Noise Blanker
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The results when using the Noise blanker has been mixed for me. I dont
have any luck with nearby electric fences. I always need to use the Low Threshold since the pulse levels are low. Sometimes it works sometimes it does not. I have the same mixed results on power line noise when the noise is aggressive and strong it works well. However it requires a specific level and type of noise to achieve the spectacular results some have demonstrated and reported. I am also disappointed that noise blanker does not work very well on rain static. Equally surprising is that the noise blanker works on some types of ignition noise and wont work on others. I would have thought that 2 stroke noise from motorbikes and farm machinery would have been a easy task for this noise blanker, not so. Again there is nothing wrong with my noise blanker. Every time i think its broke and i turn it off i am shocked at what i am hearing! So when it works it does work. I have compared it to several other radios. One radio in particular the TS830S has one of the most amazing all round noise blankers. All the noise the Elecraft noise blanker struggles on the TS830S noise blanker will handle on the low threshold setting. The same results can be had on my FT1000D, my mobile TS480 also handles the noise in a more able manner. The TS830S's noise blanker is a killer on rain static on a yagi, the K2's struggles to cope in comparison. My view is that the noise blanker needs a continuously variable threshold control, likewise a variable pulse width. Changing component values is just not a reality with noise appearing and disappearing. But i think we will have to wait for the K3, for fixes! Craig VK3HE _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Craig,
I have electrical fence impulse noise 24/7 unless the neighbors horse is out feeding on the lawn, then it is off. I find the DSP unit does what you like to see in your last par. You can customize it to work for various circumstances, but I am not the expert. Bill K9YEQ K2-35 & 5279; KX1-35/3080 ___________________________________ -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of ZD Sent: Tuesday, September 26, 2006 8:42 AM To: [hidden email] Subject: [Elecraft] Noise Blanker My view is that the noise blanker needs a continuously variable threshold control, likewise a variable pulse width. Changing component values is just not a reality with noise appearing and disappearing. But i think we will have to wait for the K3, for fixes! Craig VK3HE _______________________________________________ _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Zd-2-3
VK3HE commented:
>I have compared it to several other radios. One radio in particular the >TS830S has one of the most amazing all round noise blankers. All the >noise the Elecraft noise blanker struggles on the TS830S noise blanker >will handle on the low threshold setting. The same results can be had on >my FT1000D, my mobile TS480 also handles the noise in a more able >manner. The TS830S's noise blanker is a killer on rain static on a yagi, >the K2's struggles to cope in comparison. Careful, it is not valid to compare the functionality of the NB against other radios. NBs do not work on some noises & all cause the receiver to wilt from IMDs. Or so we hear each time somebody wonders why the K2 NB doesn't seem to do anything. Strange, I also find other radios' NBs to work fine on a wide range of noises & will do so without adding much of anything untoward. None of them require scratching a transistor case with a screwdriver to establish that the NB works - just flick the front panel switch will suffice. They can take a bite out of some atmospherics & even stuff like power line noise & the British or Chinese woodpeckers - not completely, but often enough to be able to hear what I need to hear through it. But not on the K2. The K2's NB either does nothing or makes things worse - exactly what we are told here is what all NBs do. My other radios do not have AGC image responses, nor are they so inconsistent with amount of AGC response for a constant level signal on the various bands. My other radios may have NB threshold knobs, but I rarely have to touch them. Turn on NB, noise is reduced or goes away, without introducing anything untoward. IMHO, much of the problem with the K2's NB has to do with this variability in gain across the band, between bands & the additional variable of AGC image response. The efforts to explain it away will not change the fact that the K2's NB is the worst performing NB of any radio I have ever used. That the subject keeps coming up here does suggest there might be room for improvement, but again this is based on the invalid comparison with other radios, so we had best shut up, mate. 73, VR2BrettGraham _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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It is designed to filter out man-made noise like from cars,
electrical devices in your home, malfunction street lights, etc. I would not count on them to "remove" anything else. Ron, wb1hga VR2BrettGraham wrote: > NBs do not work on some noises & all cause the > receiver to wilt from IMDs. > They can take a bite out of some atmospherics & > even stuff like power line noise & the British or > Chinese woodpeckers - not completely, but often > enough to be able to hear what I need to hear > through it. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by VR2BrettGraham
VR2BrettGraham wrote:
