Re: [Elecraft] P3 Phase noise/HighSignal Response?
On Tue,3/14/2017 8:19 AM, K5MWR via Elecraft wrote: Jim Really appreciate this information and going over it now to make sure I understand the limits. The presentation is well done. Thanks. But it's not really a presentation, just an easy way to display the data. How did you capture the SVGA images? I plugged a USB memory stick into the P3 USB port. There's a menu selection to do the capture. I assigned it to one of the soft buttons. 73, Jim K9YC Dave K5MWR On 3/13/2017 10:53 PM, Jim Brown wrote: Hi Dave, The P3 is quite good for measurements, and the SVGA card is even better. Here's a collection of work I've done with whatever rigs and amps I could get my hands on to measure. http://k9yc.com/P3_Spectrum_Measurements.pdf In my experience, if you keep the K3 within its linear region, you'll get good data from the P3 if you understand the measurements you're making. Limitations -- the dynamic range is 100 dB, but you can only display 80 dB on screen. For all of the operation I do, I use the P3 with a lot of averaging and a slow waterfall, fairly large waterfall. For measurements, I use the P3 in Peak reading mode and let it accumulate peaks for a while. I make the amplitude display pretty large, set it for 80 dB, and adjust levels to fill the amplitude screen. When I'm checking CW bandwidth, I send a series of dits in the range of 35 WPM for at least 20 seconds I reset the peak a second or so after I've started sending dits so I don't see any initial transient that might be present. Notice that I set the span for a fairly narrow bandwidth. The annotations you see for bandwidth are obtained by moving the cursor to each data point and writing down the readings, and they are the DIFFERENCE between the high and low points. If you want to show data more than 80 dB below the peak of the signal, you can repeat the measurement with the reference level reduced by 20 dB. More than that and the P3 will overload. 73, Jim K9YC On Mon,3/13/2017 6:03 PM, K5MWR via Elecraft wrote: I am trying to use my P3 to evaluate signals from other hams here in my community. While I know the K3s is excellent, I am not sure what to expect out of the P3 in terms of phase noise or response under high signal conditions. I can always pad to lower the signal but that will not help with any P3 internal phase. __ 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 Message delivered to k5mwr_...@yahoo.com __ 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 Message delivered to j...@audiosystemsgroup.com __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] P3 Phase noise/HighSignal Response?
Jim Really appreciate this information and going over it now to make sure I understand the limits. The presentation is well done. How did you capture the SVGA images? Dave K5MWR On 3/13/2017 10:53 PM, Jim Brown wrote: Hi Dave, The P3 is quite good for measurements, and the SVGA card is even better. Here's a collection of work I've done with whatever rigs and amps I could get my hands on to measure. http://k9yc.com/P3_Spectrum_Measurements.pdf In my experience, if you keep the K3 within its linear region, you'll get good data from the P3 if you understand the measurements you're making. Limitations -- the dynamic range is 100 dB, but you can only display 80 dB on screen. For all of the operation I do, I use the P3 with a lot of averaging and a slow waterfall, fairly large waterfall. For measurements, I use the P3 in Peak reading mode and let it accumulate peaks for a while. I make the amplitude display pretty large, set it for 80 dB, and adjust levels to fill the amplitude screen. When I'm checking CW bandwidth, I send a series of dits in the range of 35 WPM for at least 20 seconds I reset the peak a second or so after I've started sending dits so I don't see any initial transient that might be present. Notice that I set the span for a fairly narrow bandwidth. The annotations you see for bandwidth are obtained by moving the cursor to each data point and writing down the readings, and they are the DIFFERENCE between the high and low points. If you want to show data more than 80 dB below the peak of the signal, you can repeat the measurement with the reference level reduced by 20 dB. More than that and the P3 will overload. 73, Jim K9YC On Mon,3/13/2017 6:03 PM, K5MWR via Elecraft wrote: I am trying to use my P3 to evaluate signals from other hams here in my community. While I know the K3s is excellent, I am not sure what to expect out of the P3 in terms of phase noise or response under high signal conditions. I can always pad to lower the signal but that will not help with any P3 internal phase. __ 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 Message delivered to k5mwr_...@yahoo.com __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] P3 Phase noise/HighSignal Response?
Hi Dave, The P3 is quite good for measurements, and the SVGA card is even better. Here's a collection of work I've done with whatever rigs and amps I could get my hands on to measure. http://k9yc.com/P3_Spectrum_Measurements.pdf In my experience, if you keep the K3 within its linear region, you'll get good data from the P3 if you understand the measurements you're making. Limitations -- the dynamic range is 100 dB, but you can only display 80 dB on screen. For all of the operation I do, I use the P3 with a lot of averaging and a slow waterfall, fairly large waterfall. For measurements, I use the P3 in Peak reading mode and let it accumulate peaks for a while. I make the amplitude display pretty large, set it for 80 dB, and adjust levels to fill the amplitude screen. When I'm checking CW bandwidth, I send a series of dits in the range of 35 WPM for at least 20 seconds I reset the peak a second or so after I've started sending dits so I don't see any initial transient that might be present. Notice that I set the span for a fairly narrow bandwidth. The annotations you see for bandwidth are obtained by moving the cursor to each data point and writing down the readings, and they are the DIFFERENCE between the high and low points. If you want to show data more than 80 dB below the peak of the signal, you can repeat the measurement with the reference level reduced by 20 dB. More than that and the P3 will overload. 73, Jim K9YC On Mon,3/13/2017 6:03 PM, K5MWR via Elecraft wrote: I am trying to use my P3 to evaluate signals from other hams here in my community. While I know the K3s is excellent, I am not sure what to expect out of the P3 in terms of phase noise or response under high signal conditions. I can always pad to lower the signal but that will not help with any P3 internal phase. __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] P3 Phase noise/HighSignal Response?
I am trying to use my P3 to evaluate signals from other hams here in my community. While I know the K3s is excellent, I am not sure what to expect out of the P3 in terms of phase noise or response under high signal conditions. I can always pad to lower the signal but that will not help with any P3 internal phase. Any experiences? Dave K5MWR __ 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 Message delivered to arch...@mail-archive.com
