, and
having gotten my K2 # 5422 aligned and KSB2 installed
- I've only practiced with using this
KNB2 Noise Blanker on noisy band (CW and SSB)
conditions.
The
On my K2's NB (KNB2, May 2006) - It seems no matter
what type of random, or periodic band noise is present
- activating the KNB2 doesn't affect the noise
in any fashion? It doesn't get louder, or quieter,
or no noise goes away, and noise doesn't get any
better.
So I guess, besides the OK
Hello all,
I'm sorry, but again the KNB2.
I wrote some mails a few months ago about the effectiveness of the KNB2 in
my specific situation. I was not happy with the performance as delivered
from factory.
So I changed the capacitors C11 and C12 as proposed by Larry W1HUE/7.
Unfortunately I
I have sharp pulses on all bands hitting the band about once per second,
which the noiseblanker of my old IC 735 kills, but not so my K2 S/N 4765.
I can - more or less - read a circuit diagramm (I don´t understand each
components function in detail yet) I´ve tried some signal tracing,
couldn´t
Karsten,
Sounds like the noise is outside of the KNB2's range. There is a mod for wider
spaced noise like you describe. See
http://www.qslnet.de/member/la3za/K2/modAny.html#KNB2
What you describe sounds like an electric fence.
There was some discusion about an improved noise blanker on the
Hi Karsten,
I have found the same thing. I have bad power line noise.
Sometime the K2 NB takes it all out, sometimes not.
My IC-735 takes all the noise out.
I get the KNB2 to work sometimes by putting the pre-amp
ON, then try both high and low thresholds, and both timings.
73 de K3YT
Thank you Darrell,
I checked the pulse width, and in fact it is 500 usec or broader, while
the KNB2 spec is 10 to 70 usec.
Seems I have to play with C11 and C12.
Still, if could get hold of a diagram, that shows what to measure
where, it would be appriciated.
73
Karsten
DK4AS
Darrell
This circuit may help you evaluate your KNB2.
http://www.electronics.50g.com/cpg.htm
I used 1.8 megohm fixed for the base resistance. With 5V input, output
is about 4V.
Varying C1 from 470pf thru .047uf varies the pulse width from approx. 10
uS to 500 uS.
73TedAA5CK
I just finished wiring and installing a KNB2 in my K2. When I turn the rig
on, I get the Elecraft display, then it goes to the normal frequency
display. When I press the NB button, I get the same not inst
message that I got before I installed this module.
Following the troubleshooting hints in
Of Allan Bacon
Sent: Sunday, November 27, 2005 6:34 PM
To: elecraft@mailman.qth.net
Subject: [Elecraft] KNB2 not installed
I just finished wiring and installing a KNB2 in my K2. When I
turn the rig
on, I get the Elecraft display, then it goes to the normal frequency
display. When I press
I've had my K2 built for about 2 months now. Everything works except the noise
blanker. I've looked at a lot of archives on this. What I have done to test
it is:
1. Scratch the top of Q21 on the RF board to generate noise.
2. Using an oscilloscope, I can trace the noise pulse through Q2-Q4
on the
collector.
Good hunting.
Gregg R. Lengling, W9DHI, Un-Retired
K2/100 SN 3075
http://www.milwaukeehdtv.org
- Original Message -
From: [EMAIL PROTECTED]
To: elecraft@mailman.qth.net
Sent: Tuesday, November 15, 2005 8:36 AM
Subject: [Elecraft] KNB2 Noise Blanker Not Working
I've
Hi all!
I´ve just finished installation of the KNB2 into my K2. When tapping
the NB-button on the K2, the display shows Not Inst. I have
re-examined the KNB2 board. U3 is installed/soldered correctly and as
far as I can see no other components are installed incorrectly or
backwards. I have also
Hans,
The Not Inst message means only one thing - the KNB2 is not communicating
with the K2 MCU. That comunication occurs over the Auxbus line. That
signal is present at pin 7 of the KNB2 connector.
I suggest that you check for continuity (and shorts) from the K2 Control
board MCU pin 40 to
Following my previous post about the effectiveness of the noise blanker in the
presence of severe electrical interference I changed the value of C12 to 0.47.
