[Flexradio] 5000A with V/U, RX2, ATU on eBay
I ended up listing my fully loaded 5000A on eBay: http://www.ebay.com/itm/190833186647 In case the link doesn't work, it's item number 190833186647 73, John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/
[Flexradio] V/U antenna configuration?
Can the 5000 V/U be configured to put both 2m and 70cm on a single antenna connector, or are you required to use separate connectors for each band? Thanks, John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/
Re: [Flexradio] V/U antenna configuration?
Thanks, Alan. I don't have my 5K running at the moment (no antennas installed yet) but am planning for a portable operation and wanted to figure out antenna cabling. 73, John On Apr 26, 2012, at 8:09 PM, Alan NV8A n...@charter.net wrote: On 04/26/12 06:17 pm, John Ackermann N8UR wrote: Can the 5000 V/U be configured to put both 2m and 70cm on a single antenna connector, or are you required to use separate connectors for each band? There are separate connectors. AFAIK, there is no way of combining the signals onto one. I use a duplexer. 73 Alan NV8A ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/
Re: [Flexradio] [FlexRadio] 3-pin xlr microphone flex-5000
Alan NV8A wrote: D-Star is not proprietary to Icom. It's my understanding that it was developed as a cooperative venture between JARL, the manufacturers, and the Japanese government. I think that Kenwood sells D-Star rigs in Japan but for whatever reason doesn't in the USA. Not to go too far down a rat hole, but while you're correct that the D-Star protocol at the high level is not proprietary, the digital voice codec (AMBE) that D-Star uses is patent-encumbered and available only as a hardware chip or through a very expensive software license. That means, for example, that until the patent expires no one can write an SDR program to let your Flex 5000 with V/U module talk through a D-Star repeater. You'll need to buy the DVDongle or equivalent hardware to provide the digital voice function. Alternatively, you can pay more than $100K (according to educated guesses) for a license to implement AMBE in a closed-source program; a license for an open source version is simply unobtainable. So, for practical purposes, D-Star digital voice today *is* a proprietary system, though the proprietary party isn't Icom, but the patent holder, Digital Voice Systems, Inc. The way to solve the problem is to use a non-patented CODEC, but good ones for narrow bandwidth applications are hard to find. As someone earlier noted, progress is being made in that area, though.* John * Another wrinkle is that a new CODEC almost by definition won't be compatible with AMBE, so you couldn't drop it into an existing D-Star repeater system without some sort of decode-then-recode process at the repeater, which adds expense and complexity, and is likely to reduce voice quality. ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ Message delivered to arch...@mail-archive.com
Re: [Flexradio] [FlexRadio] 3-pin xlr microphone flex-5000
Larry Rappaport said the following on 12/11/2009 08:09 PM: Well, you guys are ignoring IRLP for some reason. That uses a free codec - FreeVOIP, I think. That is completely free, in use worldwide, uses Linux, etc. What's wrong with that? Basically, it's a free version of D-Star. I like IRLP a lot, but it's a fundamentally different implementation using traditional FM radios and analog repeaters; the digital component only happens on the internet link between repeaters where bandwidth isn't the same issue as it is on RF. D-Star is digital all the way through, which allows some interesting things that you can't do with IRLP such as automatic routing and selective calling. (And I'm sure other things as well; I'm not a D-Star expert. I'm sure others can do a much better job explaining its uses.) John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ Message delivered to arch...@mail-archive.com
[Flexradio] VHF/UHF capability matrix?
I haven't been able to find anything that describes the mode/band operation and antenna selection matrix for the 5000 with the VHF/UHF upgrade installed. In other words, what bands are available on what rear panel connectors, and what combination of HF/6M/VHF/UHF can operate simultaneously? (for extra credit, add how RX2 fits into the mix :-) ) Is that info available somewhere, and if not, can it be? Thanks, John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ Message delivered to arch...@mail-archive.com
Re: [Flexradio] Frequecy Off?
I've used the F5K with an external reference and can verify that it works; you can see WWV's carrier jump when you plug and unplug the external reference. However, perhaps Tim could verify something for the time-nuts amongst us: is the clock for the ADC locked to the same reference as the DDSs, or is it free running? If a free-running crystal feeds the ADC/DAC clocks, there is going to be a frequency error due to that, even if an external reference is used. It's likely to be small(1) and it will not scale with frequency(2). (And just to answer a question that's likely to be asked, the crystal in the PC does *not* contribute any error since the PC isn't doing any analog processing.) John (1) Assuming the ADC/DAC are configured like a typical sound card, the clock crystal is running at something between 10 and 30 MHz, and is effectively divided down to the sample rate by the ADC/DAC chips. That division both reduces frequency offset and drift, and improves phase noise. The couple of Delta 44 cards Ive looked at had a clocking error of less than 1 Hertz, and were quite stable when the computer they were housed in was at a stable operating temperature. (2) Since the ADC/DAC are at baseband, the clock doesn't go through any multiplication related to the operating frequency. Any offset is a simple additive error that applies equally at all RF frequencies. Mark Whatley wrote: I was going to ask a question here today and was surprised to find that it was answered (I think) before I asked it! You guys are good! I was going to ask if I connect my Z3801's 10 MHz output to my F5K will the Flex inherit the same accuracy as the standard? I think the Stu might have answered that in his post but thought I would ask anyway. Seems like I have seen other radios that allow external references but they also have some oscillator along the way that is not locked to the reference - like a BFO oscillator - which spoils the overall accuracy. ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ Message delivered to arch...@mail-archive.com
[Flexradio] Using SDR-1000 amplifier stand-alone?
I am contemplating what to do with my SDR-1K and thinking it might make sense to revert it to a QRP unit, pulling the amplifier and tuner out for use with other QRP rigs (like my HPSDR stack). I know there is some interface cabling between the PIO board and the amplifier. Is that an insurmountable issue in using the amp and tuner alone? If anyone has made this work, I'd like to hear about it. Thanks! John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] [FlexRadio] VAC with Vista X64
Lux, James P wrote: Being able to buy it conveniently is even different. -- you call microsoft Oh you want to buy XP for your system. Sure we still support that for people needing to keep their XP machines on the factory floor working. You'll need to talk to one of our Microsoft Industrial Embedded partners. We've got two in North America, would you like the one in California, or the one in Georgia? -- you call the rep in California Good afternoon, ACME Process Controls, may I help you? -I'd like to get a copy of Windows XP Oh, you'll need to talk to our small sales department, but he's out of the office right now, may I take a message? -three days later, he calls back and leaves a message Hi, this is Bob, and I'm your rep for Microsoft Industrial Embedded. How many controllers are you retrofitting? - You finally get a hold of Bob, and tell him you need one copy of XP No problem. Let's see now, I assume your hardware is on the Microsoft Approved Hardware List? Can you just read off the model number and validation stickeroh, it's not on the list and you don't have a sticker? You need to talk to OEM sales, then. --- A week later, you finally talk to OEM sales. Sure, we'll set you up. We've got very attractive licensing terms. You can get 100 copies for only $10,000, plus an annual support fee of $10/year for each copy that's installed Just as a data point, I bought a new Lenovo Thinkpad T500 laptop a couple of months ago, and as part of the on-line order process was able to specify XP Pro instead of Vista just by checking a box. No extra charge. John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
[Flexradio] SDR-1000 for sale
I posted this shortly before Christmas, but had no takers at the price I asked then, so am giving it another try. Rather than posting a price, please contact me off-list at j...@febo.com and we'll see if we can make a deal. FOR SALE: SDR-1000 with 100 watt amplifier, ATU, and DEMI 2M transverter. Also includes parallel to USB converter cable and SDR-LPF/CBL audio cable. Not sure if this is the serial number or not, but a label on the bottom says ASM-0437004. Returned to Flex in July 2007 for checkout, installation of transverter, and upgrade with all ECOs (including update to 8 pin mic connector). I'll provide the service report (dated 2 July 2007) showing performance verification at that time. Radio is in as-new condition with very little use since the 2007 service. Currently configured for external frequency reference; I will include the original 200 MHz oscillator with the unit, and can reinstall it and reconfigure the unit for internal frequency reference if desired. Please contact me off-list if you're interested. Thanks! John N8UR ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
[Flexradio] Record both RX1 and RX2 to WAV file?
I may not have been searching in the right way, but I couldn't find out if it's possible to record both RX1 and RX2 to a WAV file simultaneously, preferably one RX in each (left/right) channel. Can that be done? Thanks, John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
[Flexradio] SDR-1000/PA/ATU/XVTR for sale
Hi -- Too many radios, too little time... SDR-1000 in as-new condition with 100 watt amp, internal antenna tuner, internal DEMI transverter, USB/Parallel adapter cable. Serviced by Flex in July 2007 with all ECOs and updated 8 pin mic connector installed; test report included with the radio. Virtually zero use since then. Currently configured for external 10 MHz reference; I can change that back for the buyer if desired. Asking $1200 plus shipping (from Dayton, OH) for the package. I also have an unassembled UCB kit available separately (see my other posting). 73, John N8UR ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
[Flexradio] Unassembled UCB kit for sale
I discovered that I have an unassembled UCB complete kit (including relays) that I won't need. This is Tony Parks'/Phil Theis' original version, not the later Poor Man's UCB. I paid $99 plus shipping for it in early 2007. Best offer over $50 in the next 72 hours gets it. Thanks! 73, John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
[Flexradio] Small LCD monitor?
I think this has been discussed here before, but I can't find the references... I'd like to find a 12-14 inch, 1024x768 LCD monitor to fit under the shelf on my desk and to display PowerSDR in a dual-monitor configuration with a larger monitor running other applications. Small monitors seem hard to find, except in expensive configurations for industrial use. Anyone know of something that's pre-packaged (i.e., not a notebook display that would require a bunch of integration) for a reasonable price? Thanks, John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Small LCD monitor?
Yup, that's the problem! ($350 each, to spare the rest of you looking it up.) John Tim Ellison wrote: John, I googled on your text string 12-14 inch, 1024x768 LCD monitor and found: http://www.nextag.com/Miracle-Business-Inc-LT12B-88114962/prices-html?nxtg=13b70a1c0533-1050D7697472EE56 http://www.esis.com.au/LCD-Monitors/LCD-Monitors.htm#LCD_12_14 They are rare creatures and [Small != cheap] -Tim -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of John Ackermann N8UR Sent: Thursday, October 02, 2008 11:32 AM To: flexradio@flex-radio.biz Subject: [Flexradio] Small LCD monitor? I think this has been discussed here before, but I can't find the references... I'd like to find a 12-14 inch, 1024x768 LCD monitor to fit under the shelf on my desk and to display PowerSDR in a dual-monitor configuration with a larger monitor running other applications. Small monitors seem hard to find, except in expensive configurations for industrial use. Anyone know of something that's pre-packaged (i.e., not a notebook display that would require a bunch of integration) for a reasonable price? Thanks, John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/ ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
[Flexradio] RX2 -- Waterfall problem still in 1.14.0?
I think I reported this earlier, but didn't get feedback as to whether anyone else has seen this, so I'll ask again, now that I have 1.14.0 and am still seeing the same thing... If I select the waterfall display for both RX1 and RX2, it appears that the RX2 waterfall is simply a duplicate of the RX1. If RX1 is using another mode (e.g., panadapter), the RX2 waterfall seems to be more-or-less correct (there is a fixed blue line about 10.6 kHz below the tuned frequency that seems wrong). But as soon as I switch RX1 to waterfall, the RX2 waterfall simply copies the RX1 display. So, is it just me, or is there a bug? BTW -- I'm having great fun tuning around with RX1 and RX2 in a diversity mode, using my vertical on one RX and horizontal wire with the other. It's very interesting to see what paths work best on one antenna versus the other, in real time. John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] K6JCA display improvements
Eric, since you're asking for input... I already filed an enhancement suggestion for this, but two thoughts about antenna selection: 1. Since you use screen real estate to show the selected antennas (on the left, about 1/3 up from the bottom), why not turn those into drop boxes so you can do at least basic antenna selection without having to go to the top menu bar? 2. Ability to name antennas would be nice. I know the screen real estate is limited, but a 4 character abbreviation would be enough to be useful. Thanks, John Eric Wachsmann said the following on 08/01/2008 03:19 PM: Excellent questions. The split waterfall/panadapter feature is very nice. We appreciate Jeff taking the initiative to continue to innovate useful features like this. Unfortunately, about the same time, we were incorporating RX2 support. The conflicts between what were added to support RX2 and the existing Pan/Waterfall code were unfortunately too far beyond reconciling to get into the official release easily. This feature is definitely slated for 1.13.x versions. Input is welcome on this ... especially with regard to how to handle RX2 and the split display options. As for the appearance controls, we would like to find a way to handle the changes in a more automated fashion so that we don't have to manually change those functions each time controls are added/removed. That maintenance really adds up over time. Eric Wachsmann FlexRadio Systems -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jesse N4BFD Sent: Friday, August 01, 2008 1:12 PM To: flexradio@flex-radio.biz Subject: [Flexradio] K6JCA display improvements Hello, I was just curious as to why the added features of the K6JCA SVN release such as the split waterfall/panadapter, and the ability to change the coloring of the overall GUI have not been added to the trunk? It has been out for many months now, and I prefer to use this release due to it being easier on the eyes after long hours of use after adjusting the appearence to something that I like. However, many other features of course have been added to the trunk, so I am starting to miss out on somethings. N4BFD ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/ ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] New Model from FlexRadio?
