Re: [Flexradio] Question regarding commercial AM broadcasters' carrieraccuracy
One thing that I would say is that getting an accurate calibration down in the broadcast AM band is pretty tough depending on your tools for measurement. Reason being that what you are correcting for (mainly) is error in the 200MHz oscillator. That error gets divided down to whatever frequency you are using to calibrate. So, for example, if you calibrate at 1MHz, an error of 200Hz at the LO (200MHz) would show up as a 1Hz error ( 200Hz / (1MHz / 200MHz) ). This means that you will likely find a wide range of acceptable DDS clock values that are fairly accurate because adjusting the clock doesn't make that much difference around 1MHz. For this reason, it is best to calibrate at a higher frequency. If possible, try calibrating up in the 52MHz range for an optimal frequency calibration as the error isn't divided down nearly so far. Obviously this isn't as trivial as finding a strong signal on WWV, but for those that really want a good calibration, higher frequencies on a signal generator are better. Eric Wachsmann FlexRadio Systems -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] radio.biz] On Behalf Of Mark Amos Sent: Monday, November 06, 2006 12:01 PM To: flexradio@flex-radio.biz Subject: [Flexradio] Question regarding commercial AM broadcasters' carrieraccuracy Folks, I had the oscillator mod applied this past summer, and I've noticed that after zero beating with WWV at 10 Mhz it stays put pretty well. I thought it would be interesting to take a look at the carriers of some broadcasters and see where they're at. I tuned in their nominal frequency in DSB and adjusted the DDS Clock Offset until I got zero beat per the Phase display. Most of these were local (Northwest Ohio) stations. Below are the results I got. Also, I would have thought that they would be much closer to WWV or CHU, but they're pretty much all over the place. However, when I plotted broadcasters nominal frequences (1310 to 1560 KHz) against DDS offset, I saw an apparently periodic pattern(!) This led me to believe that the differences might have something to do with a measurement artifact or DDS inaccuracy or some such. I would have expected these measurements to differ randomly if they were due to frequency misalignment at the broadcasters. As expected WWV, CHU and my bench oscillator all clustered nicely. They were between -2490 and -2575. Any thoughts? Mark KHz Offset to zero beat 1310 -1810 1330 -3210 1340 -2280 1370 -1825 1430 -1605 1450 -1700 1470 -2075 1490 -2375 1520 -2020 1560 -1775 1800 -1370 3330 -2490 7335 -2560 9450 -2580 9625 -2170 9985 -2430 1 -2563 1 -2503 (bench TCXO) 14670 -2570 15000 -2575 ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Question regarding commercial AM broadcasters' carrieraccuracy
Eric, Thanks - that makes sense: the offset needed to be changed by much more to notice a difference down in the BC. Would a better test of the accuracy of broadcast carriers be to calibrate the flexradio at some high frequency and then just look at the difference in measured vs nominal broadcast frequency and plot that? I would have thought that these two techniques would result in similar results, but I'll give it a shot. Also thanks to the other folks that suggested an OCXO and calibration techniques. At this point I really don't have a need for exceptional LO accuracy / stability - I'm just interested in learning more about this. I'm collecting parts for a GPS disciplined oscillator and hope to hook it up to the FlexRadio at some point. (I'll just use it to calibrate the Flex until I get the courage up to actually do the hack...) Mark -Original Message- From: Eric Wachsmann [mailto:[EMAIL PROTECTED] Sent: Monday, November 06, 2006 1:22 PM To: 'Mark Amos'; Subject: RE: [Flexradio] Question regarding commercial AM broadcasters' carrieraccuracy One thing that I would say is that getting an accurate calibration down in the broadcast AM band is pretty tough depending on your tools for measurement. Reason being that what you are correcting for (mainly) is error in the 200MHz oscillator. That error gets divided down to whatever frequency you are using to