K3 Overload from WYFR
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A photo (40 meter Overload) has been uploaded to the file section of the
LP-PAN Yahoo Group. This photo is a screen capture from PowerSDR-IF showing WYFR at 6985Khz and the resulting images on either side of the carrier. The K3's preamp was off. Turning on ATTN reduces the levels somewhat but the images are still present. These images can be seen on PowerSDR all the way up to about 7080kHz while WYFR is transmitting however, tuning the K3's VFO to 7030kHz or above eliminates all signs of these images. Buckshot (distorted bits of modulation) can be heard up to about 7015Khz. The images shown seem to be generated by the LP-PAN. Clicking on them moves them elsewhere and they cannot be heard. Other than the buckshot at the low end of 40 meters, audible reception seems to be unaffected however LP-PAN is rendered unusable during the evenings. WYFR is located in Okeechobee, Florida, 631 miles from my QTH in NC. Naturally their signal is very strong, 60db+ over S9. The antenna used here is a 200ft doublet, ladder line and tuner. Here are my questions and concerns: 1. Is it normal to expect the K3's front end to overload under these conditions? 2. Is it normal for LP-Pan to be rendered useless by strong BC stations outside the ham bands like this? 3. Do you think this could be caused by any defect in the K3 or station configuration? 4. What kind, if any, outboard filter would help? The internal or external tuner has no effect (in or out of circuit). 5. Is anyone else experiencing such an overload? I'm just trying to pin down exactly where the problem is. It appears that the front end in the K3 is allowing too strong of a signal to hit the LP-PAN then the K3's roofing filters do their job to protect the K3's DSP. I have become rather addicted to the LP-PAN. I can't tell how many times I have though the band was dead after carefully tuning but a quick glance at the screen reveals several stations! If you are not subscribed to the LP-PAN group, you may view the photo here: http://i222.photobucket.com/albums/dd260/n4lq/wyfr.jpg 73 Steve N4LQ [hidden email] ______________________________________________________________ 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 |
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> 1. Is it normal to expect the K3's front end to overload under these
> conditions? Are you sure the K3 front end is overloading and not the LP-PAN system (QSD, attached soundcard)? Are you experiencing symptoms that suggest reh K3 front end is overloading other than the LP-PAN display (which may be displaying the LP-PAN system, and in particular the soundcard ADC, overloading)? You might try adding an attenuator between the K3 IF out and the LP-PAN IF in and see if the overloading disappears. If so, it might indicate the LP-PAN system is overloading rather than the K3. 73, Lyle KK7P PS - The K3 blocking dynamic range is 20 to 30 dB better than PC-based SDRs. So I suspect you are seeing a weakness in the PC-based SDR system rather than the K3, but I've been wrong before! :-) ______________________________________________________________ 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 |
Re: [LP-PAN] Re: K3 Overload from WYFR
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Lyle: Yes I do believe the LP-PAN is being overloaded but still, I do hear that buckshot modulation from WYFR up to about 7010kHz on the K3 so it too is being affected although not as much.