*That* is impressive! John PS -- I went to the Round the Horne Revisited stage show a few years ago. Another great British radio show. Alan NV8A said the following on 07/26/2008 10:20 PM: Probably I can do you one better: I attended one of their recording sessions back in the 1950s. 73 Alan NV8A On 07/26/08 07:55 pm Frank Brickle wrote: Sapristi niakos! Found out! Precisely -- and yours also, John, you silly, twisted boy. 73 Frank AB2KT On Sat, Jul 26, 2008 at 4:31 PM, John Ackermann N8UR [EMAIL PROTECTED] wrote: Not surprising -- I recall Frank's familiarity with The Highly-Esteemed Goon Show! John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
[Flexradio] RX2 Waterfall problem?
I just installed 1.12.1 and continue to see a bug I noticed earlier, but didn't have a chance to question then... When I am using RX1 and RX2, and set both displays to waterfall, it appears that the RX2 waterfall is simply a copy of the RX1 display, though the legend of the lower waterfall matches the RX2 frequency. If RX1 is set to panadapter, and RX2 is set to waterfall, there is no RX2 display at all. So, it appears that the only functional display for RX2 is panadapter. Is this a known problem? 73, John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
[Flexradio] Audio mixer/amp recommendation?
I'm thinking that instead of two separate sets of amplified speakers to support the Flex 5000 audio out, as well as the computer's audio out, it might be more efficient to use a single box that would be a mixer and amplifier to drive a single set of unamplified speakers. Has anyone done something like this? Any recommendations on an appropriate mixer/amp? Thanks, John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Audio mixer/amp recommendation?
Those are an interesting idea, Mike. Thanks! Re the ferrites -- I take it you had some RF issues. Were you able to calm things down? John Mike Schelly said the following on 07/26/2008 03:40 PM: A pair of Behringer MS20 or 40's will accommodate two line inputs with separate volume levels, very nice sound. Some shacks may require a few ferrites ;-) Mike K4EAR -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of John Ackermann N8UR Sent: Saturday, July 26, 2008 12:59 PM To: Flex Group Subject: [Flexradio] Audio mixer/amp recommendation? I'm thinking that instead of two separate sets of amplified speakers to support the Flex 5000 audio out, as well as the computer's audio out, it might be more efficient to use a single box that would be a mixer and amplifier to drive a single set of unamplified speakers. Has anyone done something like this? Any recommendations on an appropriate mixer/amp? Thanks, John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/ No virus found in this incoming message. Checked by AVG. Version: 7.5.526 / Virus Database: 270.5.6/1574 - Release Date: 7/25/2008 4:27 PM No virus found in this outgoing message. Checked by AVG. Version: 7.5.526 / Virus Database: 270.5.6/1574 - Release Date: 7/25/2008 4:27 PM ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Audio mixer/amp recommendation?
Thanks, Dale. I was hoping to find a single unit rather than a separate mixer and amp setup, but what you describe sure offers flexibility. Thanks for the tip! John Dale Boresz said the following on 07/26/2008 03:54 PM: Hello John, I've been using one of these: http://www.guitarcenter.com/Behringer-EURORACK-Pro-RX1602-Line-Mixer-631243-i1153486.gc (Behringer Eurorack Pro RX1602 Line Mixer) for a couple of years, to route the outputs from several radios (including the FLEX-5000 and SDR-1000), several computers, and a satellite radio, into an audio preamp/power amp which in turn drives a pair of high quality non-amplified speakers. It works great, and provides independent volume, balance, and muting for each of the 8 stereo input channels. 73, Dale WA8SRA John Ackermann N8UR wrote: I'm thinking that instead of two separate sets of amplified speakers to support the Flex 5000 audio out, as well as the computer's audio out, it might be more efficient to use a single box that would be a mixer and amplifier to drive a single set of unamplified speakers. Has anyone done something like this? Any recommendations on an appropriate mixer/amp? Thanks, John ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/ ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] New Model from FlexRadio?
Not surprising -- I recall Frank's familiarity with The Highly-Esteemed Goon Show! John Lee Mushel said the following on 07/26/2008 06:34 PM: Frank, I can't believe it! someone else who uses the term highly-esteemed! My use goes back 40 years to one of my first jobs and the context is usually one of sarcasm. But no matter. Just as long as it doesn't disappear! People who know me know that most of my stuff, even that of Asian origin, is highly-esteemed! I was having a bad day but you've turned it around! 73 Lee K9WRU - Original Message - From: Frank Brickle [EMAIL PROTECTED] To: Tim Ellison (W4TME) [EMAIL PROTECTED] Cc: [EMAIL PROTECTED]; flexradio@flex-radio.biz Sent: Saturday, July 26, 2008 1:32 PM Subject: Re: [Flexradio] New Model from FlexRadio? Tim is exactly right. And anyway, we're out of the closet in admitting that the highly-esteemed new architecture is really just some old architecture applied to a mildly novel problem. Calling the prototype VR the new radio might be just a sliver less pretentious than continuing to call it by a name that implies something profoundly revolutionary :-) 73 Frank AB2KT On Sat, Jul 26, 2008 at 10:34 AM, Tim Ellison (W4TME) [EMAIL PROTECTED]wrote: No new physical radio, per se. When you match the new VR code with the FLEX-5000 and the SDR-1000, you will have new software defined radios that are going to be very different from what you have today with PowerSDR 1.x. That is what was promised to have running for Dayton 09. In the software defined domain of programmers, the hardware is not really the radio, it is just a source and destination for I/Q data streams for some black box to make RF out of. - Tim - FRS Internet Systems Administrator W4TME - Original Message - From: Kirb Nesbitt [EMAIL PROTECTED] To: flexradio@flex-radio.biz Sent: Saturday, July 26, 2008 12:22 PM Subject: [Flexradio] New Model from FlexRadio? New Radio? Please step up and speak into the microphone, sir. :-) Frank, AB2KT said- Sooner than you might think. We are moving very fast now towards an earlier exposure of alpha code for the new radio than we'd previously announced (Dayton next). Kirb - VE6IV ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/ ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/ -- Travelling by airplane in the US is nothing more than mass training of Americans to the requirements of the coming police state. The whole point is to make you learn to acquiesce without question, en masse, to completely absurd directives by dull functionaries wearing uniforms. -- Digby ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/ ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/ ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] Worked FDMDV mode w/ FLEX-5000A...
Mike Naruta wrote:
I once became the IT Manager for a company that used
MAI Basic Four equipment. They used special PROMs in
their terminal and printers that were only available
from MAI Basic Four, even though the equipment was
common Printronix, etc. The PROM in the printers
would repeat back the print line exactly as sent by
the host. If the host didn't get the line back within
a short time, it refused to send out any more print
lines. Imagine trying to send that over stat Muxes.
I got rid of that MAI Basic Four stuff as soon as I
was able to.
Interesting... MAI was a party to one of the key cases in the
development of computer law. They had a provision in their license
agreement that prohibited anyone other than the owner from running the
software. Peak was an independent service company that MAI didn't like.
Since you need to boot the computer to diagnose it, MAI sued Peak for
copyright infringement.
The bad news is that MAI won the lawsuit.
The good news is that the decision, while technically correct, was so
wrong in a practical sense that Congress amended the copyright act soon
after, and now there is an explicit permission to run software as
necessary to service equipment in which that software is installed.
{Warning: that was a brief summary from memory; I may have a detail or
two wrong.]
John
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Re: [Flexradio] TCXO
Frank, the 50 ohm resistor was added for two reasons: first, it provides a termination for the coax that's feed the signal and in theory that minimize jitter due to ringing on the coax, and second, the unloaded P-P voltage from oscillators rated at, say, 6dBm into 50 ohms, is high enough that it could exceed the DDS chip's input rating. By providing a load, the resistor keeps the voltage to a safe level. So, if you have a reference with marginal output, removing the resistor might make it work. You'd lose the theoretical jitter protection, but in most cases that's probably a non-issue in the real world. John Frank Mayer said the following on 11/01/2007 05:24 AM: I just can't seem to find a source for one of these for my SDR-1000. That guy K2ws won't answer my emails for some reason and my search for anyone to sell me just one has been futile. All I get is we need your company information Any way I found a 10mhz TCXO on ebay for 39 bucks that has an output of 1V p-p but has no spec sheet to tell me into what load. I have not received the unit as of yet. I understand from the Flex documentaion that the rig requires from 4dbm to 14dbm output into 50 ohms. It tells you when you install the external TCXO kit to put a 50 ohm resistor across the BNC connector for a load. I'm concerned that the TCXO that I am getting won't have that kind of output into 50 ohms. I wonder if raising that value of that resistor would work ok? Any one have experience with installing one of these? Thanks, Frank WA3JBT -- next part -- An HTML attachment was scrubbed... URL: http://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/attachments/20071101/ca2837f9/attachment.html ___ 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 Knowledge Base: http://kb.flex-radio.com/ 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 Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] anyone attend DCC this weekend?
Hi Jim -- The DCC proceedings (paper version) will be available very shortly -- everyone at the conference got one, and I believe that they will be for sale via TAPR and/or ARRL as soon as logistics allow. More importantly, authors retain the copyright to their papers so they are free to distribute them if they'd like, and we encourage them to make their presentation slides freely available on line. John Jim Lux said the following on 10/01/2007 11:51 AM: At 08:14 AM 10/1/2007, Ken N9VV wrote: If you attended the DCC Conference in CT, please send a short report about how the DCC conference went this weekend. There seems to have been no on-line broadcast of any of the speakers :-( [ ] how were Bob N4HY and Frank's AB2KT sessions? [ ] was it well attended? [ ] what surprises did you hear? [ ] what innovations in digital ham radio did you see? [ ] how soon can we purchase a hard copy of the proceedings? Can someone provide a summary of the new architecture which was going to be revealed by Frank? Based on previous posts by Frank, it won't be published except in the proceedings, several months from now, which aren't online, and aren't free, either.The software may be F/OSS, but the documentation apparently isn't grin. Or, does TAPR allow independent distribution of a conference paper? 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 Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] antenna Smith Chart can this be ad to program ?
Jim Lux wrote: At 07:23 PM 6/28/2007, Larry Phipps wrote: My software is free, but not open source. And that appears to be the case for most (if not all) low cost VNA solutions. The TAPR VNA (sold by Ten-Tec) software is open source and licensed under the GPL. It's a Windows implementation but there is also a relatively complete Linux port (that could use some volunteer work to turn into a finished product). The software and documentation is available at http://www.tapr.org/software_library.php?dir=/pub/n5eg John ___ 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 Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] antenna Smith Chart can this be ad to program ?
Jim Lux wrote: At 06:40 AM 6/29/2007, John Ackermann N8UR wrote: Jim Lux wrote: At 07:23 PM 6/28/2007, Larry Phipps wrote: My software is free, but not open source. And that appears to be the case for most (if not all) low cost VNA solutions. The TAPR VNA (sold by Ten-Tec) software is open source and licensed under the GPL. It's a Windows implementation but there is also a relatively complete Linux port (that could use some volunteer work to turn into a finished product). Thanks for the pointer. Which Windows environment is it developed in? I tried to load it up in VS2005 C++ and it brought up the conversion utility.. Also, all the cal routines are just 1K stubs with a couple includes. Maybe I'm looking in the wrong place? (VNAR3_HOST_source, both 1.6 and 2.0) The InstrumentCal.cpp and Calibration.cpp both have 2003 dates. Oho.. I see, they're buried in the .h and .res files.. ANd, where is the Linux port? The windows one is awfully tightly coupled between UI and processing (e.g. the actual cal work is attached to click methods for form controls), and before trying to separate them out, maybe someone has already done that. (My own style is to have the click method just invoke a UI independent routine somewhere else, so the numerical heavy lifting isn't tied to the UI) I didn't write the code, so I don't have deep knowledge of the bits and pieces... I know it uses .NET, though. The Linux port may not be uploaded there; I'll check when I have a chance this weekend and if it's not there upload the latest. Unfortunately, the porting project died about 90% of the way through, and it's now a couple of software revs behind. I suppose there's some mailing list around which has all this. I'll have to google for it.. Check https://lists.tapr.org/mailman/listinfo/vna John The software and documentation is available at http://www.tapr.org/software_library.php?dir=/pub/n5eg Not much software documentation there.. just hardware and software installation/use ___ 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 Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] antenna Smith Chart can this be ad to program ?