In all cases except one particular train configuration I can now operate. The
small holes being made in the received signal turn ssb
LA1PHA K2/100 3829 , K1 1491
- Original Message -
From: Darrell Bellerive [EMAIL PROTECTED]
To: elecraft@mailman.qth.net
Sent: Monday, July 18, 2005 7:06 AM
Subject: Re: [Elecraft] KNB2 Performance
Perhaps one of the design wizards that reads this list could come up with
something like
gladly throw an extra $30,40,50 for a high performance NB.
Tom LA1PHA K2/100 3829 , K1 1491
- Original Message -
From: Darrell Bellerive [EMAIL PROTECTED]
To: elecraft@mailman.qth.net
Sent: Monday, July 18, 2005 7:06 AM
Subject: Re: [Elecraft] KNB2 Performance
Perhaps one
Unfortunately, the KDSP2 is in the wrong part of the receiver chain for
impulse noise reduction. Effective impulse noise reduction needs to be done
at the RF/IF level before filtering. The crystal filter in the IF will
distort and elongate the noise pulse making it much more difficult to
blankers in the process.
So, what's with the KNB2? Possibly one reason the Elecraft KNB2 fails
this test is because it was designed after the LORAN A stations and the
Woodpecker were history. I don't know this for a fact, it is just
supposition. However, I maintain that a good noise blanker
with different specs available.
Evert, PA2KW
K2, #4836
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Joe Squarzini
Sent: 17 July 2005 18:30
To: elecraft@mailman.qth.net
Subject: [Elecraft] KNB2 Performance
I too have found the KNB2 lacking in most real world noise
Perhaps one of the design wizards that reads this list could come up with
something like this http://www.ussc.com/~turner/syn_blank.html adapted for HF
and the K2.
My guess is that noise blanker effectiveness is directly related to the
characteristics of the noise. One blanker's design specs
-Original Message-
The problem with checking most noise blanker is generating the necessary
test conditions to see if the operation is correct. Most radio equipment
manufacturers are rather vague in this respect and I have yet to find a
piece of test equipment that will provide
At 04:24 AM 1/2/2005, Stewart Baker wrote:
On Sat, 1 Jan 2005 17:51:33 -0800, wayne burdick wrote:
And now a word from the designer ;)
--
I'm not sure when we'll be able to update the KNB2 design, but in the
meantime, I'll be happy to answer questions for anyone who wants to try
their
G'day,
1.Both birdies in #1400 are at the LF band edge of 10M one is from the
K2 MCU clock the other is from the KPA100 processor clock. The latter can
be put where you wish depending upon your priorities, no birdie at the top
end of 75M or no birdie at the bottom end of 10M, take your
In general less than stellar performance of the KNB2 circuit in some cases
depends on the type of pulse noise that someone tries to eliminate and not to
dysfunction of the board itself.
It is true that the KNB2 tends to be picky on the type of noise that it is
most effective against, but for
Message -
From: Vic Rosenthal [EMAIL PROTECTED]
To: David Zatopek KT5V [EMAIL PROTECTED]
Cc: elecraft@mailman.qth.net
Sent: Tuesday, November 09, 2004 12:47 AM
Subject: Re: [Elecraft] KNB2 - odd behavior
David Zatopek KT5V wrote:
During SS this past weekend, I QSYed to a well-load 40 late
If I am monitoring the CW portion of the 40 meter band and have my NB
switched on, I can always tell when someone aboard the USS Requin decides to
do some QRP ops. I live atop Mt.Washington in Pittsburgh, PA, while the
submarine is docked immediately below in the Ohio river at the Carnegie
Hi, Vic, thanks for the reply. I was fairly certainly that the crowd of
large signals had something to do with this, but had never observed this
before. Probably because my other HF rig's blanker doesn't really blank
The K2 blanker has become indispensable in my semi-urban environment.
73 de
During SS this past weekend, I QSYed to a well-load 40 late Sunday and
noticed an impressive and unusual level of S9 noise. The NB1 was on at the
time of the QSY (HI THRU). The DSP denoiser and a tighting of filters
helped, but the noise was pervasive and still S5. On whim, I turned off the
David Zatopek KT5V wrote:
During SS this past weekend, I QSYed to a well-load 40 late Sunday and
noticed an impressive and unusual level of S9 noise. The NB1 was on at the
time of the QSY (HI THRU). The DSP denoiser and a tighting of filters
helped, but the noise was pervasive and still S5.
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