K3 Noise Blanker ahead or behind roofing filter?
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K3 Noise Blanker ahead or behind roofing filter?
 
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I have K2 SN 1031 and an IC-746PRO. Last week my next door neighbor
brought home a large screen TV that looks to be the rear projection type. I didn't pay much attention to it as they unloaded it but now find it puts out lots of QRN. It puts out S9 on the PRO 60 HZ QRN on 20, 15, 10 6 and 2 meters. Those are the bands I have antennas that work. The noise blanker in theK2 and the PRO both eliminate this bad QRN right down to the background noise :-) when there are now strong signals on the band but when a strong station such as the W1AW code sessions come on 20 meters, (20 over 9 in ND), than the K2 using NB1 has problems 5 KHZ or so either side of W1AW. NB2 has problems up to 10 KHZ either side of W1AW and the PRO has problems 15 KHZ either side of W1AW :-( . Is the noise blanker on the K3 ahead of the roofing filter or behind the roofing filter. If it is behind the roofing filter buying a K3 might put me back on the air :-) but if it is ahead of the roofing filter than would I have the same problem as the K2 :-( ? I have looked at the FAQ part of the Elecraft K3 site and do not find the answer to this question. I just need a short answer so please do not start a long thread on my station or observations etc. 73 and thanks for the help. W0CZ _______________________________________________ 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: K3 Noise Blanker ahead or behind roofing filter?
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I would ask the people if I could put a filter on the power line to the TV. That might reduce or eliminate the QRN. Maybe get a surge protector/filter setup and convince them it's a protection device for their investment. I bought phone filters and installed them on the neighbors on both sides of my house to eliminate the AM getting in the phones. I also had to filter an audio system with extended speaker wires as I came through quite loud even with the thing turned off. Some caps across the speaker outputs cured it totally! Brett N2DTS > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of > Kenneth A. Christiansen > Sent: Tuesday, June 12, 2007 7:50 AM > To: [hidden email] > Subject: [Elecraft] K3 Noise Blanker ahead or behind roofing filter? > > I have K2 SN 1031 and an IC-746PRO. Last week my next door neighbor > brought home a large screen TV that looks to be the rear projection > type. I didn't pay much attention to it as they unloaded it > but now find > it puts out lots of QRN. It puts out S9 on the PRO 60 HZ QRN > on 20, 15, > 10 6 and 2 meters. Those are the bands I have antennas that work. The > noise blanker in theK2 and the PRO both eliminate this bad QRN right > down to the background noise :-) when there are now strong > signals on > the band but when a strong station such as the W1AW code > sessions come > on 20 meters, (20 over 9 in ND), than the K2 using NB1 has problems 5 > KHZ or so either side of W1AW. NB2 has problems up to 10 KHZ > either side > of W1AW and the PRO has problems 15 KHZ either side of W1AW > :-( . Is the > noise blanker on the K3 ahead of the roofing filter or behind the > roofing filter. If it is behind the roofing filter buying a > K3 might put > me back on the air :-) but if it is ahead of the roofing filter > than would I have the same problem as the K2 :-( ? I have > looked at the > FAQ part of the Elecraft K3 site and do not find the answer to this > question. I just need a short answer so please do not start a long > thread on my station or observations etc. > > 73 and thanks for the help. > > W0CZ > _______________________________________________ > 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 |
Re: K3 Noise Blanker ahead or behind roofing filter?
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Hello Brett,
Sorry, this is a little off topic, but ... Shunting loudspeaker terminals on an amplifier (or at the loudspeakers themselves) may cause instabilities with some amplifiers due to phase shift, causing them to break into oscillation well out of hearing range, resulting in possible failure of the output transistors (at the very least), and some embarrassment and expense to the applicator :-) It's usually more effective (and will not cause any instabilities to the amplifier) to place ferrite beads over the individual wires or over the pair of wires (whichever works best) as near to the loudspeaker terminals on the amplifier/receiver as possible. Sometimes, due to the size of the connector terminals at the ends of the wires, it is not possible or practical to fit a ferrite bead over the wire. In those instances, you can obtain some split cores from Radio Shack, Mouser, Digi-Key, etc. that will allow you to wrap several turns of wire around half of the ferrite core that is temporarily opened, after which you can close it again. Keep adding more of these devices until you no longer have a problem. 73, Dale WA8SRA Brett gazdzinski wrote: > .... Some caps across the speaker outputs cured it > totally! > > Brett > N2DTS > > _______________________________________________ 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: K3 Noise Blanker ahead or behind roofing filter?
