[Flexradio] Proof-of-concept successful!
This weekend Bill, KD5TFD, completed his integration of our Wolfson A/D + Xylo FPGA + USB interface into PowerSDR. This proof-of-concepth has been completely successful and we are eagerly pushing forward to the next phase of the project. The screen shot below is of our 48k 16 bit full duplex sound card running in PowerSDR using an SDR1000 on 20m http://www.hamsdr.com/dnld.aspx?id=126 The noise floor of the Wolfson A/D in this configuration is -140dBm in a 500z bandwidth. The next steps are to increase the sampling rate to 192kHz and 24 bits. Bill is also going to implement his system to overcome the frequency error and drift of the 200MHz Valpey Fisher oscillator. He is using a GPS 1Hzor 10kHz clock to measure the frequency of the DDS output and pass this back over the same USB signal that carries the digital audio. A software routine in PowerSDR will then compare the actual DDS frequency to the desired frequency and make the necessary correction in software. If this works OK then he will look at counting the 200MHz oscillator directly, although picking this off the SDR1000 hardware is bit more involved than the DDS outputhence the reasonfor starting with the DDS output. We are looking at deriving an LVDS signal from the 200MHz oscillator and if anyone has any suggestions as to suitable connectors to use with a single LVDS signal then we would appreciate the information. There is still plenty of room for more C++ and FPGA developers if you are interested in assisting with the project - those willing to lay out PCB's will be especially welcome! 73's Phil Vk6APH No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 267.14.23/243 - Release Date: 27/01/2006
Re: [Flexradio] Proof-of-concept successful!
At 12:30 AM 1/29/2006, Phil Harman wrote: We are looking at deriving an LVDS signal from the 200MHz oscillator and if anyone has any suggestions as to suitable connectors to use with a single LVDS signal then we would appreciate the information. I assume you're actually talking about a differential pair LVDS signal. IEEE 1394/Firewire uses multiple pairs of LVDS signals at those kinds of rates. SATA (Serial ATA) uses a 7 pin connector to carry a pair of LVDS signals: Gnd, pair A, gnd, pair B, gnd. We use 9 pin Micro-D connectors for 100 Mbps+ SpaceWire signals (4 LVDS pairs). But, they're fragile and expensive. A good quality 100 Mbps ethernet jack and cat5 cable can also do it. The real key is in board layout behind the connector. Jim, W6RMK
[Flexradio] TeamSpeak
I was able to get on Teamspeak for the first time yesterday now that I have FIOS by Verizon. I am unable to put in a nick name or logon name. It give me a logon error. As long as it is blank I'm OK?? I've tried Jerry, jerry, wa2tti, WA2TTI, Jerry Wa2tti nothing works. Jerry
[Flexradio] Frequency
I know this has been beaten to death but I never saw anyone say what they are experiencing. I had a big problem in the beginning it was off by 278kc, after the component change I'm off 200 and drift up to dead on in less than 15 minutes. From the 15 minute mark on I see no drifting. Jerry Wa2tti
Re: [Flexradio] Frequency
At 07:25 AM 1/29/2006, Jerry Harley wrote: I know this has been beaten to death but I never saw anyone say what they are experiencing. I had a big problem in the beginning it was off by 278kc, after the component change I'm off 200 and drift up to dead on in less than 15 minutes. From the 15 minute mark on I see no drifting. Jerry Wa2tti you're a quarter of a Megahertz off? Out of what frequency? Actually, no matter what, that's a huge error. I'd say you have a bad oscillator. ___ 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 James Lux, P.E. Spacecraft Radio Frequency Subsystems Group Flight Communications Systems Section Jet Propulsion Laboratory, Mail Stop 161-213 4800 Oak Grove Drive Pasadena CA 91109 tel: (818)354-2075 fax: (818)393-6875
Re: [Flexradio] TeamSpeak
Jerry There is no Logon name, make sure there is nothing there. Also make sure that you have anonoymous checked. Server Address is 70.84.228.202:9274 Server Password is: Flex4U (case sensitive) Make -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jerry Harley Sent: Sunday, January 29, 2006 10:19 AM To: FlexRadio@flex-radio.biz Subject: [Flexradio] TeamSpeak I was able to get on Teamspeak for the first time yesterday now that I have FIOS by Verizon. I am unable to put in a nick name or logon name. It give me a logon error. As long as it is blank I'm OK?? I've tried Jerry, jerry, wa2tti, WA2TTI, Jerry Wa2tti nothing works. Jerry ___ 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] Frequency