calibrate. So, for example, if you calibrate at 1MHz, an error of 200Hz at the LO (200MHz) would show up as a 1Hz error ( 200Hz / (1MHz / 200MHz) ). This means that you will likely find a wide range of acceptable DDS clock values that are fairly accurate because adjusting the clock doesn't make that much difference around 1MHz. For this reason, it is best to calibrate at a higher frequency. If possible, try calibrating up in the 52MHz range for an optimal frequency calibration as the error isn't divided down nearly so far. Obviously this isn't as trivial as finding a strong signal on WWV, but for those that really want a good calibration, higher frequencies on a signal generator are better. Eric Wachsmann FlexRadio Systems -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] radio.biz] On Behalf Of Mark Amos Sent: Monday, November 06, 2006 12:01 PM To: flexradio@flex-radio.biz Subject: [Flexradio] Question regarding commercial AM broadcasters' carrieraccuracy Folks, I had the oscillator mod applied this past summer, and I've noticed that after zero beating with WWV at 10 Mhz it stays put pretty well. I thought it would be interesting to take a look at the carriers of some broadcasters and see where they're at. I tuned in their nominal frequency in DSB and adjusted the DDS Clock Offset until I got zero beat per the Phase display. Most of these were local (Northwest Ohio) stations. Below are the results I got. Also, I would have thought that they would be much closer to WWV or CHU, but they're pretty much all over the place. However, when I plotted broadcasters nominal frequences (1310 to 1560 KHz) against DDS offset, I saw an apparently periodic pattern(!) This led me to believe that the differences might have something to do with a measurement artifact or DDS inaccuracy or some such. I would have expected these measurements to differ randomly if they were due to frequency misalignment at the broadcasters. As expected WWV, CHU and my bench oscillator all clustered nicely. They were between -2490 and -2575. Any thoughts? Mark KHz Offset to zero beat 1310 -1810 1330 -3210 1340 -2280 1370 -1825 1430 -1605 1450 -1700 1470 -2075 1490 -2375 1520 -2020 1560 -1775 1800 -1370 3330 -2490 7335 -2560 9450 -2580 9625 -2170 9985 -2430 1 -2563 1 -2503 (bench TCXO) 14670 -2570 15000 -2575 ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Question regarding commercial AM broadcasters' carrieraccuracy
That procedure makes more sense to me. It is probably going to come down to what tools you are using to make the final measurement. Our display is only accurate to 11Hz per bin at best (more likely more Hz / pixel on the display). Eric Wachsmann FlexRadio Systems -Original Message- From: Mark Amos [mailto:[EMAIL PROTECTED] Sent: Monday, November 06, 2006 1:42 PM To: 'Eric Wachsmann'; flexradio@flex-radio.biz Subject: RE: [Flexradio] Question regarding commercial AM broadcasters' carrieraccuracy Eric, Thanks - that makes sense: the offset needed to be changed by much more to notice a difference down in the BC. Would a better test of the accuracy of broadcast carriers be to calibrate the flexradio at some high frequency and then just look at the difference in measured vs nominal broadcast frequency and plot that? I would have thought that these two techniques would result in similar results, but I'll give it a shot. Also thanks to the other folks that suggested an OCXO and calibration techniques. At this point I really don't have a need for exceptional LO accuracy / stability - I'm just interested in learning more about this. I'm collecting parts for a GPS disciplined oscillator and hope to hook it up to the FlexRadio at some point. (I'll just use it to calibrate the Flex until I get the courage up to actually do the hack...) Mark -Original Message- From: Eric Wachsmann [mailto:[EMAIL PROTECTED] Sent: Monday, November 06, 2006 1:22 PM To: 'Mark Amos'; Subject: RE: [Flexradio] Question regarding commercial AM broadcasters' carrieraccuracy One thing that I would say is that getting an accurate calibration down in the broadcast AM band is pretty tough depending on your tools for measurement. Reason being that what you are correcting for (mainly) is error in the 200MHz oscillator. That error gets divided down to whatever frequency you are using to calibrate. So, for example, if you calibrate at 1MHz, an error of 200Hz at the LO (200MHz) would show up as a 1Hz error ( 200Hz / (1MHz / 200MHz) ). This means that you will likely find a wide range of acceptable DDS clock values that are fairly accurate because adjusting the clock doesn't make that much difference around 1MHz. For this reason, it is best to calibrate at a higher frequency. If possible, try calibrating up in the 52MHz range for an optimal frequency calibration as the error isn't divided down nearly so far. Obviously this isn't as trivial as finding a strong signal on WWV, but for those that really want a good calibration, higher frequencies on a signal generator are better. Eric Wachsmann FlexRadio Systems -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] radio.biz] On Behalf Of Mark Amos Sent: Monday, November 06, 2006 12:01 PM To: flexradio@flex-radio.biz Subject: [Flexradio] Question regarding commercial AM broadcasters' carrieraccuracy Folks, I had the oscillator mod applied this past summer, and I've noticed that after zero beating with WWV at 10 Mhz it stays put pretty well. I thought it would be interesting to take a look at the carriers of some broadcasters and see where they're at. I tuned in their nominal frequency in DSB and adjusted the DDS Clock Offset until I got zero beat per the Phase display. Most of these were local (Northwest Ohio) stations. Below are the results I got. Also, I would have thought that they would be much closer to WWV or CHU, but they're pretty much all over the place. However, when I plotted broadcasters nominal frequences (1310 to 1560 KHz) against DDS offset, I saw an apparently periodic pattern(!) This led me to believe that the differences might have something to do with a measurement artifact or DDS inaccuracy or some such. I would have expected these measurements to differ randomly if they were due to frequency misalignment at the broadcasters. As expected WWV, CHU and my bench oscillator all clustered nicely. They were between -2490 and -2575. Any thoughts? Mark KHz Offset to zero beat 1310-1810 1330-3210 1340-2280 1370-1825 1430-1605 1450-1700 1470-2075 1490-2375 1520-2020 1560-1775 1800-1370 3330-2490 7335-2560 9450-2580 9625-2170 9985-2430 1 -2563 1 -2503 (bench TCXO) 14670 -2570 15000 -2575 ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz
[Flexradio] Frequency calibration, measurement of unknowns with SDR1000Re: Question regarding commercial AM broadcasters' carrieraccuracy
At 01:30 PM 11/6/2006, Eric Wachsmann wrote: That procedure makes more sense to me. It is probably going to come down to what tools you are using to make the final measurement. Our display is only accurate to 11Hz per bin at best (more likely more Hz / pixel on the display). Single point cals may not be adequate since there's two factors that affect the scale position of a signal on the display: the sample rate of the sound card and the DDS frequency. The preferred approach would be to feed in two signals separated by, say, 5-6 kHz, all derived from some reference. For instance, if you had a calibrator at 15 MHz, and modulated that with a sine (or square wave) at 3 kHz, where the 3 kHz is from dividing the 15 MHz down by 5000 (obviously, a divisor like 4096 might be more convenient), you'd get a set of well controlled sidebands. Then, by measuring the spacing of the sidebands you can calibrate the sample rate of the sound card, and by measuring the displacement of the center frequency you can calibrate the DDS reference oscillator. For AM broadcast stations, something like a 10 MHz oscillator divided down to make a 25 kHz marker generator might work well. You'd be able to capture the BC station of interest, as well as more than one marker, in the same recording bandwidth. James Lux, P.E. Spacecraft Radio Frequency Subsystems Group Flight Communications Systems Section Jet Propulsion Laboratory, Mail Stop 161-213 4800 Oak Grove Drive Pasadena CA 91109 tel: (818)354-2075 fax: (818)393-6875 ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
[Flexradio] Was this answered?