Jim Lux wrote: At 06:40 AM 6/29/2007, John Ackermann N8UR wrote: Jim Lux wrote: At 07:23 PM 6/28/2007, Larry Phipps wrote: My software is free, but not open source. And that appears to be the case for most (if not all) low cost VNA solutions. The TAPR VNA (sold by Ten-Tec) software is open source and licensed under the GPL. It's a Windows implementation but there is also a relatively complete Linux port (that could use some volunteer work to turn into a finished product). I assume the free VNA bounty for a Linux version offered back in 2004 hasn't been collected grin Well, it got close enough to be collected -- but it didn't quite get there. We had a working Linux system, but it never got sync'd with the latest version of the Windows code, and there had been some significant changes to sync. I would love someone to pick up the challenge, and there is possibly a sucker, I mean a glorious volunteer, in the wings that I'm working to convince. John ___ 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 Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] [OT] LNA VHF preamps
Tim Ellison said the following on 06/16/2007 04:48 PM: One mfg. claims that the new very low noise dual gate MOS FETs have a better noise figure than the GaAs FETs. I have always heard that the GaAs FETs were the way to go for the best noise figure, so I am confused from the marketing hype. I am looking to get a non-mast mounted preamp for 6 meters. I have a few transceivers that cover 6 meters, but are not the best for weak signal work and need a little help. This could be a receive only device, as that would be it's initial function, but I am not excluding mast mounted ones either. If anyone want to make a recommendation for a particular mfg. or kit, that would be appreciated too. Hi Tim -- Remember that the noise figure of the amp only matters if it's higher than the background noise. So, at 6M where other noise is still significant, you don't need to strive for a 1dB noise figure (even though it's pretty easy to obtain). Similarly, mast mounting doesn't gain you much unless the feedline is very long, unlike at higher frequencies where getting the gain ahead of the coax loss becomes very important. For what it's worth, I've always liked Advanced Receiver Research (www.advancedreceiver.com) preamps. They have a wide range available. John ___ 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 Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
[Flexradio] Another SDR-1000 Phase Noise Measurement
A while ago I did some testing on the SDR-1000 to see whether an external 10 MHz reference oscillator gave worse phase noise performance than the standard 200 MHz oscillator. Then, John, K20X, did some excellent work (see http://www.exothink.com/SDR/SDRPN/index.htm) I've now done some follow-up measurements that build on John's work. Where he measured the noise of the DDS system directly, this time I measured the noise at the transceiver output so that the entire system -- including sound card (a Delta 44) -- was measured. I measured the SDR-1000 when driven by the standard internal oscillator, a fairly noisy Marconi signal generator, an extremely quiet Wenzel Ultra Low Noise oscillator, and an HP Z3801A GPS disciplined oscillator. I also measured a couple of other HF rigs that I had handy to get some idea of how the SDR1000 compared to other transceivers. The results are at http://www.febo.com/pages/hf_phase_noise/index.html I haven't done a lot of deep analysis yet, but here are a few observations: 1. The SDR-1000 with standard oscillator performs about the same as the other HF rigs I tested; it was a bit worse than the other modern rigs below 10 Hz offset, quite a bit better than them between 10 Hz and 10kHz, and somewhat worse at distant offsets. 2. The SDR-1000 has many spurs in the range of about 60Hz to 10kHz offset. I suspect these come from the PC-mounted sound card. They are all at least 60dB down from the carrier, so most likely wouldn't be noticed on the air. Using an external sound card like the Edirol would probably reduce computer-generated spurs, and I'll bet the new SDR-5000 will be much better in this regard because the analog stuff is all inside the box. 3. The results with various 10MHz reference oscillators compared to the standard 200 MHz oscillator were surprising, but make sense if the DDS chip incorporates a PLL: (a) at close offsets -- say, 1 to 10 Hz -- a good external reference shows better phase noise than the internal reference. (b) at mid offsets -- say, 100 Hz to 10 kHz -- there's not much difference between any decent oscillator and the internal reference (the Marconi generator is much worse, but that's why I included it!). (c) at distant offsets -- beyond 10kHz -- two things happen: first, the external references -- even the Marconi -- are just about the same, and second, the internal reference is almost 10dB better at 30 kHz. The fact that all the external references converge indicates that we're seeing the loop filter bandwidth of the PLL that the DDS chip uses to multiply the external reference. The internal 200 MHz crystal oscillator doesn't use this PLL, so it can provide better performance. But... there is something going on from about 30 kHz that causes the noise to increase, no matter what the reference. At 100 kHz, the internal reference has only a couple of dB advantage over any of the external references. Unfortunately, my measurement system only looks out to 100 kHz, so I can't tell what happens further away. I see somewhat similar results on some of K2OX's DDS measurements; his measurements indicate that the noise starts going down again at perhaps 300 kHz offset. 73, John ___ 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 Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Reference Oscillator
To follow up my earlier post, a byproduct of the phase noise measurements I did was frequency stability during the 5 minute transmission period. Those results are at http://www.febo.com/pages/hf_phase_noise/freq.html . Note that my internal oscillator does NOT have the new thermistor ECO applied, so rigs with that change might do better. On the other hand, the rig had been running for 24 hours in a stable environment before the test began. 73, John Phil LaMarche said the following on 06/02/2007 12:39 PM: Asking for an opinion. Instead of using a OCXO, just leave the SDR1K powered up 24/7. Isn't the stability just as good? OR, is even tighter better? Phil Philip LaMarche LaMarche Enterprises, Inc. www.instantgourmetspices.com www.W9DVM.com 727-944-3226 800-395-7795 pin 02 FAX 727-937-8834 NASFT # 30210 W9DVM -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Neal Campbell K3NC Sent: Saturday, June 02, 2007 12:26 PM To: Ken Cc: FlexRadio@flex-radio.biz Subject: Re: [Flexradio] Reference Oscillator I put one of Alan's boards in my SDR1K and can vouch its amazing! Neal Campbell K3NC [EMAIL PROTECTED] telnet to our DX Spotting clusters at: dxc.k3nc.com, ports 12001 and 23 Devoted to Dogs: How to be your dog's best owner Great Dog Book at www.abrohamneal.com On Jun 2, 2007, at 11:30 AM, Ken wrote: One of the most successful is the OCXO mod for the SDR-1000 that Alan K2WS offers as a kit: http://www.k2ws.us/K2WS-OCXO.html he has an installation manual as well: http://www.k2ws.us/Images/K2WS/OXCO-Installation-Guide.pdf de ken n9vv Frank Mayer wrote: Any ideas on a external reference TCXO? Frequency, etc. I have seen some Wenzel units on the internet. Frank WA3JBT ___ 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 Knowledge Base: http://kb.flex-radio.com/ 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 Knowledge Base: http://kb.flex-radio.com/ 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 Knowledge Base: http://kb.flex-radio.com/ 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 Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] Disk-less Flex Radio
RAM is cheap. Use a big RAMdisk and load it, or at least the OS elements that need to be on a R/W filesystem, from USB or Flash media at boot. With a couple of gigs of RAM not being unreasonable today, I'd think you could make this work using a stripped down version of Windows something or other. It's a very different application profile, but embedded systems do this under FreeBSD and Linux all the time, with much smaller RAM footprints (my Soekris net4501 NTP servers boot from a CF image and run with a RAMdisk of less than 32MB). John Larry W8ER wrote: Neal .. I think the point is being missed. USB hard disks. Not flash cards on IDE adapters nor solid state drives on IDE interfaces etc. I can't imagine how they could block booting from any IDE device especially one that emulates an IDE hard drive! --Larry W8ER Neal Campbell K3NC wrote: I do think its possible. If you purchase 2 IDE adapters for flash cards, I believe you should be able to install windows on one and use the other for paging and powersdr. I am not saying I would want to do this, but I cannot see any limitations that would refuse it. My windows folder is 2GB and you can certainly buy bigger flash cards than that. I have had USB disks interfere with WinXP booting before so I know that at least some bios will look there for bootable media. I think if you turn off legacy USB support this will not happen but again, if you use IDE adapters (I paid 3 bucks for mine and it plugs directly into the IDE channel plug on the motherboard). Again, not sure why I would want to do this but I think its possible to do so. Neal Campbell K3NC [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] telnet to our DX Spotting clusters at: dxc.k3nc.com, ports 12001 and 23 Devoted to Dogs: How to be your dog's best owner Great Dog Book at www.abrohamneal.com http://www.abrohamneal.com On May 7, 2007, at 4:47 PM, Larry W8ER wrote: See reply below: k5nwa wrote: Are you running the SDR-1000 software on a company computer? Bad boy! Silly question! No. If you plug in a USB stick then turn on the PC with a XP install disk in the CD ROM you have the option of installing XP on the USB stick. WRONG. It will not install any code into a boot sector. It will err out! Tried it .. been there .. done that. snip ...You can also install Linux in a USB stick. Check out Puppy Linux, it's specifically made to run on a CD or a USB stick and it runs really fast. and what version of PowerSDR do I run under Puppy Linux Cecil? I setup an alternative profile, and turned off everything under the sun that was not needed, I disabled all networking services, all anti-virus, firewall, help, updating, remote access, and any service not needed for use in running the SDR-1000. It went from 50% spiking to 70% to less than 10% with no spikes in utilization. Because it's a separate profile when I boot I have a choice of picking it or the normal profile. XP is also using less that 64MB of RAM while in that configuration. Cecil ... how do you set up such an alternative profile under XP without booting XP from a hard drive first? I thought the idea was to boot the OS and run PowerSDR from a USB memory stick? I contend that you cannot boot an operating system that will run PowerSDR from a USB memory stick. Am I wrong? --Larry W8ER ___ FlexRadio mailing list FlexRadio@flex-radio.biz mailto: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 Knowledge Base: http://kb.flex-radio.com/ 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 Knowledge Base: http://kb.flex-radio.com/ 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 Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] [KB] FLEX-5000 FAQ has been updated
Jim Lux said the following on 04/16/2007 06:23 PM: I'm sure the flex folk have been furiously formulating a response to all of our speculation, little realizing what a firestorm an offhand FAQ might trigger. I just throw some more gasoline on the fire, out of sheer cussedness... reverse engineering the firmware would be illegal in the United States because of the DMCA anti-circumvention rules. I wouldn't leap to that conclusion. The anti-circumvention rules apply only to attempts to work around an effective means of content protection and a couple of court cases have recently held that encryption or locks that aren't related to a copyrightable content stream can't rely on the DMCA.* John * One case involved a Lexmark printer that had a CPU in the toner cartridge; if the CPU didn't handshake with the printer, it wouldn't work. The court held that reverse engineering that interface didn't violate the DMCA. The second case involved a universal garage door opener remote control that reverse engineered a rolling code algorithm. The court there also held that breaing that algorithm didn't violate the DMCA. The main reasoning in both cases is that the mechanisms weren't protecting copyrightable material (like a movie or music) and therefore the DMCA didn't apply. ___ 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 Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] 10 MHz GPS Disciplined Master Oscillator
Jim Lux said the following on 04/11/2007 07:52 PM: If you multiply it up to 200 MHz for the SDR1K, the noise would increase by 20logN, or 26 dB.. That would make the noise at 1kHz out about -124dBc/Hz. The VF161 in the radio already has a floor of about -125 dBc/Hz at 1kHz out, so it's in the same ballpark. With the huge advantage that the frequency is much more stable... We've talked about this in the past, but I don't know if there was ever a definitive answer supplied: Multiplying from 10 up to 200 MHz multiplies the phase noise by 26 dB. However, the DDS output isn't at 200 MHz, but in the HF range. Does phase noise of the DDS output then divide by the ratio of output frequency to clock speed? 73, John ___ 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 Knowledge Base: http://kb.flex-radio.com/ FlexRadio Homepage: http://www.flex-radio.com/
Re: [Flexradio] external OCXO, silly question
The 50 ohm termination does two things: 1. It terminates the coax from the oscillator so you reduce ringing and the possibility of increased jitter that results, and 2. The maximum input voltage that the DDS can accept is fairly low, and an unloaded clock signal can fairly easily exceed that level. The load helps ensure the voltage will be under that limit. John Jean-marc BORD said the following on 03/24/2007 07:02 AM: Hi, Apologize, I do have a rather silly question. I am in the process to connect an external OCXO to the DDS board and saw that the external XO connection kit handle a 50ohm resistor to 'load' the input of the DDS clock. Is it mandatory ? related to the fact that the DDS clock input Z is 50ohm ?. Best regards Jean-marc F1HDI ___ 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 Knowledge Base: http://kb.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 Knowledge Base: http://kb.flex-radio.com/
Re: [Flexradio] Spur on AM
Which transformers did you find with that bandwidth? I bought some of the Stacor ones that had been recommended earlier, and they have signicant roll-off above something like 10kHz. John kd5nwa wrote: You need a transformer with higher bandwidth and better phase response, you can buy some at Mouser for $15 that are flat from 200Hz to 100KHz +- .1 dB, but it's just a transformer, there is no case, connectors or anything. I have some links at home for some commercial isolation transformers that are better than the RS ones but they cost a lot more. At 09:57 AM 1/23/2007, you wrote: I just made a few more measurements using my Delta 44 and some of my test equipment. Adding in the ground-loop isolator to the Line-In path has the following effects: Positive: 1. Noticably reduces the IF hump. 2. Flattens the display (w/o the isolator, I see a bit of rolloff towards the display edges when in 0.5x zoom mode. Negative: 1. Image rejection worsens at the display edges. That is, if a strong signal is in the receive audio passband (I used a -40 dBm signal) and you null its image down to the noise-floor, if you then shift the frequency of the received signal (but not the receiver's VFO-A frequency), you'll see the image begin to reappear. If the signal is moved in frequency such that the image is at the edge of the display (again, in 0.5x zoom mode), it appears to me that the image rejection is about 10 dB worse *with* the line isolator. In other words, it's in the mid to high 30's (of dBs) instead of the mid 40's. (Note, though, that in either case, the image can be nulled down to the noise). I'm not sure that the positives outweigh the negatives, but it raises some questions: 1. Can an isolator be designed, in hardware, to maximize the positives and minimize the negative? 2. Could a filter be designed so that, when it's convolved with the input signal, we maximize image rejection across the whole display, and not just at the frequency for which the image is nulled. That is, can the bowl shaped response to image rejection (when viewed across the entire display) be flattened? If so, how could this be done. (And what's the plan regarding the use of the pulse generator that's in the hardware?) - Jeff, K6JCA Cecil Bayona KD5NWA www.qrpradio.com www.hpsdr.com 'Never argue with an idiot. They drag you down to their level then beat you with experience.' ___ 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 Knowledge Base: http://kb.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 Knowledge Base: http://kb.flex-radio.com/
Re: [Flexradio] Linux, any chance of a knoppix like setup?