> Strange, I also find other radios' NBs to work fine > on a wide range of noises & will do so without > adding much of anything untoward. All noise blankers that I've used cause some degradation of the receiver's dynamic range performance. This means that in a strong signal environment (like in a contest) you will hear spurious responses when it is on. This is of course a matter of degree, and I know there are sophisticated circuits that are much better than others in this respect. > They can take a bite out of some atmospherics I have *never* used or even heard of a noise blanker that reduces atmospheric noise (by which I mean that generated by thunderstorms)! Yes, an antenna noise canceller can do this, but we're talking about noise blankers. > The efforts to explain it away will not change the fact > that the K2's NB is the worst performing NB of any > radio I have ever used. Then you must not have used the unmodified TS850s noise blanker! > That the subject keeps coming up here does suggest > there might be room for improvement, but again this > is based on the invalid comparison with other radios, > so we had best shut up, mate. I don't disagree that the K2 noise blanker could be much, much better. But an improved one would be much more complicated. It would probably need to me built with SMT components to fit in the available space. I think -- given the noisy environments that most of us live in, and the fact that this will only get worse -- that noise reduction should be one of the primary receiver design considerations. Because of the difficulty involved in doing it without compromising dynamic range too much, the noise blanker should be designed as part of the basic receiver, from the start, and not as an add-on (although the module itself could be optional). My dream receiver would have an adaptive, computer-assisted noise reduction system that would combine early noise blanking with DSP and possibly other techniques. BPL is just one of many of the new kinds of noise we are facing. -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: Noise Blanker
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In reply to this post by Zd-2-3
Vic, K2VCO wrote:
>All noise blankers that I've used cause some degradation of the receiver's >dynamic range performance. This means that in a strong signal environment >(like in a contest) you will hear spurious responses when it is on. This is >of course a matter of degree, and I know there are sophisticated circuits >that are much better than others in this respect. --------------------------------------------------------- Hi Vic, And some types do not degrade the receiver's dynamic range at all, nor introduce spurious responses in a strong signal environment. The bottom line is cost, not too much if homebrewing. 73, Geoff GM4ESD _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Zd-2-3
Hello all;
I push on a CW "filter" and it does the same thing! I also press attenuate with same results! Unh? Noise blanker and/or filter does same thing? Why? Because filters and NB may "appear" to remove atmospheric noise, but it's still there, because it's attenuated. (There's a little more to that but not here) Noise blankers work more effectively on man-made noise such as automobiles, lights, motors, hair dryers (pulse type noise) etc. Not atmospheric noises. Oh, after you did that, you probably had to turn up the volume a bit like I did. It make for easier listening though. Regardless, I love me K1. (smile) Ron, wb1hga W.D. (Doc) Lindsey wrote: > evening here on 30Metres, and the QRN seemed incessant, I [probably] > accidentally pushed the NB button on a K2. And suddenly the noise all but > disappeared. Since then I have come to use it regularly, as there seems to > be a whole lot of QRN here in the tiny subdivision. But the NB will > normally knock it down to listenable levels. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Zd-2-3
In my K2 # 5422 - I built two (2) NB kits, with no
luck in either doing much with "noise". For sure it did nothing on ignition/truck noise (3 cement trucks outside our doors). And it did nothing to reduce or change what I call repetitive popcorn white noise signals on bands. Hooked up to a wet noodle wire antenna - I could never verify any operation of NB at all. Someone suggested it only works in high signal level noise situations. Perhaps ....... K3NB? Fred FL __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Ignition noise from large trucks??? All of the ones I've seen are diesel -
no spark ignition at all! Such trucks often make a lot of hash from various electric motors, etc. - just the sort of thing the NB can't touch. Did you remove jumper W5 from the K2's RF board when you installed the NB? Ron AC7AC -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Fred (FL) Sent: Sunday, October 01, 2006 2:28 PM To: [hidden email] Subject: Re: [Elecraft] Noise Blanker In my K2 # 5422 - I built two (2) NB kits, with no luck in either doing much with "noise". For sure it did nothing on ignition/truck noise (3 cement trucks outside our doors). And it did nothing to reduce or change what I call repetitive popcorn white noise signals on bands. Hooked up to a wet noodle wire antenna - I could never verify any operation of NB at all. Someone suggested it only works in high signal level noise situations. Perhaps ....... K3NB? Fred FL _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Zd-2-3
In a message dated 10/1/06 6:58:53 PM Eastern Daylight Time,
