Re: QMX(+) Build experience, Poor Audio Filter Sweep/RF Filter Sweep/Image Sweep/ADC IQ test and resolution with new PCM1804
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To be clear again: I'm saying 15% of the batch of 1000 QMX+ Rev 2 PCBs was rejected during our testing here. The percentage of Rev 2 QMX+ with faulty PCM1804 that reach actual kit builders should be near zero.?
QDX is a similar story. We test for it here.?
QMX is the outstanding problem. We will find a solution to that too.?
So in other words, QDX and QMX+ are purely my own internal problem now. Issues for the kit constructor should be very rare. QMX is still an issue I'm working on and needs to join QDX and QMX+.?
73 Hans G0UPL
Yes, remarkable that the PCM1804 saga continues. I built 4 QMX and one QMX+. Only one had an 1804 failure. First Rev 1 and Rev 3 (mini) had/have no failures. Second Rev 1 had SMPS (5V), then Mplx chip failures. Both replaced and all well. Rev 4 had 1804 failure - replaced and all is well. In fact, that is my go-to mid-band rig for portable operations. QMX+ no problems. In addition, 2 QDXs before had no issues with the 1804s. Both QDXs sold since I have the QMXs.?
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73, Dan? NM3A
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