Thanks Gerald for explanation. But for is certain riddle, if perpetrator RFI including RFI getting into the FireWire cable, why sound MONI always clean herewith?
O.K. Possible I also experiment at nearest days. In my shack of no problem with sound TX F5k on this time. "New" transceiver on table and my friend deliver for a while other transceiver, having distortions TX audio. We must compare this and certainly I report result of this test. 73! -- Sergey RW3PS > Dear Flexers, > We want to thank Jeff for all his contributions in support of open source > PowerSDR software enhancements. Jeff and I have been in direct > communication about his problems and are actively working together toward a > resolution. There have been a number of questions generated from this > thread both on the reflector and directly to us at the factory. Let me take > a moment to state the facts and clear the air of some misconceptions: > 1. We agree that Jeff is experiencing a real distortion problem at his > location, which is easy to hear on the recordings he posted. The > engineering difficulty is that we tested the exact same radio and audio > source file Jeff is using with very different results in our lab and in > W5GI's shack. A test file made prior to shipping the current radio back to > Jeff does not exhibit the same distortion that Jeff is experiencing. We > believe that both Jeff's tests and ours were performed with equal care and > attention to detail. In other words, the radio and audio source are the > same for both tests but in different locations, different results. The > question is why the difference? That is what we are working on together. > 2. Klaus Lohmann, our EU representative, reports a high level > satisfaction from the large German pro audio contingent. Many of these > customers own both SDR-1000s and FLEX-5000s. Klaus informed me this morning > that all distortion issues he has dealt with similar to Jeff's were traced > to RFI getting into the FireWire cable or the PC itself. He says that this > was confirmed at multiple locations both on dummy loads and antennas. He > indicated that the fix was to add ferrites on the FireWire cables and in a > few situations the PC itself was at fault. Some customers were using lower > grade cables than those shipped with the radio. Klaus also told me that one > "problem" radio was simply taken to another FLEX-5000 user's location and > the radio worked perfectly at the second location. I cannot confirm that > this is related to Jeff's problem or to the few others reporting similar > issues in the US. However, it is a theory that might explain the varying > results. Further testing will be required. > 3. Relative to the number of radios now in service, we have had a small > number of customers who have contacted us with similar issues. Almost all > were resolved through the application of correct audio settings. Of the > radios we brought back into the lab for reported distortion, we have found > only two where we were able to reproduce the problem. In one of those we > replaced a bad predriver chip and the other is still in diagnosis. > 4. There have been NO changes to the PA hardware since the FLEX-5000 > began production. Any speculations about changes in the April 2008 time > frame are simply incorrect. > 5. In the July 2008 review of the FLEX-5000A, ARRL Lab measured TX IMD3 > at -34 dBc at 100W, which is considered to be excellent for class AB > amplifiers. > The bottom line is that there is no evidence that there is a widespread > distortion problem in the FLEX-5000. However, there is concrete evidence > both in the US and EU that the problem varies by location with the same > radio hardware. We will get to the bottom of it and will report back when > we have something concrete to report. > Gerald Youngblood, K5SDR > President > FlexRadio Systems > 13091 Pond Springs Rd. #250 > Austin, TX 78729 > Phone: 512-535-4713 > Gerald Youngblood, K5SDR > President > FlexRadio Systems > 13091 Pond Springs Rd. #250 > Austin, TX 78729 > Phone: 512-535-4713 > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Jeff Anderson > Sent: Wednesday, July 09, 2008 11:43 AM > To: Reflector Flex-Radio > Subject: [Flexradio] Thanks for the TX audio help! > Just a quick note of thanks to the reflector... > Although I haven't yet resolved my problem, I'd like to thank everyone on > the reflector for their great responses regarding my TX Audio problem! > You've given me many great suggestions, and I'll be following up with more > experiments over the next days. > And I would like to thank Flex for their help, too. I know that they've > also been putting in a lot of work to try to find the root cause of my > problem, and I very much appreciate their efforts. > Now I need to run some errands, and then...back to the lab! > 73, > - Jeff, k6jca > _______________________________________________ > FlexRadio Systems Mailing List > [email protected] > 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 > [email protected] > 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 [email protected] 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/
