[Elecraft] P3 Misbehaving?
Just assembled P3 a few days ago. Having a problem that I can't seem to solve. Background: Haven't done K3 OUT mod yet (SN 113 fairly old) ... really am apprehensive about opening up K3 again ... but I know I'm just being neurotic ... will face any weekend now). The P3 was pretty much performing as expected ... given that I haven't done the above mode yet, and I live in manhattan with a mediocre hamstick hung outside my window .. I could generally see strongest stations above a lot of noise on P3. That was good. But over past few days, it seems that the sensitivity of the device was diminishing .. started to have trouble seeing the few stations that I could actually hear above the noise on my K3 ... and then today, it now appears that the P3 is basically deaf to the K3 ... I see some low ampitude noise, which doesn't vary in appearance with or without the coax cable to the IF OUT of the K3 plugged in. I am listening to a fairly strong Italian CW station now on 20 meters now, sticking his head above the omnipresent S5-6 noise ... armchair copy, if you will, but all I see is noise at the bottom of the P3 screen. The center frequency tracks my K3 nicely ... but no matter how I adjust the REF, SCALE and SPAN, all I see is noise. Any thoughts would be welcome. Yes, I will dive in and do the IF OUT mod, but am trying to understand the curious behavior, and to see if it sounds familiar to anyone. Thanks in advance -- WB2SSB Joseph J. Sanger, M.D. Associate Professor of Radiology Director, Radiology Informatics This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email. = __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] P3 Misbehaving?
Idea: Change in propagation causes different band noise levels. Same with geomagnetic activity, number of neighbors in the building, you name it. matt W6NIA K3 #24 P3 #14 On Sat, 11 Sep 2010 18:34:26 -0400, you wrote: Just assembled P3 a few days ago. Having a problem that I can't seem to solve. Background: Haven't done K3 OUT mod yet (SN 113 fairly old) ... really am apprehensive about opening up K3 again ... but I know I'm just being neurotic ... will face any weekend now). The P3 was pretty much performing as expected ... given that I haven't done the above mode yet, and I live in manhattan with a mediocre hamstick hung outside my window .. I could generally see strongest stations above a lot of noise on P3. That was good. But over past few days, it seems that the sensitivity of the device was diminishing .. started to have trouble seeing the few stations that I could actually hear above the noise on my K3 ... and then today, it now appears that the P3 is basically deaf to the K3 ... I see some low ampitude noise, which doesn't vary in appearance with or without the coax cable to the IF OUT of the K3 plugged in. I am listening to a fairly strong Italian CW station now on 20 meters now, sticking his head above the omnipresent S5-6 noise ... armchair copy, if you will, but all I see is noise at the bottom of the P3 screen. The center frequency tracks my K3 nicely ... but no matter how I adjust the REF, SCALE and SPAN, all I see is noise. Any thoughts would be welcome. Yes, I will dive in and do the IF OUT mod, but am trying to understand the curious behavior, and to see if it sounds familiar to anyone. Thanks in advance -- WB2SSB Joseph J. Sanger, M.D. Associate Professor of Radiology Director, Radiology Informatics This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email. = __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net 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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] P3 Misbehaving?