I'd made some measurements on my radio a few weeks ago and came up with a Freq vs. Temp variation of roughly 0.2 ppm/degree F. At 5 MHz (where I'd made the measurement), this works out to roughly a 40 Hz shift for a 40 degree change in temperature. (Only the temperature of the radio itself was changed; the PC was kept at a constant ambient temperature.) I didn't try it from a cold start, though. - Jeff, WA6AHL -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Jerry Harley Sent: Sunday, January 29, 2006 7:26 AM To: FlexRadio@flex-radio.biz Subject: [Flexradio] Frequency I know this has been beaten to death but I never saw anyone say what they are experiencing. I had a big problem in the beginning it was off by 278kc, after the component change I'm off 200 and drift up to dead on in less than 15 minutes. From the 15 minute mark on I see no drifting. Jerry Wa2tti ___ 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] SSB Net
Just a reminder that the SDR-1000 users group still meets on 14.313 MHz at 1900Z every Sunday. Please join us to evaluate your SSB signal, and to pick up tips on your SDR-1000. Hope to see you next weekend. 73, Hank K9LZJ Greenfield, IN http://www.flex-radio.com
Re: [Flexradio] FlexRadio Digest, Vol 9, Issue 29
Hi Robert, Your plate is full. Like I said you take it easy and drive safely. Just a note of interest. The Gates Vanguard is the only transmitter of it's kind. I found out the other day the Vanguard 1 is the same transmitter but it is in a regular 6 foot rack. Interesting! SO if you find yourself pondering a Vanguard and want the small one like mine, Don't Pick the Vanguard 1. Talk to you soon. Over and far out. Mike - Original Message - From: [EMAIL PROTECTED] To: FlexRadio@flex-radio.biz Sent: Sunday, January 29, 2006 1:00 PM Subject: FlexRadio Digest, Vol 9, Issue 29 Send FlexRadio mailing list submissions to FlexRadio@flex-radio.biz To subscribe or unsubscribe via the World Wide Web, visit http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz or, via email, send a message with subject or body 'help' to [EMAIL PROTECTED] You can reach the person managing the list at [EMAIL PROTECTED] When replying, please edit your Subject line so it is more specific than Re: Contents of FlexRadio digest... Today's Topics: 1. Re: Monitoring AM (Willi Reppel) 2. Re: mdb location in compiler (richard allen) 3. Re: HamSDR upload filesize increased to 40 MB (richard allen) 4. Re: mdb location in compiler (FlexRadio - Eric) 5. Re: Monitoring AM (FlexRadio - Eric) 6. Re: Companding, Compression and Equalizer (FlexRadio - Eric) 7. Proof-of-concept successful! (Phil Harman) 8. Re: Proof-of-concept successful! (Jim Lux) 9. TeamSpeak (Jerry Harley) 10. Frequency (Jerry Harley) 11. Re: Frequency (Jim Lux) 12. Re: TeamSpeak (Eric Ellison) 13. Re: Frequency (Jeff Anderson) ___ 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] Frequency
At 09:06 AM 1/29/2006, Jerry Harley wrote: Jim Lux wrote: At 07:25 AM 1/29/2006, Jerry Harley wrote: I know this has been beaten to death but I never saw anyone say what they are experiencing. I had a big problem in the beginning it was off by 278kc, after the component change I'm off 200 and drift up to dead on in less than 15 minutes. From the 15 minute mark on I see no drifting. Jerry Wa2tti you're a quarter of a Megahertz off? Out of what frequency? Actually, no matter what, that's a huge error. I'd say you have a bad oscillator. NO, 200hz off from a cold start and within 15 minutes right on. Ohhh.. I was going from was off by 278kc So you're looking at 200 Hz out of, say, 14 MHz?That's 10-20 ppm, which is within spec for the oscillator, I think. It's not a TCXO on the SDR1000 (TCXOs have better frequency accuracy over temperature, but poorer phase noise, and Gerald picked for performance after warmup). If you're stable after 15 minutes, then you're in great shape. If you need turn on and be accurate within ppm within seconds, you need some sort of other external oscillator. James Lux, P.E. Spacecraft Radio Frequency Subsystems Group Flight Communications Systems Section Jet Propulsion Laboratory, Mail Stop 161-213 4800 Oak Grove Drive Pasadena CA 91109 tel: (818)354-2075 fax: (818)393-6875
Re: [Flexradio] Frequency
At 10:00 AM 1/29/2006, Kurt Vangsness wrote: John, I see similar behavior. From a cold start I'm off freq by hundreds of HZ and after something like 2 to 3 minutes there is a sudden shift and everthing is on freq and relatively stable. I've always been surprised that it is such a sudden shift and not a gradual shift as the osc. warms up. A sudden shift? Are you commanding anything, or is it just sitting there? On my radios, sudden shifts were almost always due to the the temperature of the DDS. If it gets too hot, it stops responding to the commands correctly. Doesn't outright fail, but seems that some bits don't get through. My radios are the older heatsink-less varieties, and even a small air flow (from one of those tiny 1U high 40mm fans) entirely fixes the problem. Jim, W6RMK
[Flexradio] Auto Mute Idiosyncracies
I still have not been able to get the auto mute function to work correctly. When you set up the SDR as receive only and enable the auto mute box on Setup-General-Options page the SDR goes into mute. This is the case when the plug in X2 is disconnected. An ohmmeter reading of X2-12 to ground indicates 60 ohms. If I set up the SDR with PTT disabled on the Setup-General-Options the receiver no longer mutes. Disabling the PTT also disables the auto mute function. Can anyone else verify this? I have tried various combinations of settings but nothing works. The 60 ohm reading seems low to me. Maybe a diode is blown. Any ideas? 73, Dale AA5XE