Count me in on the groundswell... John Frank Brickle said the following on 01/01/2007 02:56 PM: If people want a consumer-oriented Linux version, there has to be a groundswell of popular support for it. Otherwise the individual Linux developers are going to continue to write to suit themselves, and that development is, for now, aimed almost exclusively at experimenters. ___ 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] Looking fo Rubidium standard
Edward J White wrote: Hi Gang: I am looking for a Rubidium frequency standard to run the SDR-1000 oscillator. I know others have done this to run 10 GHz. What is the best price and make model where and where should I be looking for one(I know the E place). Ed WA3BZT You may want to be careful about using one of the small Rb standards (like the Efratom FRS or FRK) for this application. They tend to have fairly bad phase noise because the reference frequency is FM'd as part of the lock system. An HP5065A Rb doesn't have this problem, but is a much bigger and more expensive beast. 73, John ___ 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] Audio Amp for receive
I recently built a 3 watt stereo amp from Carl's Electronics (http://www.electronickits.com). For $17.95, it's a very good deal. I put it in a simple metal enclosure and got nice audio, but am still having some RF issues. I'm now planning to repackage it in a Hammond box with bypassing on the I/O and -- I suspect this may be key -- transformer isolation on the inputs. John Radio Station W5AMI wrote: I wanted to ask the list members for a recommendation on an outboard audio amp to drive a pair of nice speakers that has proven to be resistant to RFI before I went out and bought something. I have considered building a tube amp using a pair of 6V6's, or 6AQ5's in push-pull output, but after pricing some good inter-stage and P-P output xfmr's, I've had second thoughts. I really want something to give me the freq. response the SDR1K can deliver when I choose to listen in that mode. Good speaker suggestions are also very welcome. My main concern is RF getting into the amp if I run the legal limit power. Any suggestions or recommendations will be much appreciated. By the way, I'm using the Delta 44 on my Flex, but I figure most any consumer or pro level audio amp would work fine with the output on the D-44 with proper adustment from -10 to +4 dB in the M-Audio console. TIA 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
Re: [Flexradio] Notebook computers
Robert McGwier wrote: My 2.4 GHz Sony Vaio is solid and fast. I need to clean it out because the fan is always on high but it is solid. I am reluctant to give it up for one of these throttling monsters that you can't choke off from throttle. My Dell laptop which runs Linux, has the throttle problem. It is great at 2.2 GHz but throttles back to 900 Mhz off the mains and will not go the other way, even if power is reapplied. Gr. So I understand that feeling. I had a Vaio several years ago, and it was an excellent computer. HOWEVER, it is impossible to get service information or parts from Sony. I needed to replace the hard disk and the only service info I could find on the Sony website was where to send it. I had the joy of figuring out how to open up the case (no easy task) without any documentation. Contrast that with the Thinkpad where IBM had full service manuals online, complete parts lists, all drivers individually available for download, and a very efficient/helpful parts ordering system. Thanks to that, I've replaced keyboards, power supply modules, etc. on a bunch of Thinkpads over the years. I don't know if that's changed since Lenovo, though. John ___ 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] Speaker Amplifier?
Hi Peter -- Not sure I follow... are you talking about ripping the amplifier board out of a speaker, or a separate box that's part of the system? I've only seen PC speakers with the amp built in. Thanks! John petervn said the following on 05/27/2006 11:13 AM: Hi John I use an amplifier from a PC speakerset, there are lots of them around in secondhand shops some with 230 / 127 volt power others with 12V DC maybe you can try that. good luck peter pa0pvn -Oorspronkelijk bericht- Van: [EMAIL PROTECTED] namens John Ackermann N8UR Verzonden: za 27-5-2006 16:19 Aan: FlexRadio@flex-radio.biz CC: Onderwerp: [Flexradio] Speaker Amplifier? I'm trying to tie my SDR-1000 into the rest of my station gear, and would like to use my NCS Multi-Switcher to select audio paths. I have a pair of unamplified communications speakers, and therefore need to come up with an amplifier for the SDR-1000 audio output. I'm sure I can build something up if I need to, but to avoid that hassle -- can anyone recommend a simple audio amplifier with a couple of watts output? Ideally, I'd like a stereo unit so I can play with binaural audio, etc. Small size would be good. Thanks and 73, John ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-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://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] Searchable archieves
Not speaking for the Flex-Radio team, but as someone who runs a Mailman list server... Unfortunately, Mailman doesn't support searchable archives out of the box. There are ways to do it (which the hpsdr folks must have figured out) but it takes patching Mailman and using additional software. The Mailman web site points you toward several ways of doing it, but doesn't give an official blessed solution. The patching requirement is a real concern, because that makes automated updates for, e.g., security issues, more difficult to manage. I've looked into it for the tapr.org and febo.com mailing list archives (which both use Mailman) and unfortunately it takes quite a bit more than just flipping it on. 73, John [EMAIL PROTECTED] said the following on 04/29/2006 11:33 AM: Yes, I agree w/ Lee here. I have had may Flex on the bench for abt 36 hrs now. It was just delivered to me on Thurs, and I have many questions that I know have been asked and answered a million times. I would LOVE to be able to search the archive as use them as a knowledge-base. I am sure the searchable feature is just a simple switch in the pipermail software. Someone needs to FLIP IT ON !!! Best Regards, -Dan K6KDK PS: So far the report the report on my new Flex is that The Flex Sure Makes Me Happy! (This is a not-so-very inside joke from those of you that follow the TT reflector, I am sure Lee will get a chuckle out of it anyway...) - Original Message - From: Lee A Crocker [EMAIL PROTECTED] To: FlexRadio@flex-radio.biz Sent: Saturday, April 29, 2006 8:14 AM Subject: [Flexradio] Searchable archieves How come the flex-radio archieves are not set up like this sites archieves? http://lists.hpsdr.org/pipermail/hpsdr-hpsdr.org/ Note these archieves are searchable. These people are certainly flex radio friendly, it would seem they might be willing to share a little advice on how to do this.
Re: [Flexradio] How to wire this up?
Jim Lux said the following on 03/19/2006 03:01 PM: At 11:34 AM 3/19/2006, Neal Campbell wrote: Hi guys I just bought a Bliley NV26R891 voltage controlled ovenized 100 Mhz crystal oscillator. Should it be possible to use it for external frequency standard for the SDR-1000? Any ideas on how to wire it up? Check out the external frequency reference ECO on the Flex website. Basically, you pull the existing 200 MHz oscillator out and feed your 100 MHz signal in. You need to tell PowerSDR that you're doing this, so it can turn on the internal frequency multiplier, et.c There's a gotcha -- the DDS chip has a multiplier range of 4 to 20, so in theory 100MHz doesn't work. You can use either 50MHz, or 200MHz. However, I had some success when I tried using a 100MHz source some time ago before I knew of the multiplier limitation. i.e., I got a signal out but I don't know what negative characteristics it might have had. John
Re: [Flexradio] VF-161, TCXO, OCXO Oscillator and DDS Phase Noise
Great work, John!!! I'm really looking forward to the actual SDR-1000 measurements to see whether the noise multiplication from the on-chip multiplier is according to theory or if there are other factors involved beyond simple scaling. I haven't had a chance yet, but will also compare your measurements to the ones I took over Xmas using the same Agilent box. 73, John [EMAIL PROTECTED] said the following on 02/04/2006 12:22 PM: Hello Enthusiasts, I've made several phase noise measurements and posted them at www.exothink.com/SDR. The first page shows plots comparing different quality oscillators suitable for use in the SDR1000. The second page contains several measurements at the DDS output. These graphs were generated in Excel so that different measurements could be plotted on the same graph. I also have a couple dozen virgin instrument screen dumps that I'll add at a later time. Several measurements have also been made on the SDR1000 to provide insight on how the phase noise LO performance relates to real world receiver performance. I'll let you know when I get these posted.
Re: [Flexradio] Beginners - Experts - Terminology and stuff
Hi Gerald -- My $0.02: First, I think the mailing list(s) are a huge improvement over the forums. It's an issue of push vs. pull -- I'm much more likely to read an email that ends up in my inbox than I am to remember to go to the forum and work my way through the postings. Forums are great for long-term availability of info, but (IMHO) they are a horrible approach to near-real-time discussion (and, for me at least, the email interface is a lot more efficient way to read and reply; there are far fewer clicks involved). Second, I think you might consider three reflectors: flex-radio for general, non-technical discussion, flex-radio-beta for discussion of beta bugs and features, and flex-radio-futures for the Xylo/FPGA/Linux etc., etc. conversations. If you only want two lists, I'd separate out the beta discussions. Moving discussion of beta version problems/requests/etc. to its own list would reduce both traffic *and* is this a finished product or not confusion on the main list. 73, John Gerald Youngblood wrote: Eric E., Thanks for some very succinct explanations. Let me put forth a couple of concerns we have about how to best use the reflector and forum resources. Due to the nature of a software radio, we will always be releasing new beta software that will have bugs. The discussion on this reflector of beta bugs has been a huge source of confusion to new and potential customers. It gives the impression that the radio is unstable or unfinished. Five years from now this will still be an issue unless you the users and we the manufacturer have run out of good ideas. Somehow I doubt that. Our wish list is longer today than it was three years ago when we shipped serial number uno. We have thought of creating a Beta and Experimental Reflector to separate the discussion of the new and experimental stuff from that of the officially released software. It could potentially make it less intimidating to the new user and the potential customer. I agree that splitting the reflector could dilute the resources who help the new user. The email reflector has been a big improvement in some ways over the Forum because it is much more real time. It has been a great help to FlexRadio because many of you know more than we do about specific applications of the radio. The Forum may actually be better from a FAQ standpoint but it can become out of date very quickly as the software evolves. Since the reflector started, the traffic on the website Forum has gone down dramatically. This indicates to me that the immediacy of the reflector meets the needs of the larger population better than the Forum. However, the Forum has the ability to organize archive topics in a much more user friendly way than the reflector. It also has the capability to imbed easily graphics. With that said, I am very interested in hearing your thoughts on how we can better serve the diverse needs of the neophyte to the advanced experimenter. All are important the hobby of amateur radio. I would like to know what you think about the following: 1) Should we create a separate reflector for Beta Software and Experimental Topics? The proposal would keep this reflector with a general interest and support focus. 2) How can we better utilize the website Forum, which now has fairly low traffic? Would it help to have volunteer moderators who monitor the Forum to make sure people get their questions answered? 3) How do we address the misperception of product instability caused by the never ending improvements that will come in the software over the years? 4) How do we make sure that new users and potential users feel comfortable posting their questions? How do we make sure they get the answers they need? Your comments are welcome. 73, Gerald Gerald Youngblood, K5SDR President FlexRadio Systems 8900 Marybank Drive Austin, TX 78750 Ph: 512-250-8595 Email: [EMAIL PROTECTED] Web: www.flex-radio.com http://www.flex-radio.com/ _ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Eric Ellison Sent: Thursday, February 02, 2006 11:19 PM To: Flexradio@flex-radio.biz Subject: [Flexradio] Beginners - Experts - Terminology and stuff Folks A Reflector member contributed a PM suggesting that I clarify some of the terms the I, and others have been using on the Reflector since the acronyms can be daunting to recent members reading. I find this a very reasonable request. I'll start with that: FPGA (Field Programmable Gate Array) An integrated circuit which is essentially a hardware etch-a-sketch. About 4 manufacturers make them. You actually write a program with tools offered by the manufacturer and create your own customized integrated circuit. It can be just about anything, from a microprocessor to a high speed counter, to a light switch, when you press the button it lights the light. Price range is $10 to $1800. It is an order of magnitude beyond a PIC
Re: [Flexradio] 160 Meter Filter?