N4LQ Steve [hidden email] ----- Original Message ----- From: Lyle Johnson To: Steve Ellington Cc: [hidden email] ; [hidden email] Sent: Sunday, June 14, 2009 8:46 PM Subject: [LP-PAN] Re: [Elecraft] K3 Overload from WYFR > 1. Is it normal to expect the K3's front end to overload under these > conditions? Are you sure the K3 front end is overloading and not the LP-PAN system (QSD, attached soundcard)? Are you experiencing symptoms that suggest reh K3 front end is overloading other than the LP-PAN display (which may be displaying the LP-PAN system, and in particular the soundcard ADC, overloading)? You might try adding an attenuator between the K3 IF out and the LP-PAN IF in and see if the overloading disappears. If so, it might indicate the LP-PAN system is overloading rather than the K3. 73, Lyle KK7P PS - The K3 blocking dynamic range is 20 to 30 dB better than PC-based SDRs. So I suspect you are seeing a weakness in the PC-based SDR system rather than the K3, but I've been wrong before! :-) __._,_.___ Messages in this topic (2) Reply (via web post) | Start a new topic Messages | Files | Photos | Links | Database | Polls | Members | Calendar Change settings via the Web (Yahoo! ID required) Change settings via email: Switch delivery to Daily Digest | Switch format to Traditional Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe Recent Activity a.. 7New Members b.. 1New Photos Visit Your Group Give Back Yahoo! for Good Get inspired by a good cause. Y! Toolbar Get it Free! easy 1-click access to your groups. Yahoo! Groups Start a group in 3 easy steps. Connect with others. . __,_._,___ ______________________________________________________________ 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 |
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An AM station can easily produce "buckshot" to 40-50 kcs's out. The
reason you don't hear it very often in the US, is that on the standard AM band, the AM stations are very bandwidth limited. The NRSC curve is rather tight, and every AM station has to certify it is within that mask every 14 months or so. I'm not sure of this, but I think US shortwave stations are not required to have any NRSC type filtering. Hence, the buckshot can go a long ways. Disconnect the LP-PAN, and measure/estimate the signal strength of the buckshot at, say, 7005. Now, turn on the attenuator. If the level of the buckshot drops by the level of the attenuator, then the radio station is producing the buckshot. If the attenuated level drops 2 to 5 times more than the added attenuation, that then shows that the K3 is overloading. My Sunday night guess? The station is producing the buckshot. Just an increase of .3 Db drive after the audio limiter can make just about any transmitter produce garbage. Tom Bosscher K8TB broadcast engineer for 3.5 decades... Steve Ellington wrote: > Lyle: Yes I do believe the LP-PAN is being overloaded but still, I do hear that buckshot modulation from WYFR up to about 7010kHz on the K3 so it too is being affected although not as much. > ______________________________________________________________ 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 |
Re: [LP-PAN] Re: K3 Overload from WYFR
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Thanks for the tip. I disconnected the LP-Pan and didn't notice any
difference in the buckshot level. I really can't judge what the S meter is telling me due to QRN etc. but when ATT is engaged, the QRN drops down somewhat but the buckshot actually comes through more clearly. Steve Ellington [hidden email] ----- Original Message ----- From: "K8TB" <[hidden email]> To: "Steve Ellington" <[hidden email]>; "'Elecraft Reflector'" <[hidden email]> Sent: Sunday, June 14, 2009 9:23 PM Subject: Re: [Elecraft] [LP-PAN] Re: K3 Overload from WYFR > An AM station can easily produce "buckshot" to 40-50 kcs's out. The > reason you don't hear it very often in the US, is that on the standard AM > band, the AM stations are very bandwidth limited. The NRSC curve is rather > tight, and every AM station has to certify it is within that mask every 14 > months or so. > I'm not sure of this, but I think US shortwave stations are not > required to have any NRSC type filtering. Hence, the buckshot can go a > long ways. > > Disconnect the LP-PAN, and measure/estimate the signal strength of the > buckshot at, say, 7005. Now, turn on the attenuator. If the level of the > buckshot drops by the level of the attenuator, then the radio station is > producing the buckshot. If the attenuated level drops 2 to 5 times more > than the added attenuation, that then shows that the K3 is overloading. > > My Sunday night guess? The station is producing the buckshot. Just an > increase of .3 Db drive after the audio limiter can make just about any > transmitter produce garbage. > > Tom Bosscher K8TB broadcast engineer for 3.5 decades... > > > Steve Ellington wrote: >> Lyle: Yes I do believe the LP-PAN is being overloaded but still, I do >> hear that buckshot modulation from WYFR up to about 7010kHz on the K3 so >> it too is being affected although not as much. > ______________________________________________________________ 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 |
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In reply to this post by Steve Ellington
Well, they are trying to SPREAD god's word.