[hidden email] writes: > Ignition noise from large trucks??? All of the ones I've seen are diesel - > no spark ignition at all! > Many of not most auto and truck diesel engines made in recent years use electronic injection control. Instead of the familiar distribution-type injection pump with individual fuel lines to the injectors, there's a single high pressure fuel rail feeding all the injectors. The injectors are electronically controlled - which can be a source of RFI. There's also a ton of other electronics on most modern vehicles, too. 73 de Jim, N2EY _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Yep, that's why I also wrote in the message you quoted from:
"Such trucks often make a lot of hash from various electric motors, etc. - just the sort of thing the NB can't touch. " My NB works FB, but is by far does the most spectacular job on high-amplitude short-duration pulses like ignition noise and cheap lamp dimmers. That QRN just disappears when the NB is turned on even though it may be blanketing all signals without the NB. Most other QRN sources helped very little or not at all by the NB in my experience. That would include most of the QRN coming from non-ignition sources in large vehicles. Have you had success in dealing with those sorts of QRN using the NB, Jim? I know there're some mods folks have made to the NB but I haven't tried them. Other that cheap lamp dimmers that appear from time to time, I live in a very quiet QTH, fortunately! Ron AC7AC -----Original Message----- In a message dated 10/1/06 6:58:53 PM Eastern Daylight Time, [hidden email] writes: Ignition noise from large trucks??? All of the ones I've seen are diesel - no spark ignition at all! Many of not most auto and truck diesel engines made in recent years use electronic injection control. Instead of the familiar distribution-type injection pump with individual fuel lines to the injectors, there's a single high pressure fuel rail feeding all the injectors. The injectors are electronically controlled - which can be a source of RFI. There's also a ton of other electronics on most modern vehicles, too. 73 de Jim, N2EY _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Zd-2-3
In a message dated 10/2/06 10:45:35 AM Eastern Daylight Time,
[hidden email] writes: > Yep, that's why I also wrote in the message you quoted from: > > "Such trucks often make a lot of hash from various electric motors, etc. - > just the sort of thing the NB can't touch. " Agreed! My only real point was that the electronic injectors can make noise similar to an ignition system. OTOH, a diesel like this one: http://people.bath.ac.uk/ccsshb/12cyl/ > > My NB works FB, but is by far does the most spectacular job on > high-amplitude short-duration pulses like ignition noise and cheap lamp > dimmers. That QRN just disappears when the NB is turned on even though it > may be blanketing all signals without the NB. > > Most other QRN sources helped very little or not at all by the NB in my > experience. That would include most of the QRN coming from non-ignition > sources in large vehicles. > > Have you had success in dealing with those sorts of QRN using the NB, Jim? > I know there're some mods folks have made to the NB but I haven't tried > them. Other that cheap lamp dimmers that appear from time to time, I live in > a very quiet QTH, fortunately! In my limited experience, the only type of noise that blankers and limiters help is exactly the type you describe - high-amplitude, short-duration pulses. Other types of noise, by their very nature, cannot be helped by a blanker or limiter. I think there's a lot of confusion on the subject of "noise", because the word lumps together all sorts of QRN with very different characteristics. 73 de Jim, N2EY also pretty lucky in the QTH _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Jim wrote:
My only real point was that the electronic injectors can make noise similar to an ignition system. OTOH, a diesel like this one: http://people.bath.ac.uk/ccsshb/12cyl/ ------------------------------ I didn't realize that. Thanks! Wow! That's an ENGINE! It reminds me of the time I stopped in to deliver some parts of a marine warehouse. I had been into the engine room of enough modern ships to no longer be impressed by engines bigger than my house, but this time I was surprised. It was lunch hour and, looking for the guys to give the package to, I found them having lunch deep in the huge building. They were sitting about six feet or so up on a huge round platform of some sort, munching away on sandwiches with their lunchboxes open. After I got the signatures I took a look at what they were sitting on. It was a piston from a marine engine, just like what you'd expect in an automobile but about six feet high and nearly as big around. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Man
The extremes these guys go through to deliver that package! (heh heh) Ron wb1hga Ron D'Eau Claire wrote: > It was lunch hour and, looking for the guys to give the package to, I found > them having lunch deep in the huge building. They were sitting about six > feet or so up on a huge round platform of some sort, munching away on > sandwiches with their lunchboxes open. After I got the signatures I took a > look at what they were sitting on. It was a piston from a marine engine, > just like what you'd expect in an automobile but about six feet high and > nearly as big around. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by roncasa
I'm arriving at this conversation a bit late, but let me ask this question.
