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Hi Dan, I?m not 100% sure, what was the cause in my case, so I can only guess. But I would look at the real obvious stuff: - I?ve shortened some of the display wires and gave them another touch

Maybe you should drag your feet a little bit on this repair until more is understood about root cause and corrective action. JZ

Dan, that may be a little too close for comfort. Ten volt 220uF tantalums are available in the same package size. Stack two? Put one on the PS board, one somewhere else on the 5V

Oh one other question. C107 appears to be readily available but it looks like it is only a 6 V tantalum. That doesn't seem like much headroom on a 5 V bus, does it? -- 73, Dan? NM3A

I am slowly working through troubleshooting. 5V bus reads 450 ohms. Powering 5V bus through external power supply shows 90 mA, which seems reasonable. I want to try to power the 3.3V bus with an

Hi Hans, Is the AGC controlled by the S-meter by any chance? I'm asking because the volume control of the latest FW version seems to go completely unpredictably crazy. CW operation (especially with

I've been messing with electronics for most of my life both professionally and for fun. One rule I was taught early on is that you must always employ a current limiting PSU for any new build.

When you say using a 7809, I am assuming that was not added to the QDX, but rather the power supply or in between the PS and QDX. Bob KG5GTE

I look forward to it. Thank you and I do not have mine yet. Jon

Hans, the QMX kit arrived today just in time for the new firmware! We are ready to go :-) 73 Marcel DM3FAM

Once my next QMX kit comes in I will consider putting up a detailed video on assembly.

Roger that Evan! Yes, an oscilloscope is called for here! JZ

John, A failure of one of the two orthogonal outputs of the Si5351 could explain the symptoms.? He measured 2.5 volts on two of the capacitors.? A total failure would have 2.5 volts on only one of

Dave, If the peaks are at 20 M, and the subsequent low area stays low, you should be able to go with that. You're really interested in a passband at your frequency of interest, and then a

The RF Filter scan is the bandpass filter. If you compress the 20m portion of the bandpass toroid it will lower the band pass a bit. Honestly though, your plot is good enough. -mike/w1mt

Hi all, Just got my QMX finished and on the air. I have just done an RF Filter scan and I am a bit confused by the graph results. The graph looks more like a bandpass filter than a low pass filter.

That's great Chris! Now go hook up an antenna and get on the air! Good Luck!..JZ KJ4A <clansd@...> wrote:

Thanks to all for the inputs. From the articles provided, it appears that the sense of winding does matter and both ends of T507 should be wound in the same direction. That's what I'll do. Hope to do

Hi Hans, Ah sorry, my bad, this has been answered. I received the kit but not the 3-500Z final (only one, I assume, because this is QRP after all...), so haven't yet downloaded the assembly manual.

Jim his email is on QRZ. 73, Bill NZ0T