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Robert, did you test also other bands? Looking at your 40 m spectrum the signal outside the SSB chanel is only 15 ... 20 dB below the peak in the channel (around 7.152). Did you check the spectrum

Since I loaded the 1.01.003 fw the sensitivity on 10 seems to have dropped considerably. A loud signal on my 705 is barely readable on the QMX. Not sure why.

Evan, My guess is that this thread is looking at RF amps in general, and how to evaluate the voltages and currents that might blow the finals. Curious, on revisiting that uBitx amp, it looks like a

I rather like the Musk approach to innovating.? The big, establishment space company, United Launce Alliance, tries to get it right the first time, spends twice as much as SpaceX, but takes forever

Hi Adam, Im not sure. I’d have to check and see. I’m done with it for now. I tried to use it today and for some reason 10 meter sensitivity is not as good as it was previously. Not sure why. I

Hello, I was trying to connect a electret mic to qmx, I applied external 3.3volts to mic input and it died, won’t turn on , doesn’t draw any current. Any help would be appreciated. Thank you.

It should not matter. The reverse voltage is less than either value, and the forward current is very short in duration. The 1n4148 is the best choice because of the junction's switching speed. I would

I also built an adapter for mine.? In addition I reworked one of the Retevis mics.? I'll see which works/sounds best, they are kinda comparable in size. 73, Don N2VGU

What settings does the 60-15 have for 40m under the terminal band config?? ?I never use 11m and wonder if I can just fill that slot with the 40m config??

As others have reported, I have lost half of the previous output power on my QMX+ after running the calibration. I am beginning to suspect that I lost one or more of the transistors in the final

Cross-posting here in the hopes of Hans seeing it: /g/QRPLabs/message/141596 Thanks.

I have four QDX's and I've decided to add a 1N4148 across L14 as many other have done here to add some protection against accidental high SWR. Digikey lists several versions, including a 100V 200ma

Allison and others.... To be clear, I brought up this old thread to understand the discussion about the RD16HHF1 being a "16v max" device. I have no interest in the original question from another

I use the ICOM HM-219 hand mic.?? It works great.??? I built an adapter cable to connect the mic's eight pin connector to the QMX input. Drew? N5GU

Question for Hans, Have you seen anything like the spectrum I (and Jim) posted?? During my regular weekly QSO with a friend about 170 miles away, while he was able to copy me and it did not sound

Well if you want a more conservative estimate, then 25% of the working age population have a criminal record too -

I would agree that one by one has produced different results on a few bands, but the band I am struggling with is the first one run.

Jerry, Are we looking at the IRF510-based 50-watt class C amp or the PA of the Q_X series? I believe you have a uBiTx IRF510 simulation that might also be relevant. The output is not the TCVM used in

Do not do calibration in one set. Do it one by one with 5 minutes break in between to let the finals have some time to cool down. 20:38, 24 March 2025, "Azgael via groups.io"

Congratulation Hans, this SSB firmware is a great achievement! Still, I have a problem! I had the a QMX plus rev 2 system working on firmware version 1_01_002, preform a calibration and all looked