Re: [Flexradio] Frequency
Hi Jerry, I had a frequency stability problem, not exactly as yours but both may be related. The symptoms was the stations appeared very displaced about 50 % the times I powered up the radio. Meanwhile I was figuring out what was happening with the calibration I discovered that unplugging and conecting again the power connector several times the frequency returned to the right value. After measuring carefully the offset at different frequencies, I supposed that the reference frequency sometimes was starting at 199.2885 MHz, since it was consistent with the measurements. Gerald advised me that the probable cause was the oscillator and it was not not related to the software or the DDS. I ordered a replacement oscillator and received it a week ago. This weekend I installed it and the problem is gone. It seems that those oscillators may develop a failure mode that affects stability. You can do some tests using an external oscillator ( the external oscillator kit may be improvised following the info) or temporarily replacing the suspect module with another with a suitable frequency, since submultiples of 200 Mhz could work. I used a plug in 50 Mhz module recovered from a computer MB because I was nor concerned with the spectral purity, only I wanted to be sure that the oscillator was bad. The circuitry has provisions for single ended or balanced oscillator output and the multiplication ratio can be set in the console setup. I hope this may help. 73 de Ignacio, EB4APL Jerry Harley wrote: I know this has been beaten to death but I never saw anyone say what they are experiencing. I had a big problem in the beginning it was off by 278kc, after the component change I'm off 200 and drift up to dead on in less than 15 minutes. From the 15 minute mark on I see no drifting. Jerry Wa2tti ___ 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] Frequency
Jim, Just sitting there - It always happens and only once, after that everything is stable. My DDS has the heat sink (ECO-ed) so I still suspect it is just an unusual behavior of my oscillator. Kurt KC9FOL Jim Lux wrote: At 10:00 AM 1/29/2006, Kurt Vangsness wrote: John, I see similar behavior. From a cold start I'm off freq by hundreds of HZ and after something like 2 to 3 minutes there is a sudden shift and everthing is on freq and relatively stable. I've always been surprised that it is such a sudden shift and not a gradual shift as the osc. warms up. A sudden shift? Are you commanding anything, or is it just sitting there? On my radios, sudden shifts were almost always due to the the temperature of the DDS. If it gets too hot, it stops responding to the commands correctly. Doesn't outright fail, but seems that some bits don't get through. My radios are the older heatsink-less varieties, and even a small air flow (from one of those tiny 1U high 40mm fans) entirely fixes the problem. Jim, W6RMK
Re: [Flexradio] Proof-of-concept successful!
At 05:47 PM 1/29/2006, [EMAIL PROTECTED] wrote: Jim, Thaks for your input. How does this sound as an idea. We make a litte daughter board that the VF 200MHz oscillator plugs into that also fits the current socket on the SDR1000. We add an LVDS driver to the daughter board but only use one output connected to an SMB connector. At the FPGA we have an SMB connector and use one input of an LVDS receiver terminated in 50 ohms and the other input biased at the correct DC level. I'd rather not use Ethernet hardware if at all possible due to the size of the connectors. No.. LVDS is basically a balanced current loop interface that drives + or - 3 mA through the load (nominally 100 ohms). The LVDS driver is a current source, and the receiver measures the +/- 300mV voltage drop across the load resistor. It is NOT a differential voltage interface, and to try and improvise a single ended interface with LVDS is foolish and ill-advised (because you're throwing away everything good about LVDS). The LVDS driver doesn't necessarily have a constant common mode voltage, for instance (because the LVDS receiver doesn't care). If you want a single ended interface, then use a 50 ohm driver and use coax. Use a transformer if you want galvanic isolation with your coax. If you're not connecting and disconnecting all the time, why not just use a twisted pair and a 2 pin header to send the LVDS? It's not like you're trying to send data with varying bits, just a constant frequency signal. You aren't worried about matching skew or all the other traditional high speed issues, nor do you really care about flat frequency response. Twisted pair is the right characteristic impedance (which is why 100 ohms was chosen for LVDS, by the way), but, you do want to make sure it's not twisted too tight (because that increases the capacitance), and, if you use shielded TP, you want to make sure the capacitance to ground isn't too high. Any of the differential pair connectors used for MIL-1553 or for PECL would also work. Jim
