KX3 "Full" SDR
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Let's let this thread rest for now in the interest of reducing list email
overload for others. [Thread closed] 73 and have a great new year! Eric List Moderator, among other things.. elecraft.com Eric elecraft.com On 12/31/2013 4:13 PM, Bruce Beford wrote: >> I stand by my statement ... if everyone used FLEX SDR rigs (you do know >> that noise power is additive, right?) we'd all have a major problem. >> Dave AB7E > With that, I agree. > Bruce, N1RX > > > > ______________________________________________________________ > 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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Agreed.
HNY, Bruce, N1RX _____ From: Eric Swartz - WA6HHQ, Elecraft [mailto:[hidden email]] Sent: Tuesday, December 31, 2013 8:03 PM To: Bruce Beford; [hidden email] Subject: Re: [Elecraft] KX3 "Full" SDR Let's let this thread rest for now in the interest of reducing list email overload for others. [Thread closed] 73 and have a great new year! Eric List Moderator, among other things.. elecraft.com Eric elecraft.com On 12/31/2013 4:13 PM, Bruce Beford wrote: I stand by my statement ... if everyone used FLEX SDR rigs (you do know that noise power is additive, right?) we'd all have a major problem. Dave AB7E With that, I agree. Bruce, N1RX ______________________________________________________________ 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 Craig Schroeder
I am in general agreement with what Greg writes, below (but with some
comments inserted); Date: Tue, 31 Dec 2013 12:38:28 -0500 From: Greg Troxel <[hidden email]> To: Don Wilhelm <[hidden email]> Cc: [hidden email], Craig Schroeder <[hidden email]> Subject: Re: [Elecraft] KX3 "Full" SDR There are several important questions that could be lurking behing "full SDR", especially since Craig talked about hobby aspects of SDR -- people often mistakenly equate SDR with "open-source SDR", blurring "functions are controlled by software" with "user can control functions by software". 1) Is the modulation/demodulation done in some sort of processor under software control, from a wide IF (perhaps at 0, perhaps higher)? This is the normal definition, and indeed the KX3 meets it. 2) Is the user of the radio able to change the firmwmare, in order to experiment or for other purposes? One might call this "user-changeable SDR". Here, the KX3 does not meet that definition -- while Elecraft has released updates and improvements and can be expected to keep doing so, users cannot improve or even read the software. x-x-x-x-x-x-x Here I must insert a comment that commercial SDR's do not generally offer "open source" sw to their customers, either. This is a special issue that fits one of ham radios treasured activities of being able to "roll your own" and redesign everything! I would maintain this is a small group in ham radio (even for a tech guy like me). x-x-x-x-x-x-x 2a) Can someone who changes the firmware share their improvements with the world? This is a further nuance, leading to "open-source SDR". Flex used to be like this, but I understand (from speaking to a Flex rep at Boxboro 2012) that the software used with their radios is now proprietary rather than open source. x-x-x-x-x-x-x Probably Flex has learned the hard way that opening up everything to general access has a huge customer service headache attached! Again you will not find this offered in commercial or military SDR's. x-x-x-x-x-x-x And, it is limited to Windows only, which leads to an unreliable system (as described by a Flex user who gave a talk at a local club). Note that there is hardly any discussion of KX3s locking up and being flaky and needing to be rebooted. Then there's a related question separate from SDR definitions, having to do with packaging and interconnects: 3) Does the radio function without having to carry along an external computer? There is great merit in a small low-power box being functional by itself. x-x-x-x-x-x-x I would venture to say you will not see the military running around with radios that require a computer to operate - they may use one as an accessory like a typewriter. x-x-x-x-x-x-x Craig: So it really depends why you think you want an SDR. If you want to understand the software and contribute towards a community of people improving it, the KX3 won't let you do that, and I would suggest that you look at GNU Radio and other open-source projects and their associated hardware (some of which has open designs). If you want a radio which has features typically achievable in SDR, and that you can expect to be improved by the manufacturer, and you don't mind not being able to change it (and that others can't either), then the KX3 fits the bill. If what you want is to experiment with code to demodulate, the KX3 is also a good choice because it provides I/Q output. But I know of no way to transmit custom signals (other than soundcard modes, which generally are viewed as below the SDR definition). x-x-x-x-x-x-x Yes, the soundcard interface is kind of limiting but still valid. I would see better interfaces coming in the future. x-x-x-x-x-x-x My advice is to think about what you really want in terms of an experimentation/learning platform vs. a really well designed useful radio. And if you are going to experiment with code, stay within the open-source world, so that you can share your changes with everyone. x-x-x-x-x-x-x My guess for 99% of hams the current SDR model is quite adequate as folks want to buy or download free sw as new stuff is developed by those technically able to produce it. In that sense the current crop of Flex and Elecraft SDR's are fine. SDR is a new acronym for folks to figure out and understand - this discussion is good for that! Ed - KL7UW x-x-x-x-x-x-x 73 de n1dam 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: [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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In reply to this post by Bruce Beford-2