Is the noise floor on the P3 stuck at -140 dBm or so all the time, no matter what? I experienced a similar problem after 2 weeks of use, and replacement of the P3 RF board was required. Apparently, I was informed, another cause can be handling damage to transformers T100 or T101 on the P3 Front Panel board, so you might take a look at them. I sure wish the P3 schematic was available at the time, it would have made troubleshooting a little easier (it's still not published AFAICS). As usual, Elecraft support was prompt and efficient, I'd contact them if there's no change. Bob NW8L On Sat, Sep 11, 2010 at 4:34 PM, Sanger, Joseph joseph.san...@nyumc.org wrote: Just assembled P3 a few days ago. Having a problem that I can't seem to solve. Background: Haven't done K3 OUT mod yet (SN 113 fairly old) ... really am apprehensive about opening up K3 again ... but I know I'm just being neurotic ... will face any weekend now). The P3 was pretty much performing as expected ... given that I haven't done the above mode yet, and I live in manhattan with a mediocre hamstick hung outside my window .. I could generally see strongest stations above a lot of noise on P3. That was good. But over past few days, it seems that the sensitivity of the device was diminishing .. started to have trouble seeing the few stations that I could actually hear above the noise on my K3 ... and then today, it now appears that the P3 is basically deaf to the K3 ... I see some low ampitude noise, which doesn't vary in appearance with or without the coax cable to the IF OUT of the K3 plugged in. I am listening to a fairly strong Italian CW station now on 20 meters now, sticking his head above the omnipresent S5-6 noise ... armchair copy, if you will, but all I see is noise at the bottom of the P3 screen. The center frequency tracks my K3 nicely ... but no matter how I adjust the REF, SCALE and SPAN, all I see is noise. Any thoughts would be welcome. Yes, I will dive in and do the IF OUT mod, but am trying to understand the curious behavior, and to see if it sounds familiar to anyone. Thanks in advance -- WB2SSB Joseph J. Sanger, M.D. Associate Professor of Radiology Director, Radiology Informatics __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] P3 Misbehaving?
and then today, it now appears that the P3 is basically deaf to the K3 ... I see some low ampitude noise, which doesn't vary in appearance with or without the coax cable to the IF OUT of the K3 plugged in. OM, On a K3 with the IF OUT modification, you should definitely see the noise level on the P3 go down when you disconnect the coax that goes from the K3 IF OUT to the P3 IF IN. I don't have a K3 without the mod to test with, but I'm pretty sure that, even in that case, if you turn on the K3's preamp you should still see a change in noise level when you disconnect the coax. If not, there is something wrong. First check the coax cable to be sure it is properly seated at both the K3 and P3 end. If you have another BNC coax cable available you might try it to see if the problem is a bad cable. You could also pop the top off the P3 and check the small coax cable that goes from the rear-panel amplifier board to the Front Panel board. Push with a twisting motion on the connector on each end to be sure it is well-seated in the receptacle. (On the amplifier board, support the board with your fingers while you do this to avoid flexing the board.) If none of that helps I would contact Elecraft customer support and get their recommendations on the next step. Alan N1AL On Sat, 2010-09-11 at 18:34 -0400, Sanger, Joseph wrote: Just assembled P3 a few days ago. Having a problem that I can't seem to solve. Background: Haven't done K3 OUT mod yet (SN 113 fairly old) ... really am apprehensive about opening up K3 again ... but I know I'm just being neurotic ... will face any weekend now). The P3 was pretty much performing as expected ... given that I haven't done the above mode yet, and I live in manhattan with a mediocre hamstick hung outside my window .. I could generally see strongest stations above a lot of noise on P3. That was good. But over past few days, it seems that the sensitivity of the device was diminishing .. started to have trouble seeing the few stations that I could actually hear above the noise on my K3 ... and then today, it now appears that the P3 is basically deaf to the K3 ... I see some low ampitude noise, which doesn't vary in appearance with or without the coax cable to the IF OUT of the K3 plugged in. I am listening to a fairly strong Italian CW station now on 20 meters now, sticking his head above the omnipresent S5-6 noise ... armchair copy, if you will, but all I see is noise at the bottom of the P3 screen. The center frequency tracks my K3 nicely ... but no matter how I adjust the REF, SCALE and SPAN, all I see is noise. Any thoughts would be welcome. Yes, I will dive in and do the IF OUT mod, but am trying to understand the curious behavior, and to see if it sounds familiar to anyone. Thanks in advance -- WB2SSB Joseph J. Sanger, M.D. Associate Professor of Radiology Director, Radiology Informatics This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email. = __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net 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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] P3 Misbehaving?
