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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

are you aware that even the 'custom' data field in FT8 can contain NO MORE than 13 characters, including any space characters? and generally such custom data fields are entered manually and

I've been interested in including observations from a weather station (such as air temperature, humidity and air pressure) in the WSPR message as is done with high altitude balloons. I've considered

I did extensive testing of the ProgRock2? reporting the results and starting a thread *ProgRock2 as a GPSDO and an anomaly*** ?in message #101344.? I saw essentially the same thing that did Alan

It's pretty intuitive if you think about what an FM signal looks like in IQ representation, and what an AM signal looks like in IQ representation. You can take any signal in IQ space and determine its