For what it's worth, I have had very good luck with high-pass filters by I.C.E. which I think are sold through Array Solutions. They have two versions -- one with a cutoff just below 160M, and one with a cutoff just below 80M. They handle 100 watts so can be put in the antenna line after the rig. I have very strong local BCB here (like -3dBm at the bottom of the coax) and these filters are needed for use *anywhere* on HF. They make a huge difference. In my case, since I don't have an antenna for 160, I use the 80M version which has much better rejection. 73, John N8UR [EMAIL PROTECTED] Larry W8ER wrote: Jeff et all, the filter that is supplied with a new Flex Radio is a low pass filter. It does not attenuate broadcast band signals. There is a problem with the SDR-1000 (many other radios too) when you live in an area that has broadcast stations in the area. Broadcast station images appear in the 160 meter band. The Flex that I just sold was sent back to Flex and had a bandpass filter installed in place of the low pass front end filter that is standard. 160 meter operation is flawless with this mod! If you normally listen to broadcast stations however, you will not be able to do that after the new filter is installed. I am sure that Gerald or Eric can supply the information on what is needed to make this change. It is a couple of new inductors and caps and can be done by the owner without shipping it back if you are handy with the iron. If all you have is a blowtorch however ... you might want to send it back! --Larry W8ER - Original Message - From: Jeff Anderson To: Flex Reflector Sent: Thursday, January 26, 2006 2:05 PM Subject: [Flexradio] 160 Meter Filter? Does anyone know what 160 meter filter Larry is referring to? I've noticed that I have horrible Broadcast Band images appearing throughout 160 meters, and I was going to roll my own filter, but...is there an official Flex-Radio or a recommended after-market filter that I could also use? Thanks! - Jeff, WA6AHL - Original Message - From: Larry W8ER To: Flex Reflector Sent: Thursday, January 26, 2006 12:52 PM Subject: [Flexradio] Flex SDR-1000 For Sale Reluctantly I am selling my SDR-1000. It has the 100 watt amplifier and the built in antenna tuner. It is approximately 1 year old. It also has the 160 meter bandpass filter for anyone that is bothered by local broadcast stations on 160 meters. I will include the Delta 44 sound card and all cables. It is perfect in most every way. It is available immediately for $1450 plus shipping of your choice. email at [EMAIL PROTECTED] or 440-967-0654 --Larry -- ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://mail.flex-radio.biz/pipermail/flexradio_flex-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://mail.flex-radio.biz/pipermail/flexradio_flex-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://mail.flex-radio.biz/pipermail/flexradio_flex-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://mail.flex-radio.biz/pipermail/flexradio_flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
Re: [Flexradio] ARRL FMT: one more win for the SDR-1000
Jim Lux wrote: At 05:58 AM 1/19/2006, John Ackermann N8UR wrote: Jim Lux wrote: Of course... the SDR1000 does have an advantage because it's a very simple receiver with fewer stages to screw things up. While the SDR-1000 can do a credible job on its own, I just want to reinforce that anyone with a signal generator that's locked to a decent reference, and a sound card, can measure to small fractions of a Hertz using the delta reference method I describe at http://www.febo.com/time-freq/fmt/technique.html. You don't need a lab full of expensive gear to do it. Indeed.. The two accuracy limiting things in John's scheme that I see are: 1) Group delay variations across the band in the presence of any drift. If the unknown and the reference move across the passband, and there's some group delay ripple, the relative phase will change between the tones. If you're integrating for 10 seconds, a phase change of 360 degrees would be a 0.1 Hz error. THis might be an area where older receivers using a long string of tuned LC networks for selectivity would be at disadvantage (because each section flips the phase 180 over the passband, and they all add up). You also clearly don't want that exotic 10 Hz CW crystal filter in the circuit. Yup. I normally use a fairly wide bandwidth; in fact, for the last test, I used the widest 3100Hz bandwidth in the 3586C selective level meter; good thing I did, too, as I mistuned on a broadcast hetrodyne on 40M, and only after the fact did I find W1AW 1kHz away, but still in the bandpass. 2) Uncertainty in the sampling clock of the audio card. I suppose that one can calculate this by measuring the frequency of the known reference at two frequencies. A lot of signal generators have a way to put an AM modulation on the signal with precisely controlled frequency, and that would give you two marks, say, 400 Hz apart, with which to calibrate the FFT box. We've been around the soundcard clock issue several times on the list. An advantage of the delta reference method is that you don't care about the absolute frequency, only the delta between two closely spaced frequencies. So the clock error is applied to a smaller number (the delta between the two tones) and thus has less absolute impact than if you were measuring absolute frequency. My measurements of the Delta 44 card I use shows that its clock error is in the noise for this test. Remember that frequency measurement in the HF range doesn't really require a super-accurate source -- 1x10e-8 gets you down to 0.1Hz at 10MHz. That level of accuracy can easily be met with a $100 surplus ovenized oscillator (like an HP 10811A or the older 10544), a GPS receiver, and a $100 surplus counter like the HP 5334 (my personal low-cost favorite)*. And that's assuming you're fairly fumble-fingered. With a bit of care, you can set to at least one, and maybe two, orders of magnitude better than that (though the aging rate will limit how long that accuracy holds). The GPS receiver needs a 1pps output of some sort. (I tried this with a serial output only once, and while the timing of the messages was reasonably stable, it wasn't great: about 1ms uncertainty) Yes, I should have said that. The good news is that there are lots of old Oncore receivers available for a pittance that will do the job. 73, John
Re: [Flexradio] Fwd: Re: ARRL FMT: one more win for the SDR-1000
Jim Lux wrote: The soundcard program I used, Argo, permits a frequency calibration coefficient to be entered. I used the 1800 Hz third harmonic of the WWV/WWVH 600 Hz tone as demodulated by the TS-870S in its AM mode as a calibration standard. When ionospheric fades null the carrier, the demodulator distortion peaks and makes the audio third harmonic visible in the Argo spectrogram. Argo is a really excellent tool; one of the guys who does the multi-multi FMT with me uses it and it has some very cool features for this application. And cool idea about using the distortion to get a calibration source! John
Re: [Flexradio] ARRL FMT: one more win for the SDR-1000
Eric Ellison said the following on 01/18/2006 07:01 PM: Anybody ever wonder if folks out here have even better equipment than ARRL for generating the test? Sort of would be fun for folks like yourself, Tom, JPL?, John or others, with access to millions of dollars in equipment to do the Test. Several of us on the time-nuts list participated. The equipment ARRL uses is nothing all that special -- a Z3801A GPS-disciplined oscillator clocking a surplus HP frequency counter. The interesting thing is that (at least last year) the audio tone generator they used was an old Heathkit! That makes frequency stability during the test a real issue, and means that you need to be careful to measure each band during the time that ARRL is. I should go back to my data and see what the tone was on a single band at the beginning versus the end of the test. I am pretty confident that I can measure a CW tone off the air down to a few milliHertz accuracy given a minute of more of carrier to work with (and enough lead time to get the measurement gear in the ballpark). Of course, propagation can cause wiggles much greater than that, so you need to take my X.XXXHz readings with that in mind (and ARRL only reports their measured frequency to two decimal places). 73, John
Re: [Flexradio] ARRL FMT: one more win for the SDR-1000
Jim Lux said the following on 01/18/2006 07:36 PM: At 04:24 PM 1/18/2006, John Ackermann N8UR wrote: Eric Ellison said the following on 01/18/2006 07:01 PM: Anybody ever wonder if folks out here have even better equipment than ARRL for generating the test? Sort of would be fun for folks like yourself, Tom, JPL?, John or others, with access to millions of dollars in equipment to do the Test. Several of us on the time-nuts list participated. The equipment ARRL uses is nothing all that special -- a Z3801A GPS-disciplined oscillator clocking a surplus HP frequency counter. The interesting thing is that (at least last year) the audio tone generator they used was an old Heathkit! That makes frequency stability during the test a real issue, and means that you need to be careful to measure each band during the time that ARRL is. I should go back to my data and see what the tone was on a single band at the beginning versus the end of the test. I am pretty confident that I can measure a CW tone off the air down to a few milliHertz accuracy given a minute of more of carrier to work with (and enough lead time to get the measurement gear in the ballpark). As I recall, you can measure the phase of a tone with an uncertainty of 1/sqrt(T * CNR), where T is the integration time, and CNR is the carrier to noise spectral density ratio (C/Nzero). If you've got a SNR of say, 10 dB in a 2kHz bandwidth, that's a CNR of 2, or a phase uncertainty for a 50 second measurement of 1/1000 radian (0.057 degree?) I can't recall off the top of my head how to convert a phase uncertainty into a frequency uncertainty (frequency just being the derivative of phase), but it should be straight forward. I haven't worked through that bit of math, I'm just going on the results we've gotten. The method I use is to inject a known signal very close (within, say, 100Hz) of the unknown signal, and measure the delta between the two using a sound card. By using a high decimation rate and reasonably deep FFT, you can get resolution down well below a milliHertz. The problem is getting enough samples to fill the FFT; you end up dealing with an effective sample rate after decimation of maybe a few hundred samples/second, which means that you need a long time to get a useful output from the FFT. The software I use, Baudline (http://www.baudline.com) is a Linux based spectrum analyzer package that has some neat features, including the ability to automatically measure the delta between two signal peaks. It makes the whole process pretty easy. It would be interesting to figure out a more meaningful competition, where ionospheric effects are compensatable, if you're clever. Perhaps measuring the relative phases/frequencies/amplitudes of multiple tones that are reasonably close together? Something that could be normalized to your propagation path. Otherwise, the guy sitting in the parking lot at W1AW has a huge advantage. Maybe, your results are scaled by the SNR or something? We've thought a little about what kind of format would be really challenging for the test, and measuring the delta between two tones is one interesting idea. None of the folks I've talked to very much like the format of the last two years, where you have to reduce to an audio tone that's meaningless because the transmission in in SSB mode. 73, John
Re: [Flexradio] DIP OCXO for SDR
I'm traveling for a few days and don't have all my stuff handy, but Gerald pointed me to a device from (I think) Silicon Industries in Texas that looks very promising. They have VCXOs up to 400MHz that have some sort of on-board divider/synthesizer/nco so they can deliver any frequency in range with short lead time. The phase noise doesn't look too bad, either. It's the part I'm focusing on right now for the Reflock unit. I want to say the part number is something like Si520, but that may be wrong. John Eric Ellison said the following on 01/07/2006 11:08 PM: Tim Thanks. I swear that Gerald said the current VF part was sine wave output. I saw the posts about the Greenray a while back and just don't know. This is the first time in my searches that I found a 200 mhz VC part which is available without horrific lead times and no quantity one. If the Crystek part will work in our external closed loop design to drive the SDR accurately then I'm for giving it a shot. That price is not bad either. At times I had seen $80 + parts and they were not low phase noise, or voltage controlled, just +/- 25 ppm TC parts. Although this is a 50 ppm part I think that I saw it could be pulled +/- 500 ppm. Thanks for the response. Comments? Eric2 -Original Message- From: Tim Ellison [mailto:[EMAIL PROTECTED] Sent: Saturday, January 07, 2006 10:32 PM To: Eric Ellison; John Ackermann N8UR Cc: [EMAIL PROTECTED]; FlexRadio@flex-radio.biz Subject: RE: [Flexradio] DIP OCXO for SDR Eric, The VF VCXO listed below has a max frequency at 200 MHz. The XO currently in use, the VF 161 has a max frequency of 300 MHz. Using a device at either end of its rated frequency may suffer from precision and/or accuracy errors. The Crystek is much closer, but the output is a sine wave rather than PECL(positive emitter coupled logic) which is the output of the current XO. I am not sure if this will make a difference or not with the devices being designed. I did find this VCXO that is very close to the VP161 from Greenray, but I received some less than satisfactory comments about the company http://greenrayindustries.com/library/ZT620.pdf -Tim --- Tim Ellison ( [EMAIL PROTECTED] ) Integrated Technical Services ( http://www.itsco.com ) -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Eric Ellison Sent: Saturday, January 07, 2006 9:01 PM To: 'Eric Ellison'; 'John Ackermann N8UR' Cc: [EMAIL PROTECTED]; FlexRadio@flex-radio.biz Subject: Re: [Flexradio] DIP OCXO for SDR John (and others on this thread) Magnus - SM4RWI mailed me off list of a Valpey Fisher 200 VCXO offering with low phase noise. The VF 960/961. I could not find any ready sources for this part and did not request sample or quote. However, it is a pretty nice piece. http://www.mfelectronics.com/products/vcxo/ I decided to go back out and do my occasional search for an available part with low phase noise and 200 mhz VC. Newark is supplying a Crystek 200 mhz VCXO in stock for about $45 Dip and $58 smt. See PDF. http://www.crystek.com/spec-sheets/CCO-083_085.pdf http://www.mouser.com/catalog/624/656.pdf If we are talking about temp stabilizing and disciplining external to the radio, these might be good considerations for the conventional (not computer or FPGA aided) GPS - 10 mhz phase locking system. Someone could take a look and see if the specs are acceptable. Eric2 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Eric Ellison Sent: Friday, January 06, 2006 4:17 PM To: 'John Ackermann N8UR' Cc: [EMAIL PROTECTED]; FlexRadio@flex-radio.biz Subject: Re: [Flexradio] DIP OCXO for SDR John Yes! Gerald HAS really moved a lot of lives with something that actually works, is available, and works very well! It sure has spawned a LOT of interesting projects and experimentation. I agree totally that we should 'brainstorm' a solution for getting the 200 mhz off or on, or around, and or back into the SDR-1000. Something fairly flexible and not too difficult to accomplish. I don't think that any of this is in conflict with others, and nothing is really 'fractionating' the mass of folks in spite of 'parallel' projects going on. If anything we are getting some crosspollination. At this point having gone about as far as we can go with ECO's in this hardware, we are just 'branching out' into associated areas, where former focus was investigating how to directly improve the SDR-1000. Any comments from readers as to how we actually pull the VF osc, buffer it? Parts? Schematics? Block diagrams. Designs (not talk!). Thanks Eric2 -Original Message- From: John Ackermann N8UR [mailto:[EMAIL PROTECTED] Sent: Friday, January 06, 2006 9:16 AM To: Eric Ellison Cc: [EMAIL PROTECTED]; FlexRadio@flex-radio.biz Subject: Re: [Flexradio] DIP OCXO
Re: [Flexradio] DIP OCXO for SDR