Let me say that I calculate path losses the same way I did as an engineer at the phone co when calculating the losses in fiber optic systems - the path loss includes all losses between the TX and RX. This is the path the signal takes, hence this is the path loss. We must deliver a certain amount of energy to the RX. If it is in the path and it has loss, it becomes part of the path loss. As best I can tell this is the same approach employed in VOACAP. There they call it system loss instead of path loss. But I believe it is the same quantity. If you chose to define it differently that is fine. And keep in mind that this does not include the gain of an amp or a beam. If you put those into the mix the RX noise level increases by several dB. You can call the level by whatever term you prefer. -27 dBm, 2 microwatts, S9+45. They are all the same. S9 is a reference point, so many dBm. TX/RX makes no difference. It is a signal level we are talking about. A level of S9 is something many hams are familiar with. They can relate to S9+45 better than they can relate to 2 uW. This is just like SWR = 2, return loss = 9.5 dB, voltage reflection coefficient = .33, power reflection coefficient = .11, they are all different ways of expressing the same thing. But far more hams know what SWR = 2 means than know what RL = 9.5 dB means. And, yes, the wideband noise emitted by any of the Flex TX is excessive. 73 de dave ab9ca/4 On 12/31/13 5:50 PM, Bruce Beford wrote: > Dave, I agree with your math, except... > > Having a noise level of -27dBm delivered by the transmitter to the antenna > system, does not mean the antenna has 100% radiation efficiency, yes? > > So -27dBm is 2 microwatts in transmitted noise to the antenna system, at > this particular spacing, in a 500Hz bandwidth. > > You must make some allowances for not only path loss, but antenna efficiency > on each end, yes? > > As I said, I am not trying to defend these performance (or lack thereof) > claims. I just disagreed with the statement that the "Flex is transmitting > wideband S9+45 noise" > > "S9+45dB" is a receive measurement, not a transmitter measurement. The Flex > is sending 2 microwatts to the antenna at the frequency in question. > Admittedly, that's too much, in many situations. > > Peace, > Bruce N1RX > > > > > ______________________________________________________________ > 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 Fred Smith-2
I have the following setup:
K3 (with two receivers) P3 with SVGA Steppir 3 element Yagi External monitor attached to P3 I am having problems with the P3 SVGA being sluggish and periodically locking up. Sometimes the external monitor locks up, sometimes both. I can usually get it running by turning the P3 off and on. This happens fairly frequently and can be quite annoying. The impression is the P3 SVGA is overloaded and can't keep up. The software is all up to date. Everything else seems to be working just fine. Any help would be appreciated. ______________________________________________________________ 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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I have this happen occasionally, but only when I am transmitting with the
KPA500. In RX and barefoot, it's solid. I'm going to try some additional snap-on ferrite chokes on the lines, etc. - 73 de Mike, K6MKF, W6NAG, Secretary - NCDXC, IDXG, RRC #933, K3-P3-KPA500-KAT500 Addict, Maui -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of George Thornton Sent: Friday, January 03, 2014 8:57 AM To: [hidden email] Subject: Re: [Elecraft] P3 svga hangs I have the following setup: K3 (with two receivers) P3 with SVGA Steppir 3 element Yagi External monitor attached to P3 I am having problems with the P3 SVGA being sluggish and periodically locking up. Sometimes the external monitor locks up, sometimes both. I can usually get it running by turning the P3 off and on. This happens fairly frequently and can be quite annoying. The impression is the P3 SVGA is overloaded and can't keep up. The software is all up to date. Everything else seems to be working just fine. Any help would be appreciated. ______________________________________________________________ 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 George Thornton
Mine used to hang occasionally when I was running 1920 x 1080
resolution. It hasn't happened since I switched to 1440 x 900. Dave Hachadorian, K6LL Yuma, AZ -----Original Message----- From: George Thornton Sent: Friday, January 3, 2014 9:57 AM To: [hidden email] Subject: Re: [Elecraft] P3 svga hangs I have the following setup: K3 (with two receivers) P3 with SVGA Steppir 3 element Yagi External monitor attached to P3 I am having problems with the P3 SVGA being sluggish and periodically locking up. Sometimes the external monitor locks up, sometimes both. I can usually get it running by turning the P3 off and on. This happens fairly frequently and can be quite annoying. The impression is the P3 SVGA is overloaded and can't keep up. The software is all up to date. Everything else seems to be working just fine. Any help would be appreciated. ______________________________________________________________ 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 George Thornton
Hi, George. I reported a similar problem here on the reflector in early December: ----- I am using a P3 with the SVGA option. It is connected to a K3. I find that frequently after transmitting -- particularly calling a DX station in a split-frequency pileup -- the P3 display comes back sluggish or almost frozen for up to 20 seconds or so. Then it returns to providing real-time information. It's almost like the P3 is suffering from data overload, finally processes it, and gets back to normal. This is particularly annoying as one cannot spot where the DX is listening in said pileup because the screen is essentially frozen and does not display stations real-time until it "unfreezes". This happens regardless of mode (CW, SSB or RTTY). In RTTY this "freeze time" also locks up the USB keyboard. The problem does not appear to be RFI related, as I get it regardless of the power output level. ----- This may or may not be your situation. It only seems to occur in fixed-tune mode. Elecraft (Howard and Paul) responded that they were able to duplicate the problem, but I have never heard a resolution other than to use tracking mode instead. As you say, this is very annoying and makes operating RTTY a chore. I've since started using a different rig, in part due to this issue. Larry K5RK -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of George Thornton Sent: Friday, January 03, 2014 10:57 AM To: [hidden email] Subject: Re: [Elecraft] P3 svga hangs I have the following setup: K3 (with two receivers) P3 with SVGA Steppir 3 element Yagi External monitor attached to P3 I am having problems with the P3 SVGA being sluggish and periodically locking up. Sometimes the external monitor locks up, sometimes both. I can usually get it running by turning the P3 off and on. This happens fairly frequently and can be quite annoying. The impression is the P3 SVGA is overloaded and can't keep up. The software is all up to date. Everything else seems to be working just fine. Any help would be appreciated. ______________________________________________________________ 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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