Re: [Flexradio] rfi from the sdr
I doesn't sound like the SDR to me it sounds like a ground loop or common mode at the computer. I would first make sure everything is plugged in at the same place, not going through multiple strips each with its own protection Ground everything to the same point. Isolate things that carry RF like feedlines that includes the line between the amp and the rig as well as between the amp and antenna. This is the basic minimum then I would start adding ferrite and stuff like that. 73 W9OY Be a PS3 game guru. Get your game face on with the latest PS3 news and previews at Yahoo! Games. http://videogames.yahoo.com/platform?platform=120121 ___ 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] rfi from the sdr
I've experience a little rfi. I do not get these problems with my ft1000mp running 1000 watts out of a vl1000 amp. So, I'm pretty sure it's the sdr. Locks the keyboard can but not always, lock PowerSDR. shuts down one of the USB cameras. Fine as long as I stay below 400 watts output. Worse on 17, 12, (haven't tried 10 but bet on it) Well grounded system, same computer as the Yaesu. So before I start with torroids on all the cables, I'd like to do this systematically and if anyone else experienced this situation. So if anyone experienced something similar, and found torroids on FA-66 power cable did the trick. What was the cable, connection, that they found was the culprit. SDR-1000, run on parallel port, FA-66 sound system (using the power supply, not Firewire bus), wireless keyboard and mouse. Yagi and dipole on tower, approx 50 feet above the shack. Which cables should I start on first? - Suppose you were an idiot and suppose you were a member of Congress. But I repeat myself. Mark Twain - Bill H. in Chicagoland webcams at http://76.16.160.118:8080/ weather at http://hhweather.webhop.org ___ 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] rfi from the sdr
Your problem is going to be unique to your setup, so someone else's silver bullet may not help you. You have to use a systematic approach to soling the problem. My best guess is you probably have a high impedance ground loop. Here are just a few things to try... 1.) isolate the audio connections from the SDR-1K to the soundcard using isolation transformers (this is covered in the KB) 2.) Make sure if you have a dedicated ground rod for the shack that it is tied into the AC safety ground using at least 4 gauge solid CU wire. 3.) All AC devices should be on the same AC circuit. Best is if that are all connected to a common device like a line conditioner or a UPS. 4.) If you antenna is not balanced, you need to shunt the RF off of the coax shield before it enters the shack with a low impedance ground (tied into all of the other grounds). Consider using a 1:1 balun to further isolate the antenna shield from the rig. 5.) If you use a bunch of wall warts for AC-DC power, make sure all of them are on a single power strip and this is plugged into the same AC circuit as all of your other AC devices. 6.) Put ferrite beads on ALL connections going into the computer. It is cheap and it can't hurt. 7.) Use good quality, heavily shielded cables. If it was cheap, it is not well shielded. 8.) You can try unplugging cables one at a time from the computer to see which one is the culprit. There is about 20 billon articles on this subject on eham.net in the Elmer's section. That is a good resource to look for ideas. -Tim -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of FireBrick Sent: Thursday, May 31, 2007 4:44 PM To: FlexRadio List Subject: [Flexradio] rfi from the sdr I've experience a little rfi. I do not get these problems with my ft1000mp running 1000 watts out of a vl1000 amp. So, I'm pretty sure it's the sdr. Locks the keyboard can but not always, lock PowerSDR. shuts down one of the USB cameras. Fine as long as I stay below 400 watts output. Worse on 17, 12, (haven't tried 10 but bet on it) Well grounded system, same computer as the Yaesu. So before I start with torroids on all the cables, I'd like to do this systematically and if anyone else experienced this situation. So if anyone experienced something similar, and found torroids on FA-66 power cable did the trick. What was the cable, connection, that they found was the culprit. SDR-1000, run on parallel port, FA-66 sound system (using the power supply, not Firewire bus), wireless keyboard and mouse. Yagi and dipole on tower, approx 50 feet above the shack. Which cables should I start on first? - Suppose you were an idiot and suppose you were a member of Congress. But I repeat myself. Mark Twain - Bill H. in Chicagoland webcams at http://76.16.160.118:8080/ weather at http://hhweather.webhop.org ___ 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] rfi from the sdr
I had a time getting rid of the rfi here. Experienced the same symptoms. Keyboard would go bezerk and at time shut the computer down, sometimes to standby, other times all the way. I use only attic antennas and run only 100W and a good ground is a dream as shack is on the second level. Never the less here are the steps I took and what eventually cured it. 1) All antenna feedline entering the shack is coax. (one feedline from the MFJ remote antenna switch). 2) Isolated all antennas as far from the shack as was pratical, and that helped. 3) Put Radio Shack clamp ferrites everywhere (Questionable benefit as it turned out.) 4) Put a RadioWorks RF Isolator at the MFJ remote antenna switch in the attic. That cured it!!! Stopped it dead in its tracks. Good luck, RFI elimination is trial and error, in my case a lot of trials...Hi Hi 73 Jim W4ATK ___ 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/