Eric Ellison wrote: [ everything trimmed ] It sounds like there are several groups doing a lot of interesting things with FGPAs that extend way beyond just frequency stability. I think that's really great, and thank Gerald for creating such a great base for creative people to play. From my (and TAPR's) perspective, we want to do a Reflock-based design because it will have a broader use than just the SDR-1000. For example, with a 64MHz VCXO, it can work with the Ettus Research USRP software radio. I can also see it serving as an external clock for a sound card to eliminate that source of frequency uncertainty. So, I don't see any conflict at all between what we're doing and the other approaches. The one SDR1k specific item I'd like to see, whether TAPR produces it or Gerald does, is a civilized board that will plug into the reference oscillator socket to allow a better interface to an external signal. I've started looking into that and we'll work with Gerald to figure out how best to offer that. It's mainly a matter of finding a buffer/level converter chip that will take a single-ended input and convert it to a differential signal at the right level for the DDS chip (suggestions welcome; I've started researching the chipmaker sites, but haven't found an obvious answer yet). 73, John
Re: [Flexradio] DIP OCXO for SDR
Great plan, John. I only had access to the 5052A for a day, so was pretty limited in what I could do; it's great that you'll be able to carry things forward. The one addition I would suggest is that you duplicate the DDS output measurements using the 10MHz source as well as the VF oscillator. That would add to my sketchy info about the effect of the multiplier on phase noise. I was not happy with the results I got, I think due to the way I was coupling out of the DDS, which was essentially a x1 scope probe with less-than-perfect grounding. After the fact, I redid the connection with a 50 ohm series resistor at U1 pin 6 (actually, mounted into a via on that line) and a short piece of RG-174 feeding a buffer amplifier. I think something like that will give better results. By the way -- I looked at the AD9854 data sheet and it includes several phase noise plots. From those, you would gather that there is a cost in using the internal multiplier, but that it doesn't scale with DDS output frequency. Also, from a quick read you could get the impression that the phase noise of the reference clock doesn't really matter (within reason, of course); they show the output phase noise plot without any reference to the noise of the clock. 73, John [EMAIL PROTECTED] wrote: This is cool. It's great to be able to discuss the nuances of what really goes on within our radios. Spreading the word is a very good thing. I checked out John's(N8UR) web site and I'm inspired. I have an E5052A Signal Source Analyzer setting here and plan to make a few measurements. Here's the plan so far: i. measure phase noise of a 10MHz crystal (it will probably be limited by the E5052A) ii. the 200MHz VF1611 iii. DDS output with VF1611 as the clock at: 1MHz 5MHz 10MHz 50MHz Anyone have any additional ideas? I'm all ears. 73, k2ox -Original Message- From: richard allen [mailto:[EMAIL PROTECTED] Sent: Wednesday, January 04, 2006 5:39 PM To: John Ackermann N8UR Cc: [EMAIL PROTECTED]; FlexRadio@flex-radio.biz Subject: Re: [Flexradio] DIP OCXO for SDR Gentlemen, The DDS does Direct Digital Synthesis hence the name. It does not divide back to anything but runs an phase accumulation engine at 200 MHz (or whatever the clock rate) that produces output values to the dac at that rate. No division is performed. Richard W5SXD John Ackermann N8UR [EMAIL PROTECTED] wrote: (01/04/2006 16:09) [EMAIL PROTECTED] wrote: First of all, any osc multiplied up widens its sidebands (phase noise) by the multiplication factor and the inverse is also true. The DDS does a 20X to 200MHz and a divide by 20 to get back to 10MHz. I guess it's academic at this point how much jitter is added by the DDS until someone measures it. You're only dividing back to 10MHz if that's the operating frequency. At higher operating frequencies, the division doesn't equal the multiplication (and of course, at lower ones it exceeds it). Measuring the DDS output lets us see the phase noise where it counts, taking into account both multiplication and division, rather than just at the fundamental frequency of the reference. Second, Rubidium standards are not intended to be used as local oscillators. They have terrible phase noise. They are intended to be used in timekeeping. It is their long term drift that excels, not short term phase noise. Agreed in general -- though there's a wide difference in performance between different types of Rb; some use FM modulation of the xtal, which results in horrible phase noise, while others, like the 5065A, don't. My post wasn't suggesting that you use an Rb as the primary reference. However, the DDS output when driven by 10MHz shows the effect of the multiplication, which is all I was trying to do. My web page also has a plot of the HP 5065A phase noise at 10MHz, so you can see the difference in noise between the raw and multiplied frequencies. John http://www.febo.com/geekworks/sdr1k/sdr1k_phase/index.html has screenshots that show the phase noise at the output of the DDS for the standard 200MHz oscillator, and an HP Rubidium frequency standard at 10MHz multiplied by 20 in the DDS. You can clearly see the phase-noise hit caused by the multiplication. John ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Re: [Flexradio] DIP OCXO for SDR
Sorry I couldn't join in the fun; just too many things going on. TVB's PIC divider is a really elegant hack, and works very well. I'm currently working on a project for TAPR for a universal divider (to take any common frequency standard output and drop it to 1pps) and started out planning to use the PIC design, but changed to a CPLD because that offered more flexibility (or at least a more comprehensible programming model) for what I was trying to do, which has more options than Tom considered. I suspect that if you're doing something with an FPGA or CPLD anyway, you'll have the gates available in that chip to do the division without having to add another device, so I'd consider that first before adding another block to the system. John Eric Ellison said the following on 01/05/2006 07:14 PM: Folks Missed you on our Teamspeak session last night It's about time! Had a good discussion amongst a few people working on both the projects (Xylo) and Flex. Guess the fantastic Texas - USC entertainment got most others! Bob K5KDN is working on a Timebase board, chassis etc and has a Jupiter and nice 10 mhz Ovenized VCXO interfaced and building a board which will squat down on the DIP connector on the Jupiter. On the Xylo side Bill - KD5TFD published a picture of his breadboard of the Jupiter interfacing to the Xylo board, which will eventually pass frequency/phase information back to the PowerSDR software. I am looking for more information on anyone who has produced a complete circuit design published here several months ago by Tom Clark. Based on an original design by Tom van Baak and enhanced by Tom Clark. This is really an inspired design! PIC header is published here without permission, however, I did not note a copyright, and Tom made it available on the Forum several months ago. If it uses 10 MHZ this is the way to go! ; -- ; ; Title: ; ; 10 MHz frequency divider ; ; Function: ; ; This PIC 16c84 program is designed to divide a 10 MHz frequency ; source down to 1 Hz (1 PPS). ; ; Since several extra output pins are available the program creates ; a total of 9 square wave outputs -- one for each frequency decade ; from 100 kHz to 0.001 Hz (1000 s). ; ; A STOP input and a 1 PPS synchronization input are also provided. ; Raising the STOP input high stops and resets the divider. The ; divider resumes on the leading edge of the 1 PPS SYNC input. The ; 1 PPS output will be synchronized to the 1 PPS SYNC input to less ; than 1.2 us (three PIC instructions at 10 MHz). ; ; The following chip schematic shows the assignment of each pin. ; ;-- -- ; 100 kHz - RA2 |1--- 18| RA1 - Red LED ; Green LED - RA3 |2 17| RA0 = Stop input ; 1PPS SYNC = T0CKI/RA4 |3 16| OSC1/CLKIN = 10 MHz input ;+5 VDC - /MCLR |4 15| OSC2/CLKOUT -- N/C ; GND - Vss |5 16C84 14| Vdd - +5 VDC ;10 kHz - INT/RB0 |6 13| RB7 - 1000 s ; 1 kHz - RB1 |7 12| RB6 - 100 s ; 100 Hz - RB2 |8 11| RB5 - 10 s ;10 Hz - RB3 |9 10| RB4 - 1 Hz / 1 PPS ;--- ; ; Implementation: ; ; To generate a 10 kHz square wave at 50% duty cycle an output pin ; must be flipped every 50 us (125 instructions at 10 MHz clock). ; This program does not use TMR0, the pre-scaler, or interrupts. ; Instead it relies on the fact that given an accurate 10 MHz clock ; each PIC instruction takes precisely 400 ns and the main loop has ; been designed to use exactly 125 instructions. ; ; The 100 kHz frequency (10 us period) is generated by setting an ; output pin on and off every 25 cycles. Since 25 is an odd number ; it is not possible for the PIC to generate this square wave with ; a 50% duty cycle. Instead a 20% duty cycle (5 cylcles on and 20 ; cycles off) was chosen for this frequency output. A total of 5 ; pairs of 100 kHz bit set/clear code are carefully interspersed ; within the 50 us main loop. ; ; Pins RA0 and RA4 are not used to drive a LED. RA4 is a Schmidt ; trigger input and O.C. output. It is used as the SYNC input. ; The data sheet says not to toggle RA0 under some conditions so ; it is used as the STOP input. ; ; Version: ; ; 1998-Aug-05, Version 4, tvb ; ; -- ; Using Microhip assembler. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of John Ackermann N8UR Sent: Thursday, January 05, 2006 1:49 PM To: [EMAIL PROTECTED] Cc: FlexRadio@flex-radio.biz Subject: Re: [Flexradio] DIP OCXO for SDR Great plan, John. I only had access to the 5052A for a day, so
Re: [Flexradio] DIP OCXO for SDR
Jim Lux wrote: At 10:11 AM 1/4/2006, [EMAIL PROTECTED] wrote: The SDR1000 can use clocks between 10MHz and 200MHz so long as when multiplied by an integer it equals 200 MHz. I use a 10MHz TCXO. 73, k2ox However, when you multiply up using the internal VCO, the phase noise takes a hit. You might wind up with poorer noise (but more accurate frequency) multiplying up from a 10 MHz TCXO. http://www.febo.com/geekworks/sdr1k/sdr1k_phase/index.html has screenshots that show the phase noise at the output of the DDS for the standard 200MHz oscillator, and an HP Rubidium frequency standard at 10MHz multiplied by 20 in the DDS. You can clearly see the phase-noise hit caused by the multiplication. John
Re: [Flexradio] DIP OCXO for SDR
[EMAIL PROTECTED] wrote: First of all, any osc multiplied up widens its sidebands (phase noise) by the multiplication factor and the inverse is also true. The DDS does a 20X to 200MHz and a divide by 20 to get back to 10MHz. I guess it's academic at this point how much jitter is added by the DDS until someone measures it. You're only dividing back to 10MHz if that's the operating frequency. At higher operating frequencies, the division doesn't equal the multiplication (and of course, at lower ones it exceeds it). Measuring the DDS output lets us see the phase noise where it counts, taking into account both multiplication and division, rather than just at the fundamental frequency of the reference. Second, Rubidium standards are not intended to be used as local oscillators. They have terrible phase noise. They are intended to be used in timekeeping. It is their long term drift that excels, not short term phase noise. Agreed in general -- though there's a wide difference in performance between different types of Rb; some use FM modulation of the xtal, which results in horrible phase noise, while others, like the 5065A, don't. My post wasn't suggesting that you use an Rb as the primary reference. However, the DDS output when driven by 10MHz shows the effect of the multiplication, which is all I was trying to do. My web page also has a plot of the HP 5065A phase noise at 10MHz, so you can see the difference in noise between the raw and multiplied frequencies. John http://www.febo.com/geekworks/sdr1k/sdr1k_phase/index.html has screenshots that show the phase noise at the output of the DDS for the standard 200MHz oscillator, and an HP Rubidium frequency standard at 10MHz multiplied by 20 in the DDS. You can clearly see the phase-noise hit caused by the multiplication. John ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Re: [Flexradio] DIP OCXO for SDR
Richard, that's a question I've been meaning to ask someone -- whether there's any phase noise improvement resulting from the (apparent) division of the clock signal by the DDS, or whether the output phase noise is always the same as, or worse than (due to imperfection in the DDS process), the reference. John richard allen said the following on 01/04/2006 05:39 PM: Gentlemen, The DDS does Direct Digital Synthesis hence the name. It does not divide back to anything but runs an phase accumulation engine at 200 MHz (or whatever the clock rate) that produces output values to the dac at that rate. No division is performed. Richard W5SXD John Ackermann N8UR [EMAIL PROTECTED] wrote: (01/04/2006 16:09) [EMAIL PROTECTED] wrote: First of all, any osc multiplied up widens its sidebands (phase noise) by the multiplication factor and the inverse is also true. The DDS does a 20X to 200MHz and a divide by 20 to get back to 10MHz. I guess it's academic at this point how much jitter is added by the DDS until someone measures it. You're only dividing back to 10MHz if that's the operating frequency. At higher operating frequencies, the division doesn't equal the multiplication (and of course, at lower ones it exceeds it). Measuring the DDS output lets us see the phase noise where it counts, taking into account both multiplication and division, rather than just at the fundamental frequency of the reference. Second, Rubidium standards are not intended to be used as local oscillators. They have terrible phase noise. They are intended to be used in timekeeping. It is their long term drift that excels, not short term phase noise. Agreed in general -- though there's a wide difference in performance between different types of Rb; some use FM modulation of the xtal, which results in horrible phase noise, while others, like the 5065A, don't. My post wasn't suggesting that you use an Rb as the primary reference. However, the DDS output when driven by 10MHz shows the effect of the multiplication, which is all I was trying to do. My web page also has a plot of the HP 5065A phase noise at 10MHz, so you can see the difference in noise between the raw and multiplied frequencies. John http://www.febo.com/geekworks/sdr1k/sdr1k_phase/index.html has screenshots that show the phase noise at the output of the DDS for the standard 200MHz oscillator, and an HP Rubidium frequency standard at 10MHz multiplied by 20 in the DDS. You can clearly see the phase-noise hit caused by the multiplication. John ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Re: [Flexradio] Software taming the wandering oscillator - a thought
Eric Ellison said the following on 01/02/2006 06:25 PM: This is the way to go for three projects. Pardon my ignorance, but is the V-F Osc a pluggable part? This is the best of all worlds. Unmodified, the Yes, it's a can oscillator with 4 pins. It basically has the same footprint as a 14 pin (I think) DIP package, but with only four pins, one at each corner. John
[Flexradio] Measuring the SDR-1000's latency
While I was setting up to record audio from several radio time sources for the leap second last night (my leap second web page is at http://www.febo.com/time-freq/leapsecond-2005), I realized that it would be easy to use the same configuration to measure the delay of the audio output of the two receivers (SDR-1000 and Yaesu FT-817) when both were tuned to the same signal on the same antenna. I ran that experiment today, using WWV on 15MHz. The short answer is that with my setup, the delay is 187.6 milliseconds. More detailed results, with screenshots, are at http://www.febo.com/geekworks/sdr1k/sdr1k_latency. I was using 1.4.5 preview 4 and the DSP buffer size was set to 2048; the sound card buffer size was 1024. I think these were the defaults when I installed the software, but if they're not appropriate, someone let me know and I can rerun the experiment with different values. More details about the test setup are at the web page. Happy New Year! 73, John
Re: [Flexradio] A question on Frequency stability vs. Temperature