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In reply to this post by Brett gazdzinski-2
Most RF-spectrum noise generated by TV sets and computers and radiated by the
power line is common-mode noise, and the typical differential-mode (in-line) power filter will do nothing to suppress it. You need to make a common-mode RF choke. Get some large ferrite toroid cores (Palomar Engineers as well as others sell them) and wind the entire power cord of the TV through a couple of these in series. (In less severe cases, just one toroid may do the trick.) The toroid needs to go as close to the TV set as possible, as any unshielded conductor between the toroid and the power supply will still radiate. You can also encase the whole power cord in clamshell ferrites if you can find them in the correct size, but I've found this to be less effective than toroids. The benefit of this method is that you don't have to supply an extension cord to replace the length of the power cord you wound through the toroids. Bill / W5WVO Brett gazdzinski wrote: > I would ask the people if I could put a filter on the power > line to the TV. > > That might reduce or eliminate the QRN. > > Maybe get a surge protector/filter setup and convince them > it's a protection device for their investment. > > I bought phone filters and installed them on the neighbors on both > sides of my house to eliminate the AM getting in the phones. > I also had to filter an audio system with extended speaker > wires as I came through quite loud even with the thing > turned off. Some caps across the speaker outputs cured it > totally! > > Brett > N2DTS > >> -----Original Message----- >> From: [hidden email] >> [mailto:[hidden email]] On Behalf Of >> Kenneth A. Christiansen >> Sent: Tuesday, June 12, 2007 7:50 AM >> To: [hidden email] >> Subject: [Elecraft] K3 Noise Blanker ahead or behind roofing filter? >> >> I have K2 SN 1031 and an IC-746PRO. Last week my next door neighbor >> brought home a large screen TV that looks to be the rear projection >> type. I didn't pay much attention to it as they unloaded it >> but now find >> it puts out lots of QRN. It puts out S9 on the PRO 60 HZ QRN >> on 20, 15, >> 10 6 and 2 meters. Those are the bands I have antennas that work. The >> noise blanker in theK2 and the PRO both eliminate this bad QRN right >> down to the background noise :-) when there are now strong >> signals on >> the band but when a strong station such as the W1AW code >> sessions come >> on 20 meters, (20 over 9 in ND), than the K2 using NB1 has problems 5 >> KHZ or so either side of W1AW. NB2 has problems up to 10 KHZ >> either side >> of W1AW and the PRO has problems 15 KHZ either side of W1AW >> :-( . Is the >> noise blanker on the K3 ahead of the roofing filter or behind the >> roofing filter. If it is behind the roofing filter buying a >> K3 might put >> me back on the air :-) but if it is ahead of the roofing filter >> than would I have the same problem as the K2 :-( ? I have >> looked at the >> FAQ part of the Elecraft K3 site and do not find the answer to this >> question. I just need a short answer so please do not start a long >> thread on my station or observations etc. >> >> 73 and thanks for the help. >> >> W0CZ >> _______________________________________________ >> 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 _______________________________________________ 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: K3 Noise Blanker ahead or behind roofing filter?
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In reply to this post by Kenneth Christiansen
Hi Ken,
The short answer is "both". The 1st I.F. noise blanker module is ahead of the roofing filters, so it can blank wideband pulse noise. It has a wide AGC range and various threshold and blanking width settings. There's also a DSP noise blanker *after* the roofing filters. This blanker has the advantage of not being modulated by signals outside the roofing filter bandwidth. Of course you can't use it in all cases, because the roofing filter stretches the pulses and thus requires longer blanking times. But I have some noise on 160 m that the DSP blanker suppresses by some 40 dB, making otherwise completely inaudible signals stand out clearly. We're also experimenting with reconstructive blanking algorithms to make the DSP blanker even more effective. The noise blanker LEVEL switch displays the parameters for both the hardware blanker and the DSP blanker on the VFO A and VFO B displays. You can then adjust either or both to see which is most effective on noise. The settings are stored on a per-band basis. 73, Wayne N6KR On Jun 12, 2007, at 4:50 AM, Kenneth A. Christiansen wrote: > Is the noise blanker on the K3 ahead of the roofing filter or behind > the roofing filter....? --- 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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Hello to all.
I am new to this group and in the market for a new rig. I had a keen eye on "another American brand" that recently released a new rig. But then the K3 popped up and made it to the top of my list. I have two questions, sorry if they have been covered before. 1) Is the K3 ready to ship to EU when the next batch is available (CE label)? 2) Is the aux RX input (beverages and RX loops) available in the 'standard' K3/100? Or do I need an option (like "ATU with 2nd Ant. Jack")? Thanks for the input. 73 de Franki ON5ZO / OQ5M _______________________________________________ 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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Hi Franki and thanks for the email.