I have a relatively newly assembled K-2, working perfectly as far as I can tell. I have the KNB2 assembled and ready to install. After reading these posts, I'm wondering if I should bother to do it. I find, as Ron said, the filters do a good job with atmospheric noise. I don't have anything else unusual here in the way of noise. Sometimes I get line noise, but it's so irritating I usually don't try to work through it. I'll wait it out. So, should I risk the uninstalling of resistors and cutting of jumpers on a good radio for the improvement offered by the noise blanker? Jimmy Walker WA4ILO Macon, GA ----- Original Message ----- From: "ron" <[hidden email]> To: <[hidden email]> Sent: Wednesday, September 27, 2006 5:50 PM Subject: Re: [Elecraft] Noise Blanker > Hello all; > > I push on a CW "filter" and it does the same thing! > I also press attenuate with same results! > > Unh? Noise blanker and/or filter does same thing? > > Why? > Because filters and NB may "appear" to remove atmospheric noise, but it's > still there, because it's attenuated. (There's a little more to that but > not here) > > Noise blankers work more effectively on man-made noise such as > automobiles, lights, motors, hair dryers (pulse type noise) etc. > Not atmospheric noises. > > Oh, > after you did that, you probably had to turn up the volume a bit like I > did. > It make for easier listening though. > > Regardless, I love me K1. > (smile) > > Ron, wb1hga > > W.D. (Doc) Lindsey wrote: > > >> evening here on 30Metres, and the QRN seemed incessant, I [probably] >> accidentally pushed the NB button on a K2. And suddenly the noise all >> but >> disappeared. Since then I have come to use it regularly, as there seems >> to >> be a whole lot of QRN here in the tiny subdivision. But the NB will >> normally knock it down to listenable levels. > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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NB removes man-made noise, NOT atmospheric noise.
Filters DO NOT remove man made noise. Nor do they remove atmospheric noise. As I wrote, they give the appearance the noise is gone, when turned on to narrow the bandwith. That's why you turn up the volume a bit to compensate. The filter's job is to reduce bandwith. (there's more but not here) There is no "risk" to install NB's and it's a positive move. It just may rid of that line noise you wrote. You will enjoy your radio more, instead of waiting for that to go away. (smile) Ron, wb1hga Jimmy Walker wrote: I find, as Ron said, the filters do a good job with atmospheric noise. I don't > have anything else unusual here in the way of noise. Sometimes I get > line noise, but it's so irritating I usually don't try to work through > it. I'll wait it out. > > So, should I risk the uninstalling of resistors and cutting of jumpers > on a good radio for the improvement offered by the noise blanker? _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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I is my experience that the K2 Noise Blanker is quite effective on certain types of impulse noise, while of little help on others, i.e., it is quite dependent on the characteristics of the noise. For atmospheric noise, the noise reduction function of the KDSP2 works better than anything else I have tried. I recommend having both. 73 - Bob, N7XY _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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