The noise floor shifts by 10 db each time I make a change to the PRE or ATT switch ... resulting in 3 separate noise floor levels. But you are right, the RF board turned out to be the problem! You will see on my next post, the final chapter. Thanks very much, Bob. -Original Message- From: Bob Cunnings [mailto:bob.cunni...@gmail.com] Sent: Saturday, September 11, 2010 8:10 PM To: Sanger, Joseph Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] P3 Misbehaving? Is the noise floor on the P3 stuck at -140 dBm or so all the time, no matter what? I experienced a similar problem after 2 weeks of use, and replacement of the P3 RF board was required. Apparently, I was informed, another cause can be handling damage to transformers T100 or T101 on the P3 Front Panel board, so you might take a look at them. I sure wish the P3 schematic was available at the time, it would have made troubleshooting a little easier (it's still not published AFAICS). As usual, Elecraft support was prompt and efficient, I'd contact them if there's no change. Bob NW8L On Sat, Sep 11, 2010 at 4:34 PM, Sanger, Joseph joseph.san...@nyumc.org wrote: Just assembled P3 a few days ago. Having a problem that I can't seem to solve. Background: Haven't done K3 OUT mod yet (SN 113 fairly old) ... really am apprehensive about opening up K3 again ... but I know I'm just being neurotic ... will face any weekend now). The P3 was pretty much performing as expected ... given that I haven't done the above mode yet, and I live in manhattan with a mediocre hamstick hung outside my window .. I could generally see strongest stations above a lot of noise on P3. That was good. But over past few days, it seems that the sensitivity of the device was diminishing .. started to have trouble seeing the few stations that I could actually hear above the noise on my K3 ... and then today, it now appears that the P3 is basically deaf to the K3 ... I see some low ampitude noise, which doesn't vary in appearance with or without the coax cable to the IF OUT of the K3 plugged in. I am listening to a fairly strong Italian CW station now on 20 meters now, sticking his head above the omnipresent S5-6 noise ... armchair copy, if you will, but all I see is noise at the bottom of the P3 screen. The center frequency tracks my K3 nicely ... but no matter how I adjust the REF, SCALE and SPAN, all I see is noise. Any thoughts would be welcome. Yes, I will dive in and do the IF OUT mod, but am trying to understand the curious behavior, and to see if it sounds familiar to anyone. Thanks in advance -- WB2SSB Joseph J. Sanger, M.D. Associate Professor of Radiology Director, Radiology Informatics This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email. = __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] P3 Misbehaving?
Matt, you are right ... I thought the K3 was dead ... but part of the problem is band conditions ... thanks for the comment. -Original Message- From: Matt Zilmer [mailto:mzil...@verizon.net] Sent: Saturday, September 11, 2010 7:40 PM To: Sanger, Joseph Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] P3 Misbehaving? Idea: Change in propagation causes different band noise levels. Same with geomagnetic activity, number of neighbors in the building, you name it. matt W6NIA K3 #24 P3 #14 On Sat, 11 Sep 2010 18:34:26 -0400, you wrote: Just assembled P3 a few days ago. Having a problem that I can't seem to solve. Background: Haven't done K3 OUT mod yet (SN 113 fairly old) ... really am apprehensive about opening up K3 again ... but I know I'm just being neurotic ... will face any weekend now). The P3 was pretty much performing as expected ... given that I haven't done the above mode yet, and I live in manhattan with a mediocre hamstick hung outside my window .. I could generally see strongest stations above a lot of noise on P3. That was good. But over past few days, it seems that the sensitivity of the device was diminishing .. started to have trouble seeing the few stations that I could actually hear above the noise on my K3 ... and then today, it now appears that the P3 is basically deaf to the K3 ... I see some low ampitude noise, which doesn't vary in appearance with or without the coax cable to the IF OUT of the K3 plugged in. I am listening to a fairly strong Italian CW station now on 20 meters now, sticking his head above the omnipresent S5-6 noise ... armchair copy, if you will, but all I see is noise at the bottom of the P3 screen. The center frequency tracks my K3 nicely ... but no matter how I adjust the REF, SCALE and SPAN, all I see is noise. Any thoughts would be welcome. Yes, I will dive in and do the IF OUT mod, but am trying to understand the curious behavior, and to see if it sounds familiar to anyone. Thanks in advance -- WB2SSB Joseph J. Sanger, M.D. Associate Professor of Radiology Director, Radiology Informatics This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email. = __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email. = __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] P3 Misbehaving?