Insulation will slow down the response to external temperature variations, but unless there's a heat source inside the insulated area, it won't prevent the change (sooner or later, the internal temperature will match the external). One very simple answer, that I think Gerald has been playing with, is to use a heating element to raise the temperature of the oscillator above the ambient. In a packet radio project many years ago, I was working with Kantronics UHF data radios that had horrible temperature stability that was exacerbated by the fact they were used in non-temperature controlled environments. We tried a couple of ways to fake a crystal oven. The easiest, and most successful, was a crystal heater that you could buy from the Yaesu parts department. It was a power thermistor mounted to a clip that would slide over the crystal can. Attached to 12 volts, it would heat the crystal up to something over 100 degrees F (we never measured the exact temperature). Those solved our temperature stability problems, but I suspect that it cooked some of the crystals (which were spec'd for room temperature operation) because after a couple of years we found some rocks that would no longer net to frequency. Something similar might work with the V-F oscillator can. John [EMAIL PROTECTED] said the following on 12/31/2005 07:31 AM: Folks Yes, Bob N4HY mentioned on Teamspeak that he had 'insulated' the osc with some material which cut down on drift. Perhaps he could elaborate a bit more on the scheme he used. Eric2 -- Original message -- From: KD5NWA [EMAIL PROTECTED] I've heard it on Teamspeak that when a scheme like that has been tried it worked very well. Thermal stability like you mentioned, along with electronic compensation of the clock by comparing it to a GPS clock is one of the projects the Xylo will be used for. At 12:49 AM 12/31/2005, Tim Ellison wrote: I have a question about frequency stability of the SDR1K in regard to variable temperatures inside the SDR1K. The reason for concern is frequency drift while working digital modes. For the sake of this argument and staying on point, let's assume that the frequency delta is significant, although in reality it probably is insignificant. Some initial background information. I am seriously thinking about installing a temperature-proportional cooling fan speed controller in the SDR1K to further reduce fan noise. The controller is not designed to provide a stable temperature (thermostatically controlled), it just increases the fan's RPMs as the temperature increases until it reaches max RPMs @ 105 F. I assume that since the fan is not providing constant CFM air flow, under high duty cycle operation, there will be a more rapid rise in temperature until the fan is running at full speed, at which some level of temperature equilibrium is reached, as opposed to having the fan run at full speed all the time resulting in a temperature change that would be less drastic. The net effect is that the internal temperature will vary more with the fan controller therefore resulting in more drift in the XO. I am aware of the ability to use external precision clock sources to more precisely drive the DDS, but in my current configuration, the Valpey-Fisher VF-161 XO is utilized and is sensitive to frequency drift with changes in temperature. From the specs, the max temperature for the XO is 85 C and the stability is +/- 20 ppm. http://www.valpeyfisher.com/PDFs/vf161_E.pdf Assuming temperature stabilization is warranted, my question is this - what advantages / disadvantages would there be for trying to minimize temperature variations of the OX by adding some insulating material (Styrofoam maybe) around the XO or by adding an external precision crystal heater ( @ 40 C) to *stabilize* the temperature at a fixed value and hence the frequency drift? An example of the precision crystal heater is found here: http://www.kuhne-electronic.de/english/special/crystalheater.htm Any and all comments welcome. Thanks! -Tim --- Tim Ellison Integrated Technical Services Apex, NC USA 919.674.0044 Ext. 25 / 919.674.0045 (FAX) 919.215.6375 - cell PGP public key available at all public KeyServers ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Cecil Bayona KD5NWA www.qrpradio.com I fail to see why doing the same thing over and over and getting the same results every time is insanity: I've almost proved it isn't; only a few more tests now and I'm sure results will differ this time ... ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Re: [Flexradio] External clock problems
did you change jumpers SV1 and SV2 (which switch between differential and single-ended clock input for the DDS chip)? I'm not sure what difference that might make; when I did my phase noise tests, the jumpers didn't seem to make much difference. One other possibility might be a ground loop problem. 73, John Bob Tracy said the following on 12/30/2005 05:42 PM: Hi, Has anyone had any experience using an external clock with the SDR-1000 they would like to share? I built a 10 mHz GPSDO that seems to be working just fine. It puts out a nice 1.7 V P-P sine wave into a 50 ohm load which is within the +4 to +14 dBm range required by the SDR-1000. I installed the FlexRadio External Clock kit which is just a 14 pin header, some coax, a bnc, and a 50 ohm resistor. When I try to use the external clock, I get really distorted audio coming out of the radio. I have switched back to the internal oscillator a couple of times just to make sure the problem really was in the external circuit. The radio works normally using the internal oscillator. I don't see any garbage on the external oscillator signal using a 100 mHz scope. One other mystery is the amplitude calibration of the SDR-1000 itself. I am calibrated at -73 dBm using an XG-1 calibrator. When I connect the external oscillator to the SDR-1000 antenna input (using the internal clock) I only get a reading of -2.3 dBm. This is with the preamp off. According to my calculations, it should be reading somewhere around +8 dBm. Anyone have any suggestions on the problem? Bob, K5KDN ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
[Flexradio] SDR-1000 Frequency Stability and Phase Noise Tests
I used the holidays to do a set of tests of the SDR-1000's frequency stability and phase noise (I got temporary access to an Agilent phase noise measurement system to make those possible. I was able to measure the frequency offset, warmup drift, and frequency-vs.-temperature performance of the SDR-1000 with its stock oscillator. I also did a similar set of tests of a prototype Reflock-II frequency stabilizer locking a 100MHz low-jitter oscillator to a 10MHz TCXO. I'm not particularly happy with the phase noise results; due to time constraints we didn't have a chance to properly design the interface and I think there are some external factors that make the numbers look worse than they are. I hope I'll get a chance to play with the phase noise box again and get some better results. But there's still a useful comparison of the noise of the standard 200MHz oscillator versus an external 10MHz reference multiplied by 20; you can really see how the phase noise is increased by multiplication. Anyway, the results are at http://www.febo.com/geekworks/sdr1k. 73, John
Re: [Flexradio] Frequency calibration etc
ecellison wrote: Ross Well, I think we are a ways away from a kit. I was sort of suggesting that we try just using the Rockwell - Jupiter board and it's 10 mhz oscillator 'naked' and just see what we get. In 2 lengthy arounds on this thread mostly what we have is theory and nothing tried at this point. I think that John - N8UR is the only one I have heard about who is using an external 10 mhz reference to the SDR. Comment John? Anyone else using Geralds mod kit with external reference? Results? Yes, I've been using my SDR-1000 with external reference from an HP 5065A Rubidium frequency standard. I haven't noticed any horrid phase noise problems from the 10MHz to 200MHz multiplication, but I also haven't been looking very hard for them. I hope that fairly soon -- perhaps over the Xmas holidays -- I will get temporary access to HP's latest super-duper phase noise measurement box, and one of the tests will be to compare the SDR-1000 with original crystal versus the external reference. I'll certainly post those results when I have them. 73, John
Re: [Flexradio] Frequency calibration etc
Mike King - KM0T wrote: I too have been using an external 10 MHz source on my SDR. First I used a Rubidium source off of ebay, never noticed anything different from the internal crystal other than no drift. (rock solid) Note that I have only used it on 902 thru 24 GHz - where the SDR is the 28 MHz IF. I recently switched the 10 MHz source to the HP Z3801 GPS receiver. I A/B switched the Rubidium and Z3801A back and forth and could tell no difference in the audio. However when I used the waterfall display while doing the switching, the Rubidium source show a bit of light white noise on the screen (where I adjusted it) as the waterfall was moving (it was very slight). The 10 MHz Z3801A source seemed to eliminate this. I am not experiencing anything drastic that would indicate the improper reception or weak signals covered up while using these 10 MHz sources, but I have no way to measure phase noise, just a gut feel for how my system is operating on the UHF/SHF bands. The small rubidiums aren't known for low phase noise (and some of them actually impose FM on the signal), so you might see an improvement when using the Z3801A which has a very low phase noise crystal. That might explain the difference you saw. Any electrically steered oscillator is subject to increased phase noise from noise on the steering signal, but the Z3801A seems to be pretty good. John
Re: [Flexradio] Frequency calibration etc
Well, you motivated me to do a simple test. I'm using the Baudline signal analysis program under Linux and clocking the sound card at (nominal) 96ksamples/second. I am currently injecting a 100mv p-p signal at 11.025kHz (to simulate the SDR-1000 IF output) into one channel of my Delta 44 card. The signal is coming from an HP 3325A synthesizer locked to an HP 5065A Rubidium standard. I'm using Baudline to decimate and downconvert the signal to get a few Hz spread across the screen (decimate by 2048, with an FFT size of 4096). Baudline has a high-precision frequency measurement function that has the potential of uHz resolution (it uses phase measurements rather than just FFT bins). Bottom line -- when I started the test half an hour ago, the nominal 11,025Hz signal showed as 11,024.33235 and right now, it shows as 11,024.33228. While that doesn't say anything about the long term stability, it's consistent with what I've observed over a year or more with this card; frequencies consistently read a little bit low, but never by more than a fraction of a Hertz. Now, this card is in a computer that's powered up 7x24 and has been running for months, so it's in an electrically and thermally stable environment. Results from a cold start might be different. 73, John ecellison said the following on 11/22/2005 05:16 PM: John Thanks for the input. I have not heard of anyone else using the external reference, and you never noted any severe adverse effects. Is the 5065a keeping the SDR dead on, which is the primary objective in this whole discussion. Do you notice variation due to the Sound card clock? Perhaps all the theory we have been gumming about is not that important in practice. If you have to measure the difference on a high quality counter.. er well. Also thanks in advance for the tests. Thanks! -Original Message- From: John Ackermann N8UR [mailto:[EMAIL PROTECTED] Sent: Tuesday, November 22, 2005 8:35 AM To: ecellison Cc: 'Ross'; FlexRadio@flex-radio.biz Subject: Re: [Flexradio] Frequency calibration etc ecellison wrote: Ross Well, I think we are a ways away from a kit. I was sort of suggesting that we try just using the Rockwell - Jupiter board and it's 10 mhz oscillator 'naked' and just see what we get. In 2 lengthy arounds on this thread mostly what we have is theory and nothing tried at this point. I think that John - N8UR is the only one I have heard about who is using an external 10 mhz reference to the SDR. Comment John? Anyone else using Geralds mod kit with external reference? Results? Yes, I've been using my SDR-1000 with external reference from an HP 5065A Rubidium frequency standard. I haven't noticed any horrid phase noise problems from the 10MHz to 200MHz multiplication, but I also haven't been looking very hard for them. I hope that fairly soon -- perhaps over the Xmas holidays -- I will get temporary access to HP's latest super-duper phase noise measurement box, and one of the tests will be to compare the SDR-1000 with original crystal versus the external reference. I'll certainly post those results when I have them. 73, John
Re: [Flexradio] Frequency stability and calibration
[EMAIL PROTECTED] said the following on 11/22/2005 08:29 PM: Also a comment about the Rubidium, Cesium and Crystal oscillators. Oscillators are characterized by short term(phase noise) and long term(drift) freq stability. The phase noise it what concerns us most when it comes to receiving. We want it low enough so that it doesn't swamp weak signals. Ideally it should be 10db below the noise floor of the receiver so as to not reduce sensitivity and hence dynamic range. It is the 'Q' of the resonant component(s) that determine the phase noise. The quartz crystal is still the leader when it comes phase noise. Rubidium and Cesium are superior in time keeping (long term stability), but have awful phase noise. These are the 'real' atomic clocks. The navy is the largest user of these. No GPS under water! Regarding GPS, its timing is based on the Cesium clocks. Being slightly insane, I gathered up the published stability and phase noise specs for a bunch of oscillators and synthesizers and put them in a single table at http://www.febo.com/time-freq/hardware/specs.html. The HP 5065A Rb, for example, has phase noise of -93dBc at 1Hz, and -140 at 1kHz. The 5061A Cs with normal tube is only -82dBc at 1Hz but is also -140 at 1kHz. The 10811A crystal ranges (depending on model) from -95 to -103dBc at 1Hz, and -145 to -162 at 1kHz. The small Rbs like the Efratom bricks that are available on eBay, on the other hand, are pretty horrible as they use FM modulation as part of the loop detection. Of course, the problem is that in the SDR-1000 we are multiplying the 10MHz external reference to 200 MHz, and that multiplication is going to multiply the phase noise as well. The question is whether a low jitter can oscillator at 200 MHz is better than a really good crystal (or even Rb) at 10MHz, multiplied by 20. I hope to do some measurements over Christmas to answer that question. 73, John
Re: [Flexradio] Frequency stability
Hi Eric -- Yes, the Reflock II is now shipping as a kit, though it requires fairly fine-pitch SMD soldering. We'll have an assembled and tested version available as soon as we can get the contract manufacturer lined up. I've done some tests of the Reflock II using a GPS 1pps steering an eBay surplus TCXO, and the performance is quite good. It's not the equal of a more sophisticated GPS disciplined oscillator like the surplus Z3801A, but it holds within parts in 10e9 (e.g., about +/-25Hz at 10GHz). The only downside is that the frequency error isn't a slow ramp, but rather looks like noise with a peak-to-peak period of a few seconds. At HF or even multiplied up to VHF, that's not going to be noticeable. But it bugs me, and we're working to see if there's a way to fix it. NOTE: I haven't measured to see if this effect occurs when using an oscillator, rather than GPS, as the reference. I strongly suspect that you won't see this when locking to an oscillator, because the loop design is very different in that case. TAPR is planning to offer a daughterboard to go along with the Reflock II that will provide a good quality 10MHz oscillator to serve as the reference, and a low jitter VCXO running at 100MHz to drive the SDR-1000. You'll be able to bypass the 10MHz oscillator and use your own, or use GPS, if you'd like. I'm not certain just when the daughterboard will be available, but I know that Steve Bible, N7HPR, has been working on it. (By the way -- the same daughterboard, with a different VCXO, will also drive the Matt Ettus USRP software radio board.) 73, John ecellison said the following on 11/20/2005 06:24 AM: We have gone around in circles a number of times on this subject and it is still on my 'project mentoring' list of things to design collectivly. Depending on how much we have to spend, the best bet looks like TAPR Reflock 2 which has finally been offered as a kit for about $110 and can be slaved to GPS or a high accuracy 10 mhz TC(VC?)XO and produce accurate 100 - 250 mhz standard avoiding the phase shift by multiplying up from 10 mhz. We have not hashed this out lately. http://www.tapr.org/kits_reflock_ii.html?PHPSESSID=f42b43a04fcded6a42ced6193 4840545 Perhaps John N8UR can comment on a complete design using the Reflock-2, and 1 pps GPS.