I'm not sure about the first part of your question, will have to let Eric field that one, but I believe the answer is yes. In order to use the RX in/out you will need the KXV3 option. This provides the RX only connections as well as the in/out for transverter interfacing. I think it's only around $79 for that option. Welcome to the Elecraft group! ------------------------- 73, Greg - AB7R Whidbey Island WA NA-065 On Tue Jun 12 12:11 , "Franki ON5ZO" sent: >Hello to all. > >I am new to this group and in the market for a new rig. I had a keen eye on >"another American brand" that recently released a new rig. But then the K3 >popped up and made it to the top of my list. >I have two questions, sorry if they have been covered before. > >1) Is the K3 ready to ship to EU when the next batch is available (CE >label)? > >2) Is the aux RX input (beverages and RX loops) available in the 'standard' >K3/100? Or do I need an option (like "ATU with 2nd Ant. Jack")? > >Thanks for the input. > >73 de Franki ON5ZO / OQ5M > >_______________________________________________ >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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In reply to this post by Franki ON5ZO
On 6/12/07, Franki ON5ZO <[hidden email]> wrote:
> > 1) Is the K3 ready to ship to EU when the next batch is available (CE > label)? If you place an order now, you will have to wait until the second batch (September) or perhaps even the third now, for shipment. Fortunately the CE requirement does not apply, as it is a personal import. I'll leave it to someone else to answer your second question. -- Julian, G4ILO G4ILO's Shack: www.g4ilo.com K2 s/n: 392 K3 s/n: ??? _______________________________________________ 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
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
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Hallo Julian,
> Fortunately the CE requirement does not apply, as it is a personal import. AFAIK the CE marking is not always necessary for kits, otherwise whether personal import or not, the CE marking is always required, even for stuff like a penlight! The CE marking is not required for customs, but without it, it is highly questionable that you are allowed to operate the equipment, assuming it is not homebrew or a kit. I'm not a lawyer, so ymmv. vy 73 de toby -- DD5FZ, 4N6FZ (ex dj7mgq, dg5mgq, dd5fz) K2 #885, K2/100 #3248 K3/100 #??? (< #200) DOK C12, BCC, DL-QRP-AG _______________________________________________ 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: Re: K3 Noise Blanker ahead or behind roofing filter?
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In reply to this post by wayne burdick
Wayne:
Your mention of some reconstructive algorithms was very interesting to me. For some time, I've wondered if it would be possible to have a circuit which would regenerate a CW signal and play it back in a noise free environment. I'm not an engineer, but I seem to remember that work was done a number of years back with UARTs and the like to regenerate fading or noisy TTY signals and they seemed to work reasonably well. At the very least, such a system might provide considerably improved copy under heavy noise conditions. I don't know of any other radio currently using audio reconstruction. Perhaps it's because it doesn't work or hasn't been high on the priority list. In any case, I think it's a very interesting idea. Bruce -- W8FU -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of wayne burdick Sent: Tuesday, June 12, 2007 11:58 AM To: Kenneth A. Christiansen Cc: [hidden email] Subject: [Elecraft] Re: K3 Noise Blanker ahead or behind roofing filter? Hi Ken, The short answer is "both". The 1st I.F. noise blanker module is ahead of the roofing filters, so it can blank wideband pulse noise. It has a wide AGC range and various threshold and blanking width settings. There's also a DSP noise blanker *after* the roofing filters. This blanker has the advantage of not being modulated by signals outside the roofing filter bandwidth. Of course you can't use it in all cases, because the roofing filter stretches the pulses and thus requires longer blanking times. But I have some noise on 160 m that the DSP blanker suppresses by some 40 dB, making otherwise completely inaudible signals stand out clearly. We're also experimenting with reconstructive blanking algorithms to make the DSP blanker even more effective. The noise blanker LEVEL switch displays the parameters for both the hardware blanker and the DSP blanker on the VFO A and VFO B displays. You can then adjust either or both to see which is most effective on noise. The settings are stored on a per-band basis. 73, Wayne N6KR On Jun 12, 2007, at 4:50 AM, Kenneth A. Christiansen wrote: > Is the noise blanker on the K3 ahead of the roofing filter or behind > the roofing filter....? --- 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 _______________________________________________ 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: Re: K3 Noise Blanker ahead or behind roofing filter?
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Bruce McLaughlin <[hidden email]> wrote:
> I don't know of any other radio currently > using audio reconstruction. Perhaps it's because it doesn't work or > hasn't been high on the priority list. In any case, I think it's a very > interesting idea. ---------------------------------------------------------------- A possible reason for this might be that it becomes quite "boring" to listen to QRM and noise free CW signals after a while, putting audio reconstruction low on the priority list. However it is a very useful tool to have when searching for beacons or other signals at or just below the receiver plus antenna noise floor on 10m and higher frequencies. 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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