Question: Is there going to be a SDR hardware offering for the amateur radio market that is in quality and features, in between the SDR-1000 and the SDR-X ? If so what would be the major differences in the hardware from the SDR-1000 and what is the estimated price range? 73 Ross K9COX ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
[Flexradio] Schematics
Where are the schematics? My esteemed and Flex-famous friend Jeff, K6JCA, has a nice set of schematics. Now that I've toasted something in my Flex I'd like to get a set to in the hopes that I can do some untoasting here instead of sending the box back to Texas. But I can't seem to locate the schematics on the web. Where are they? What's toasted you ask? Something in the X2 driver. I built my own UCB (why did I do this?) and in the process of trying it out I got something wrong. Now pin 7, PTT out, goes from O.L. to 5M on transmit, hardly sufficient. I enabled pin 1 on transmit thinking dang I've toasted the driver for pin 7 I'll use pin 1 as a substibute. Guess what it does once enabled. Yes, O.L. to 5M on PTT. How interesting. Jon, K6JEK ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Schematics
Jon, I'll contact you off-list with the information. Eric Wachsmann FlexRadio Systems -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] radio.biz] On Behalf Of K6JEK Sent: Monday, November 06, 2006 6:10 PM To: 'FlexList' Subject: [Flexradio] Schematics Where are the schematics? My esteemed and Flex-famous friend Jeff, K6JCA, has a nice set of schematics. Now that I've toasted something in my Flex I'd like to get a set to in the hopes that I can do some untoasting here instead of sending the box back to Texas. But I can't seem to locate the schematics on the web. Where are they? What's toasted you ask? Something in the X2 driver. I built my own UCB (why did I do this?) and in the process of trying it out I got something wrong. Now pin 7, PTT out, goes from O.L. to 5M on transmit, hardly sufficient. I enabled pin 1 on transmit thinking dang I've toasted the driver for pin 7 I'll use pin 1 as a substibute. Guess what it does once enabled. Yes, O.L. to 5M on PTT. How interesting. Jon, K6JEK ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
[Flexradio] is someone going to write up minutes from the town hall mtg?
I listened after the fact in my car this morning on the way to work. It would be nice if someone would summarize the salient facts, or, even, just give a at time mm:ss, the following was discussed. Jim, W6RMK ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] SAM Lock
On 11/3/06, KA5MIR [EMAIL PROTECTED] wrote: Sorry to keep bringing this up, but... In the current console, SAM mode doesn't work well. There is no hang time after a lock and with no signal or weak signals, you can hear the receive frequency fluttering constantly. There is also no user adjustment for lock range or timing. I don't know if the folks who use SSB exclusively realize how important a feature SAM Lock is to us who SWL or enjoy AM. It is a GREAT feature. All the modern quality receivers have this capability. I would like to request that the SAM Lock feature in Jeff/K6JCA's console be merged into the current version. The code is done. His implementation WORKS WELL! Why try to reinvent what Jeff has so graciously offered to us for free? Thanks to the code maintainers for considering this request. Jeff/KA5MIR I would also like to see Jeff's/JCA code implemeted for the SAM lock. His lock settings could simply be part of the mode specific controls on the console. Brian/W5AMI ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
[Flexradio] Forward Power Meter
I have no power output indicated on the forward power meter during transmit on the PowerSDR console while in CW and Tun. The correct amount of power out is occurring and has been verified on an external in-line power meter. The forward power meter on the PowerSDR console works fine in all other modes and indicates power out correctly (USB, LSB, AM, FM, etc) it just doesn't indicate any power out in CW or tune and just reads 0. The same thing is occurring on two separate SDR-1000's, two separate computers and does the same thing whether it is 1.6.2 or Beta 1.6.3. What am I not doing right? Any suggestions would be greatly appreciated. 73 Joel W5ZN ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Schematics
Eric, I miss the schematics and all ECOs. Why not put them downloadable as they were earlier? Actually, the schematic diagrams should be updated to reflect the present situation with all the ECOs included. At the same time the resolution should be increased so that the component values and finer details of the circuitry would have better legibility. 73, Ahti OH2RZ On 07/11/06, Eric Wachsmann [EMAIL PROTECTED] wrote: Jon, I'll contact you off-list with the information. Eric Wachsmann FlexRadio Systems -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] radio.biz] On Behalf Of K6JEK Sent: Monday, November 06, 2006 6:10 PM To: 'FlexList' Subject: [Flexradio] Schematics Where are the schematics? My esteemed and Flex-famous friend Jeff, K6JCA, has a nice set of schematics. Now that I've toasted something in my Flex I'd like to get a set to in the hopes that I can do some untoasting here instead of sending the box back to Texas. But I can't seem to locate the schematics on the web. Where are they? What's toasted you ask? Something in the X2 driver. I built my own UCB (why did I do this?) and in the process of trying it out I got something wrong. Now pin 7, PTT out, goes from O.L. to 5M on transmit, hardly sufficient. I enabled pin 1 on transmit thinking dang I've toasted the driver for pin 7 I'll use pin 1 as a substibute. Guess what it does once enabled. Yes, O.L. to 5M on PTT. How interesting. Jon, K6JEK ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
