Re: [Flexradio] Linux jDttSP
Hi Frank, Frank Brickle wrote: One of the things we're eager to find out is whether running the system entirely from ram disk will iron out some of the glitches associated still with using jsdr on a totally vanilla OS configuration, that is, with no low-latency patches, not running jack as root, and so on. This is very much what I am after. On the EPIA mini-atx, I am using an IDE-CF adapter with a 1GB CF card replacing the HD. Last weekend I have installed the base Debian Linux on it. I want to load a RAM disk kernel image from a diferent partition on the CF. For preserving data, I will try using a tiny raw partition on the CF and do direct I/O on the raw device. This would prevent any filesystem-related overhead. I will post the results on the reflector. 73, -- Edson
Re: [Flexradio] Receiver dies 2 min after power-up, ideas?
I can confirm Eric's statement. One of our three SDR-1000 systems had this problem. Cooling down the AD9854 helped temporarily. Then I installed a bigger heatsink that worked a couple of weeks until the synthesizer got damaged so badly that it did not work any more with any version of the PowerSDR software. Amazingly though, with one of our own small test program it still worked. However, for fully functional tasks of the PowerSDR the chip had to be replaced. For locating the malfunction, perhaps my private message earlier to Wayne may help if anybody else happens to have this same problem: -- Wayne, This is just an educated guess. Try to measure the quadrature DDS signals at U1B pin 6 and U1A pin 7. If no square wave signals present, use cold spray for cooling AD9854. If that brings the signals back, you should know the problem. Use the cold spray very selectively to one component at the time, because the overheating problem may be also on the less expensive components. -- Good luck, if you decide to repair the radio yourself. Safer method may be what Eric suggests. 73, Ahti OH2RZ - Original Message - From: Eric Wachsmann - FlexRadio [EMAIL PROTECTED] To: 'Wayne Roth' [EMAIL PROTECTED]; FlexRadio@flex-radio.biz Sent: Friday, September 30, 2005 11:30 PM Subject: Re: [Flexradio] Receiver dies 2 min after power-up, ideas? This is exactly what it looks like when/if the DDS quits running. Contact us directly about getting the unit serviced. You might look through the various ECOs on the private downloadp age if your unit is not up to date. Eric Wachsmann FlexRadio Systems -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] radio.biz] On Behalf Of Wayne Roth Sent: Friday, September 30, 2005 1:57 PM To: FlexRadio@flex-radio.biz Subject: [Flexradio] Receiver dies 2 min after power-up, ideas? My SDR-1000 (an older rev box with RFE, no PA or tuner, parallel port interface) receives fine for the first couple of minutes then goes deaf. Cycling the DC power restores the receiver for another couple minutes, then it dies again. Just before it craps out, the baseline as viewed on the spectral display raises from -130 to about -70 a couple times along with an increase in the white noise, then drops to -140. All frequencies appear to be dead. Restarting the software has no effect, so it's a hardware issue. I have yet to open the enclosure and get the scope out, just wondering if anyone has seen this, or has a suggestion on where to start looking. Best Regards, Wayne WA2N / 5 Austin Tx ___ 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] Receiver dies 2 min after power-up, ideas?
Tony KB9YIG had a similar dropout last year and prepared this webpage to show how he soldered jumpers around what might have been a poorly soldered plug/socket problem: http://www.n9vv.com/SDR-1000-KB9YIG-GND.html perhaps Wayne's solution is this simple? de Ken Ahti Aintila wrote: I can confirm Eric's statement. One of our three SDR-1000 systems had this problem. Cooling down the AD9854 helped temporarily.
Re: [Flexradio] Receiver dies 2 min after power-up, ideas?
At 06:09 AM 10/1/2005, Ahti Aintila wrote: I can confirm Eric's statement. One of our three SDR-1000 systems had this problem. Cooling down the AD9854 helped temporarily. Then I installed a bigger heatsink that worked a couple of weeks until the synthesizer got damaged so badly that it did not work any more with any version of the PowerSDR software. Amazingly though, with one of our own small test program it still worked. However, for fully functional tasks of the PowerSDR the chip had to be replaced. Thermal damage that results in a partial failure? This brings up an interesting question. Is there some sort of simple diagnostic program or process that could be used to determine if this has occurred? Did you do any sort of failure analysis on the part that was removed? 73, Ahti OH2RZ 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] Receiver dies 2 min after power-up, ideas?