--- On Sun, 6/14/09, Steve Ellington <[hidden email]> wrote: From: Steve Ellington <[hidden email]> Subject: Re: [Elecraft] [LP-PAN] Re: K3 Overload from WYFR To: [hidden email] Cc: [hidden email], [hidden email] Date: Sunday, June 14, 2009, 7:01 PM Lyle: Yes I do believe the LP-PAN is being overloaded but still, I do hear that buckshot modulation from WYFR up to about 7010kHz on the K3 so it too is being affected although not as much. N4LQ Steve ______________________________________________________________ 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 |
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In reply to this post by Steve Ellington
I would be checking your system (including the antenna and nearby structures) for problems ... I'm a whole lot closer to WYFR (105 miles) and they do not generate any overload or "buckshot" on my K3 with SDR-IQ and SpectraVue. 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Steve Ellington > Sent: Sunday, June 14, 2009 8:32 PM > To: [hidden email]; [hidden email] > Subject: [Elecraft] K3 Overload from WYFR > > > A photo (40 meter Overload) has been uploaded to the file > section of the > LP-PAN Yahoo Group. This photo is a screen capture from > PowerSDR-IF showing > WYFR at 6985Khz and the resulting images on either side of > the carrier. The > K3's preamp was off. Turning on ATTN reduces the levels > somewhat but the > images are still present. These images can be seen on > PowerSDR all the way > up to about 7080kHz while WYFR is transmitting however, > tuning the K3's VFO > to 7030kHz or above eliminates all signs of these images. Buckshot > (distorted bits of modulation) can be heard up to about > 7015Khz. The images shown seem to be generated by the LP-PAN. > Clicking on them moves > them elsewhere and they cannot be heard. Other than the > buckshot at the low > end of 40 meters, audible reception seems to be unaffected > however LP-PAN is > rendered unusable during the evenings. > WYFR is located in Okeechobee, Florida, 631 miles from my QTH in NC. > Naturally their signal is very strong, 60db+ over S9. The > antenna used here > is a 200ft doublet, ladder line and tuner. > Here are my questions and concerns: > 1. Is it normal to expect the K3's front end to overload under these > conditions? > 2. Is it normal for LP-Pan to be rendered useless by strong > BC stations > outside the ham bands like this? > 3. Do you think this could be caused by any defect in the K3 > or station > configuration? > 4. What kind, if any, outboard filter would help? The > internal or external > tuner has no effect (in or out of circuit). > 5. Is anyone else experiencing such an overload? > I'm just trying to pin down exactly where the problem is. It > appears that > the front end in the K3 is allowing too strong of a signal to > hit the LP-PAN > then the K3's roofing filters do their job to protect the > K3's DSP. I have become rather addicted to the LP-PAN. I > can't tell how many times I > have though the band was dead after carefully tuning but a > quick glance at > the screen reveals several stations! > If you are not subscribed to the LP-PAN group, you may view > the photo here: > http://i222.photobucket.com/albums/dd260/n4lq/wyfr.jpg > > 73 Steve N4LQ > > [hidden email] > > ______________________________________________________________ > 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 |
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You are using a doublet and tuner: to what frequency is the tuner tuned? Do
you get the same response if the tuner is set differently? Further to Joe's suggestion: I've heard of a strong local signal being rectified in rusty guttering giving problems to a beam in just one direction. Took years to find that one. David G3UNA > > I would be checking your system (including the antenna and > nearby structures) for problems ... I'm a whole lot closer > to WYFR (105 miles) and they do not generate any overload > or "buckshot" on my K3 with SDR-IQ and SpectraVue. > > 73, > > ... Joe, W4TV > > 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 |
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> Further to Joe's suggestion: I've heard of a strong local signal being
> rectified in rusty guttering giving problems to a beam in just one > direction. Took years to find that one. Reminds me of something which happened many years ago here in Southern Germany. The interference monitoring and abatement service (at the time they were part of the German Post Office) received several complaints about TVI. The nearest ham was about 2km distant and when they checked his transmitter, the signal was clean. When they measured at the TV receiver there was a large harmonic on the same frequency as one of the TV stations. It turned out that one of the ham's neighbours had a narrow band, high gain television reception Yagi pointing towards the 2km distant TV. It turned out that there was some oxidation at the feed point of the Yagi, which acted as a diode. As you can imagine, this is the very short version of this true story. vy 73 de toby, DD5FZ ______________________________________________________________ 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 |