Well, I am happy / embarrassed to say, problem solved. Alan, your troubleshooting tips led me to the solution. I am closing the loop on this, in spite of my embarrassment, in order to possibly save someone else this problem. The problem was simply carelessness on my part. I had installed the RF board upside down ... guess what, it physically fits either right side up or upside down .. the only apparent difference visually, from the back at least, is that the little dual-position switch ... doesn't poke out of the back slot when you install board upside down. D'oh! Flipping it right-side up solved my problem. What is odd is that it ever _sort_ of worked in the upside/down position. Well, thanks to all who offered comments ... I REALLY appreciate it. -- Joe -- WB2SSB -Original Message- From: Alan Bloom [mailto:n...@cds1.net] Sent: Saturday, September 11, 2010 9:04 PM To: Sanger, Joseph Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] P3 Misbehaving? and then today, it now appears that the P3 is basically deaf to the K3 ... I see some low ampitude noise, which doesn't vary in appearance with or without the coax cable to the IF OUT of the K3 plugged in. OM, On a K3 with the IF OUT modification, you should definitely see the noise level on the P3 go down when you disconnect the coax that goes from the K3 IF OUT to the P3 IF IN. I don't have a K3 without the mod to test with, but I'm pretty sure that, even in that case, if you turn on the K3's preamp you should still see a change in noise level when you disconnect the coax. If not, there is something wrong. First check the coax cable to be sure it is properly seated at both the K3 and P3 end. If you have another BNC coax cable available you might try it to see if the problem is a bad cable. You could also pop the top off the P3 and check the small coax cable that goes from the rear-panel amplifier board to the Front Panel board. Push with a twisting motion on the connector on each end to be sure it is well-seated in the receptacle. (On the amplifier board, support the board with your fingers while you do this to avoid flexing the board.) If none of that helps I would contact Elecraft customer support and get their recommendations on the next step. Alan N1AL On Sat, 2010-09-11 at 18:34 -0400, Sanger, Joseph wrote: Just assembled P3 a few days ago. Having a problem that I can't seem to solve. Background: Haven't done K3 OUT mod yet (SN 113 fairly old) ... really am apprehensive about opening up K3 again ... but I know I'm just being neurotic ... will face any weekend now). The P3 was pretty much performing as expected ... given that I haven't done the above mode yet, and I live in manhattan with a mediocre hamstick hung outside my window .. I could generally see strongest stations above a lot of noise on P3. That was good. But over past few days, it seems that the sensitivity of the device was diminishing .. started to have trouble seeing the few stations that I could actually hear above the noise on my K3 ... and then today, it now appears that the P3 is basically deaf to the K3 ... I see some low ampitude noise, which doesn't vary in appearance with or without the coax cable to the IF OUT of the K3 plugged in. I am listening to a fairly strong Italian CW station now on 20 meters now, sticking his head above the omnipresent S5-6 noise ... armchair copy, if you will, but all I see is noise at the bottom of the P3 screen. The center frequency tracks my K3 nicely ... but no matter how I adjust the REF, SCALE and SPAN, all I see is noise. Any thoughts would be welcome. Yes, I will dive in and do the IF OUT mod, but am trying to understand the curious behavior, and to see if it sounds familiar to anyone. Thanks in advance -- WB2SSB Joseph J. Sanger, M.D. Associate Professor of Radiology Director, Radiology Informatics This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email. = __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] P3 Misbehaving?
Alan's advice is pertinent because I found my P3's BNC-to-BNC coax cable to be open... swapping it with a known good one laying in my cable drawer solved that problem. Just a warning for anybody else to go ahead and suspect the cable (as well as everything else) if you don't see what you expect to see on the P3. Al W6LX OM, First check the coax cable to be sure it is properly seated at both the K3 and P3 end. If you have another BNC coax cable available you might try it to see if the problem is a bad cable. Alan N1AL __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