Looking at the picture a few of the crappy solder joints on my PIO board were located at those pins on the header that Tony jumpered around. I read about the heat problem with the DDS chip in an old forum message and did some probing around when I first had the dropout problem. It indicated that there was some problem on the PIO board and not a problem with the DDS chip, but every time I put any mechanical stress on the PIO board the problem would disappear. That is why I just started resoldering all the bad suspect looking solder joints on the PIO board. After running almost continuously for 3+ months I have not had any more problems since I resoldered those joints... I would STRONGLY encourage you to inspect the solder joints on the boards before suspecting the DDS chip, especially if your SDR-1000 has the heatsink already on the DDS chip. 73 de Phil N8VB On 10/1/05, Ken N9VV [EMAIL PROTECTED] wrote: Tony KB9YIG had a similar dropout last year and prepared this webpage to show how he soldered jumpers around what might have been a poorly soldered plug/socket problem: http://www.n9vv.com/SDR-1000-KB9YIG-GND.html perhaps Wayne's solution is this simple? de Ken Ahti Aintila wrote: I can confirm Eric's statement. One of our three SDR-1000 systems had this problem. Cooling down the AD9854 helped temporarily. ___ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz -- Philip A Covington http://www.philcovington.com
Re: [Flexradio] Receiver dies 2 min after power-up, ideas?
Tony jumpered where he did, I jumpered the 5 volt output (directly from the leg of the 7805) to the pin in the header where it was carried off the PIO board. I believed the traces were too small and I had damaged them when changing over from pre-RFE to post-RFE.(3 board to 4 board stack). It is extremely easy to damage the pads. Tony's approach to combining the analog and digital grounds of the DDS is okay. The ECO on the web site uses plate throughs on the bottom of the TRX board. I preferred this because it still allowed easy disassembly of the stack. This was really needed while we were still in the let's hack some hardware mode of the first two years. After we completed the full understanding of the RX-TX transient (using the 0 dB INA gain always when changing state), and then the changes in the RFE front end, I view it as very unlikely for me to change this hardware again and Tony's more permanent fix is a good alternative. The DDS's really want these little overclocker's heat sinks on them. Bob Philip Covington wrote: Looking at the picture a few of the crappy solder joints on my PIO board were located at those pins on the header that Tony jumpered around. I read about the heat problem with the DDS chip in an old forum message and did some probing around when I first had the dropout problem. It indicated that there was some problem on the PIO board and not a problem with the DDS chip, but every time I put any mechanical stress on the PIO board the problem would disappear. That is why I just started resoldering all the bad suspect looking solder joints on the PIO board. After running almost continuously for 3+ months I have not had any more problems since I resoldered those joints... I would STRONGLY encourage you to inspect the solder joints on the boards before suspecting the DDS chip, especially if your SDR-1000 has the heatsink already on the DDS chip. 73 de Phil N8VB
Re: [Flexradio] Receiver dies 2 min after power-up, ideas?
Jim, I agree, this was really a very strange failure in our case. We found out that the circuit did not function with our test program if the sinc and multiply options were included. When we removed those functions from the control program, both I and Q signal were present. We also noticed that the total current consumption was considerably lower. Unfortunately I did not make any notes, but if I remember it correctly it was slightly above 500 mA. After a lot of measurements, optical inspections, mechanical stressing (twisting, shocking, vibration) I am pretty much convinced that it was the failure of AD9854. Unfortunately I have no possibilities of etching the package open for microscopic inspection of the bare die. 73, Ahti OH2RZ - Original Message - From: Jim Lux [EMAIL PROTECTED] To: Ahti Aintila [EMAIL PROTECTED]; [EMAIL PROTECTED]; FlexRadio@flex-radio.biz Sent: Saturday, October 01, 2005 5:07 PM Subject: Re: [Flexradio] Receiver dies 2 min after power-up, ideas? At 06:09 AM 10/1/2005, Ahti Aintila wrote: I can confirm Eric's statement. One of our three SDR-1000 systems had this problem. Cooling down the AD9854 helped temporarily. Then I installed a bigger heatsink that worked a couple of weeks until the synthesizer got damaged so badly that it did not work any more with any version of the PowerSDR software. Amazingly though, with one of our own small test program it still worked. However, for fully functional tasks of the PowerSDR the chip had to be replaced. Thermal damage that results in a partial failure? This brings up an interesting question. Is there some sort of simple diagnostic program or process that could be used to determine if this has occurred? Did you do any sort of failure analysis on the part that was removed? 73, Ahti OH2RZ James Lux, P.E. Spacecraft Radio Frequency Subsystems Group Flight Communications Systems Section Jet Propulsion Laboratory, Mail Stop 161-213 4800 Oak Grove Drive Pasadena CA 91109 tel: (818)354-2075 fax: (818)393-6875
[Flexradio] SDR-1000 Power Out
When using the internal 100 watt amplifier, what is the maximum power output that can safely be set for CW, RTTY or PSK-31? John, AI6A