Re: [Flexradio] Frequency stability
Hi Eric -- The frequency wander seems to be the result of the Reflock II steering step size. Since Luis hasn't yet published the VHDL code that drives the Reflock, we're only guessing, but it appears that the noise occurs when the frequency is around the midpoint between two steering steps. The result is that the output bounces between the upper and lower steps. I suspect this because sometimes the thing will quiet way down and have an order of magnitude better stability, then it will start wobbling again. If this is what's happening, it should be possible to modify the code or the hardware to improve this characteristic. The GPS signal does wander around somewhat, and on top of that the receivers all contribute their own noise in the 50-100ns range. That's why you need to average the GPS signal over quite a time period (1000 seconds or more) to get really good results. However, for use at HF or VHF you can get away with shorter averaging times. Again, we don't know quite what is in Luis' code, but I suspect he's averaging over 60 seconds or so. 73, John ecellison said the following on 11/20/2005 09:44 AM: John Thanks! The daughterboard sounds ideal for what a lot of us want for the SDR-1000. Is the frequency error you mentioned possibly due to the introduced small error in the GPS timebases? I know that in the QST article (can't remember the name) that there was a cyclic and random error from the satellites. Although I seem to recall that it was temperature changes in the shack where he was testing. If it's predictable, probably can be eliminated in software. I really like the fact that it has an I2C interface, since there are a few of us just getting started with the Cyclone FPGA in the Xylo board. One of the ideas was to use an NCO but with I2C we can talk with the Refloc II on the same bus, and the Reflock II is a jewel in the center of the crown of getting really accurate with the SDR-1000! http://www.fpga4fun.com/board_Xylo.html I included Steve, Tim and Tom in another message, since they were major contributors in the first discussions. I think this go around should produce the ideas to glue it all together into a working device. I'm a little shaky on the fine pitch stuff myself and may wait to order the Reflock until you have an assembled kit. Thanks to you and Steve and others for this fine production from TAPR. Gess you can sit back and relax now that someone else is in the saddle! (smile) Fat chance! Eric2 -Original Message- From: John Ackermann N8UR [mailto:[EMAIL PROTECTED] Sent: Sunday, November 20, 2005 9:10 AM To: ecellison Cc: 'Guy Atkins'; FlexRadio@flex-radio.biz; Steven Bible Subject: Re: [Flexradio] Frequency stability Hi Eric -- Yes, the Reflock II is now shipping as a kit, though it requires fairly fine-pitch SMD soldering. We'll have an assembled and tested version available as soon as we can get the contract manufacturer lined up. I've done some tests of the Reflock II using a GPS 1pps steering an eBay surplus TCXO, and the performance is quite good. It's not the equal of a more sophisticated GPS disciplined oscillator like the surplus Z3801A, but it holds within parts in 10e9 (e.g., about +/-25Hz at 10GHz). The only downside is that the frequency error isn't a slow ramp, but rather looks like noise with a peak-to-peak period of a few seconds. At HF or even multiplied up to VHF, that's not going to be noticeable. But it bugs me, and we're working to see if there's a way to fix it. NOTE: I haven't measured to see if this effect occurs when using an oscillator, rather than GPS, as the reference. I strongly suspect that you won't see this when locking to an oscillator, because the loop design is very different in that case. TAPR is planning to offer a daughterboard to go along with the Reflock II that will provide a good quality 10MHz oscillator to serve as the reference, and a low jitter VCXO running at 100MHz to drive the SDR-1000. You'll be able to bypass the 10MHz oscillator and use your own, or use GPS, if you'd like. I'm not certain just when the daughterboard will be available, but I know that Steve Bible, N7HPR, has been working on it. (By the way -- the same daughterboard, with a different VCXO, will also drive the Matt Ettus USRP software radio board.) 73, John ecellison said the following on 11/20/2005 06:24 AM: We have gone around in circles a number of times on this subject and it is still on my 'project mentoring' list of things to design collectivly. Depending on how much we have to spend, the best bet looks like TAPR Reflock 2 which has finally been offered as a kit for about $110 and can be slaved to GPS or a high accuracy 10 mhz TC(VC?)XO and produce accurate 100 - 250 mhz standard avoiding the phase shift by multiplying up from 10 mhz. We have not hashed this out lately. http://www.tapr.org/kits_reflock_ii.html?PHPSESSID
Re: [Flexradio] Slightly Off-Topic
Gary Schmidt W5ZL wrote: Bottom line, I *WILL* buy Linksys products in the future. Drifting things even further off-topic. another reason to support Linksys is that many of their products (in particular, the ubiquitous WRT-54G wireless router) run Linux, and the source code for virtually all the firmware is available. Because of that, several folks have come up with new firmware for the WRT-54G that ranges from enhanced versions of the standard Linksys code, to completely independent Linux distributions. I'm running two WRT-54G units with the OpenWrt firmware, and while I haven't done any of these goofy things with them (yet), it's cool to know that I could run a web or ftp server, hook up a weather station or webcam, run VoIP, or do who knows what else on these little $69 boxes. They even work as access points. :-) John
Re: [Flexradio] Well written article about SDR importance
Eric Wachsmann - FlexRadio wrote: It has been brought to my attention that our own Dr. Frank Brickle (AB2KT) has written an article describing why SDR technology is important. It is an easy read, and is well written with clear points for even the technology challenged. Well done Frank. http://www.groklaw.net/article.php?story=20050916105216639 Superb article, Frank! I follow Groklaw closely and saw the original article that inspired Frank's post; I wondered if anyone would follow up on it. I gave the idea some thought, but I'm glad I procrastinated because Frank did a far better job than I could have. 73, John
Re: [Flexradio] Ext. Reference clock kit
Tim Ellison wrote: Reflock II info: http://gref.cfn.ist.utl.pt/cupido/reflock.html Cost is going to be near $1000 http://www.tapr.org/products.php You caught us... the Reflock II is going to fund the next TAPR board retreat in the Bahamas. :-) Actually, the prices are placeholders because we don't have them quite finalized yet (and we haven't officially announced availability); in particular, we don't have a final quote from the assembly house for the partially assembled and fully assembled versions. The Reflock has one fine pitch IC that's beyond what most hobbyists will be willing to tackle, so we'll be offering bare board only, complete kit with the IC soldered down, and assembled and tested versions. Think more in the $100-200 range (low end of that for the kit, higher end for assembled and tested). John
[Flexradio] Another 1.3.13 CW datapoint
I was playing this morning and discovered something that I don't think I saw mentioned here before. First, like others have reported, the old keyer in 1.3.13 seems to be broken. It keys, but there's no power output. So, I was playing with the new keyer. I found that after sending perhaps 6 dahs at 25wpm, the power output suddenly dropped to near zero. The High SWR indicator did not come on. My unit has the antenna tuner installed, and when I used the control to bypass the tuner, the power drop went away and I could send for as long as I wanted with the power output holding up. (I was testing on 10M, where my vertical has a 2:1 SWR without the tuner.) So, add the ATU as another possible factor in the CW problems... 73, John
Re: [Flexradio] Frequency Accuracy
ecellison wrote: However, there is so much going on in the SDR-1000 and PowerSDR software world there are too many projects all at once! It may take till the end of the year to get a lot done on this. I am gathering hardware and looking forward to the Reflock 2, but would like to see it run native at 200 mhz to supply to the SDR. Could also use a DDS at 200 mhz, corrected at 200 mhz. Will need some USB glue pieces to get it all together with the project that Phil - VK6APH and others are working on. I should have reported this earlier, sorry -- in theory, the Reflock II should work at 200MHz without any problems; of course we'll need to find a decent 200MHz VCXO for it to drive. John
Re: [Flexradio] Frequency Accuracy
Jim Lux wrote: So this uses the SDR1000 as a audio frequency generator, right? The Delta 44's not in the picture at this point, or if it is, it's basically digitizing and playing back at the same sample rate. Hi Jim -- I'm not sure I follow. If the soundcard is not clocking at the rate the DSP software assumes it is, the software's understanding about what frequency it's dealing with will be off by that error. Think about the extreme case -- the soundcard is sampling at 24ksamples, while the software processing the bitstream thinks the sample rate is 48ksamples (forget about underrun problems for the moment). That's going to result in a 1kHz input being presented to the DSP layer as a 2kHz signal. That will result in all sorts of possible errors as the signal is downconverted and otherwise processed. (Remember, there is a digital downconversion in the DSP layer; the input to the soundcard is the IF at 11.025kHz). We're talking about much smaller errors here (maybe parts in 10e5), but the impact is the same -- an error in sample rate will cause the DSP code to think the frequency is slightly different than it actually is, and that will result in an erroneous output signal. The fact that we're using the same soundcard (and therefore the same clock) for both sampling and playback complicates the picture, but since the playback frequency is digitally mixed down from the input frequency, the two operations aren't likely to cancel each other out because the error will scale across that 20 to one frequency range. Or am I missing something? I'm not a DSP (or for that matter, any kind of) engineer, so I'm sure I haven't used the right terminology, but hopefully you can understand what I'm trying to say. John
Re: [Flexradio] Frequency Accuracy
Jim Lux wrote: Consider two RF carriers, at 10.001 and 10.002 MHz If the DDS is perfect, at 10 MHz, and the sampler is perfect, at, say, 10 kHz, then you'll get two sine waves in the digitized sequence. One at 10 samples per cycle (the 1kHz audio) and the other at 5 samples per cycle (the 2 kHz audio). The ratio between the two will be 1:2 If the DDS is off, but the sampler is perfect, then, both RF frequencies will be shifted by the same amount. Say the DDS is at 9.999 MHz (a kHz low). the two audio frequencies will be 2 and 3 kHz, instead of 1 and 2 kHz, so your sampled data stream will have a 5 samples/cycle (the 2 kHz) and a 3.33 samples/cycle (the 3 kHz). The ratio is nolonger 1:2 but something else (5:3.33) If the DDS is perfect, but the sampler is slow (say at 9kHz, instead of 10 kHz), then you'll get two signals at 1 and 2 kHz, but the sampled data stream will have a tone at 9 samples/cycle and one at 4.5 samples/cycle. The ratio is 1:2, but the actual value is different. The effect is the same as the difference between playing a tape fast or slow (which preserves the harmonic relations, even if the pitch changes) and tuning high or low with SSB (which does not). And this is where I'm confused. I'm not (for this experiment) looking at the linearity of the passband, but rather the absolute accuracy of the frequency transformation. The change in pitch is what I'm measuring -- if everything is perfect, I know that an input precisely on the frequency the radio is tuned to will yield an output (audio tone) that's precisely 600Hz. If the sampling rate is off, the 600Hz tone will be off, which translates into a frequency error -- if the tone is 599Hz, that's the same as the radio being tuned 1Hz low in frequency. That's the frequency error I'm trying to measure. John
[Flexradio] Mic Audio settings
After a bit of repair and upgrading at Flex-Radio Central, I just fired up my radio (with amp and tuner) today, and actually talked to someone on 20 SSB! I'm using a D44 card without an external mic preamp, and at the moment just a cruddy hand mike I had around that happened to be wired to work with the front panel mic connector. I know a month or so ago there was conversation about using the D44 without a preamp on the mic input. I found that by setting the preamp gain on the TX panel to about 35, I get what seems to be decent audio. But I'm not sure how that interacts with the Mic setting on the main panel, and I'm not sure how to set the various levels to optimize the transmit audio (not looking for hi-fi right now, just proper levels and a bit of compression to add some punch). Any suggestions for how to optimize the TX audio chain, and particularly how to balance between preamp setting and front-panel Mic gain settings? Any hints on compressor/compandor setting would also be appreciated. (I'm running beta 1.3.12). Thanks, John
Re: [Flexradio] Frequency Calibration.
[EMAIL PROTECTED] wrote: The current cal scheme is unlikely to ever work well for most users. The issue is the error in the oscillator in everyone's sound card. Without taking this into account, most of us can achieve very good accuracy at one WWV frequency but will find it is way off on another. My sound card was several hundred Hz off (at 24 MHz). Unlike the DDS error correction, it does not scale with tuned frequency. I think this is on Bob's list of things to look at. Mike W3IP I'm not sure I follow why the sound card error would result in accurate results at one RF frequency but not another. Error in the sound card clock is like an error in the last local oscillator -- it generates a constant offset that doesn't change with frequency. For what it's worth, the clock in the Delta 44 card (at least mine) seems to be very good. I have used a Delta 44 to drive a spectrum analyzer program under Linux for the last three ARRL frequency measuring tests, and I do frequency comparisons (between a pilot frequency and the unknown signal) with milliHertz resolution. While I haven't done phase noise tests, I've measured a precise reference tone, and the frequency accuracy over periods of tens of seconds to tens of minutes is very good -- at 1kHz, down in the 0.00x Hz range (i.e., parts in 10e-6, about what you'd expect from a good quality crystal). Since that's a direct offset that's not multiplied, the sound card's contribution to the RF frequency error is pretty minimal. Despite those results, my goal is still to have the whole frequency chain stabilized. One thing I've thought about is hardware hacking the Delta to use an external clock. I haven't dug into that possibility yet. Several of the other M-Audio allow an external word clock which the pro audio world uses to lock the sampling rates of multiple cards. It's a shame that feature isn't on the Delta 44 as it would allow an easy way to use an external reference. John
