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Fake news.

So this was a totally self inflicted event, but I blew the PWR_HOLD port on the CPU. I don't particularly like the flex the left part of the control board has when pressing on the left encoder so was

Andre, quite simply because GPT4 is beyond awesome and could be of great assistance in programming SDR Transceivers like the QMX but nobody seems to have understood it's capabilities which is a

Useful for probing short timescale propagation. WSPR needs 2 min, FT8 15 sec.? Sporadic-E often fades very quickly :-(? Tropo is more likely to support WSPR. FT4 as well !?? (might also catch some

If Q507 is being driven linearly then I hope it has good heat sinking. I would have thought that in order to keep the efficiency benefits if class E you'd want to switch the uc pin driving that

Without knowing your lighting conditions no one can say. ? Certainly the base designs run the backlight as ‘hot’ as possible and possibly above the backlight LED ratings in some sets/supply

This is sort of the equivalent of saying "but a DAC can only produce one voltage at a time, how can you reproduce an entire waveform that way?" The magic happens when you do it many thousands of

My totally uninformed guess is that it might come down to being an advantage of the Tayloe mixer used in the QMX over the RF sampling ADC used in the 7300.

Chris, Maybe the QMX is simply better. But I would carry out an extended test simultaneously on one antenna with a splitter. I've done that many times using WSPR. Even then I find results are not

A quality set of coil and pot trimming tools... https://cktools-superstore.co.uk/CK-Precision-Electronics-Trimming-Tool-Set-Of 10-T4857 No connection, just a very satisfied customer.. 73 Mike

Yesterday morning, idly running FT8 on my QMX when there was a CQ from New Caledonia, and ATNO for me. The signal to noise was 0 to -5.? That's from half way round the world!? Tried calling but

An even more simplistic view is that the audio signal is a single wiggly line, what you would see on an oscilloscope.? The subtle changes in that generate the multiple tones of speech, even those of

Sid, Yes, the problem was not addressed, going into long term stability and frequency steps. I put my Progrock to one side, I did not think I had it good enough for a HF RX or TX reference. I used a

As I see it, the main limitation, once you have the computing power, is the lack of linear amplification. If you had a linear amp, you would simply generate the IQ data and amplify it. I may have a

Are there any experiences or thoughts regarding the blue vs. yellow displays? Does the blue appear less bright to the eyes? Any opinions regarding readability with old eyes? *(They both look pretty

A big, big thank you to Hans for a very enjoyable QDX build. Assembly and operations manual were clear and I had no problems with the assembly. QDX worked when first powered. I have made FT8 contacts

The STM32F446 microcontroller has two 12 bit DACs. A DAC output is used to control the amplitude of the transmitter output; it's not done with PWM. The current firmware only uses that to control the

Thanks all for your comments. I decided to solder a 1N4148 diode in parallel to L14. Additionnally I always tune my EFHW antenna with a transmatch fed by a NanoVNA until it's perfectly tuned. And to

Dear Karl, You can add my name to that pool of "lifetime supplies"? I pretty much have them and don't mind sharing.? Pretty soon I will have 200 0805 47jH inductors to add to the Millons of parts I

Hi Jim, Yes. I am using a simple command line in Linux on a RaspberryPi 3+ to sent individual FT8 (and WSPR) messages. I'm not using WSJT-X for this application, so no pull down menu. -Bob? KA5MIZ