Re: [LP-PAN] Re: K3 Overload from WYFR
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In reply to this post by Steve Ellington
Steve,
Although a long shot, among the possible causes of your problem is a defective roofing filter, defective in terms of signal handling capability but otherwise OK. To eliminate this possibility, have you tried switching roofing filters with the LP-Pan disconnected? 73, Geoff GM4ESD ----- Original Message ----- Steve Ellington" <[hidden email]> To: <[hidden email]>; "'Elecraft Reflector'" <[hidden email]> Sent: Monday, June 15, 2009 2:37 AM Subject: Re: [Elecraft] [LP-PAN] Re: K3 Overload from WYFR > Thanks for the tip. I disconnected the LP-Pan and didn't notice any > difference in the buckshot level. I really can't judge what the S meter is > telling me due to QRN etc. but when ATT is engaged, the QRN drops down > somewhat but the buckshot actually comes through more clearly. > Steve Ellington > [hidden email] ______________________________________________________________ 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 |
K2 translator for the white sticker
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In reply to this post by dj7mgq
One of my HAM friends is white sticker. He would be happy to get a K2 usable
for portable operation without any PC. I posted his problem to the German QRP Forum, asking for help. My idea was to get an ASCII / CW Interface KISS, the number of keys kept as low as possible. Norbert DK6NF very fast designed a little box containing an Atmel Processor which translates the ASCII IN/OUT of the K2 into CW code. Not all the possible commands, but at least the minimum information a blind OP needs to know where he starts. Only 4 keys: 1. sets VFO to A, responding an A in CW 2. Responding with VFO Frequency 3. Responding the Mode L / U / C and CR for CW Reverse 4. Responding the power Because I am sure this little translator would be helpful for some of our US Fellow QRPers as well, I post this info to let you participate the discussion. Do this Information make sense, or do you mean we need additional information. (which would cause more keys) 72/3 de Peter, DL2FI ______________________________________________________________ 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 |
Re: K2 translator for the white sticker
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That is a very interesting project, and I am sure you really enjoyed
creating the box. The KRC2ACC is expressly designed for this purpose. It reports almost all K2 information through CW, and has many key functions to let the op know just what is going on with the K2 and to maintain better control of the radio. We worked very closely with blind hams in its design, learning quite a bit from these great folks along the way. Of course, like its brother the KRC2, it can also perform antenna selection. Sounds like there are multiple ways to help folks use their Elecraft radios! Jack Brindle, W6FB Elecraft Engineering On Jun 15, 2009, at 7:34 AM, Peter, DL2FI wrote: > One of my HAM friends is white sticker. He would be happy to get a > K2 usable > for portable operation without any PC. I posted his problem to the > German > QRP Forum, asking for help. My idea was to get an ASCII / CW > Interface KISS, > the number of keys kept as low as possible. > > Norbert DK6NF very fast designed a little box containing an Atmel > Processor > which translates the ASCII IN/OUT of the K2 into CW code. Not all the > possible commands, but at least the minimum information a blind OP > needs to > know where he starts. > > Only 4 keys: > 1. sets VFO to A, responding an A in CW > 2. Responding with VFO Frequency > 3. Responding the Mode L / U / C and CR for CW Reverse > 4. Responding the power > > > Because I am sure this little translator would be helpful for some > of our US > Fellow QRPers as well, I post this info to let you participate the > discussion. > > Do this Information make sense, or do you mean we need additional > information. (which would cause more keys) > > 72/3 de Peter, DL2FI > > ______________________________________________________________ > 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 |
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In reply to this post by Steve Ellington
Hi Steve. Apparently there has been a problem with the messages to me from the LP-PAN Yahoo Group, so this digest is the first I am aware of your post. Sorry about that. I think it has been resolved now.
It sounds like you may have to check your gain setting in LP-PAN, as well as the input level on your sound card. LP-PAN should easily be able to handle S9 + 60dB when set properly. What is the noise floor you are seeing on other bands? Do you have the K3 buffer mod installed? If so, you may need to remove it, or add a pad between the K3 and LP-PAN. Where do you have the gain pot in LP-PAN set? It should be set for minimum in your case. If you turn the input level of the sound card way down, do you still see the clipping? If so, you need to reduce the gain setting in LP-PAN. The first step in solving this is determine where the clipping is happening (K3, LP-PAN or sound card). 73, Larry N8LP
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Re: K3 Overload from WYFR
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In reply to this post by KK7P
Hi Lyle,
> You might try adding an attenuator between the K3 IF out and the LP-PAN > IF in and see if the overloading disappears. If so, it might indicate > the LP-PAN system is overloading rather than the K3. > > 73, > > Lyle KK7P > > PS - The K3 blocking dynamic range is 20 to 30 dB better than PC-based > SDRs. So I suspect you are seeing a weakness in the PC-based SDR system > rather than the K3, but I've been wrong before! :-) I'll probably have to eat Humble Pie, but with respect I don't believe that Steve has an overload problem, but could have a spurious mixing problem, the result being similar to intermodulation. Also, the problem might or might not be caused by the K3 nor LP-PAN, which would not be difficult to determine if another receiver is available. The screen capture of WYFR's carrier at 6985 kHz, and a family of products, shows that the spacing product to adjacent product is roughly 4.64 kHz if the low level intermediate products are ignored, which they can be in this exercise. If these products are the result of mixing (or are IMD products), there has to be of course another signal spaced 4.64 kHz from WYFR's carrier - and there is one at 6980.36 kHz, whose amplitude fits the amplitude pattern of the products. Of course, the device or transmitter generating this signal at 6980.36 kHz might in fact be operating at a sub-harmonic frequency e.g. a MF BC station, and the rogue mixer itself is generating the 6980.36 kHz harmonic. 73, Geoff GM4ESD ______________________________________________________________ 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 |
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And the rogue mixer could be our old friends Rusty Bolt, Anode and Cathode.
David G3UNA > > Of course, the device or transmitter generating this signal at 6980.36 kHz > might in fact be operating at a sub-harmonic frequency e.g. a MF BC station, > *and the rogue mixer itself is generating the 6980.36 kHz harmonic.* > > 73, > Geoff > GM4ESD > ______________________________________________________________ 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 |
Re: K3 Overload from WYFR
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Yes indeed as both you and Joe, W4TV, have suggested before. Nickel plated
coax connectors can create similar problems. Geoff GM4ESD David G3UNA wrote on Tuesday, June 16, 2009 at 3:19 PM > And the rogue mixer could be our old friends Rusty Bolt, Anode and > Cathode. > > David > G3UNA >> >> Of course, the device or transmitter generating this signal at 6980.36 >> kHz >> might in fact be operating at a sub-harmonic frequency e.g. a MF BC >> station, > >> *and the rogue mixer itself is generating the 6980.36 kHz harmonic.* >> >> 73, >> Geoff >> GM4ESD >> > ______________________________________________________________ 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 |
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In reply to this post by Geoffrey Mackenzie-Kennedy
Hi All,
I was just wondering about the 40 m and started to listen to the AM broadcasts. I also found the nasty noises, but when I checked on the LP-Pan, I found the signal was ok. Of course, when I turned off the noise blanker it went away. Yet another senior moment. 73 Tim gm4lmh ______________________________________________________________ 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 |
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Tim Heasman wrote:
> Of course, when I turned off the noise blanker it went away. In many cases you can use the DSP noise blanker instead of the IF blanker. The DSP blanker has the advantage of the narrow crystal filter ahead of it, and in many cases this will eliminate wideband intermod. Or try the two combined, with a less-aggressive setting of the IF blanker. 73, Wayne N6KR --- http://www.elecraft.com ______________________________________________________________ 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 |
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