A more aggressive front end filter migth eliminate the noise substantially. The ubitx front end is wide open. While tuned to 21 Mhz, it? can overload from a 100 khz noise from an smps.?
The bitx40, being a monobander had the luxury of a triple tuned front end. You could add something similar and see if the noise drops.
On Fri, Oct 8, 2021, 2:12 PM Tom, wb6b <wb6b@...> wrote:
On Thu, Oct 7, 2021 at 12:20 PM, Rafael Pinto [PU1OWL] wrote:
Where I live, the QRM level is absurdly high, and my antenna options are very limited.
That's what I really liked about WSPR. With the little uBitx chugging along I could see my signal showing up in places like Antarctica. It was really cool to look at my little transmitter and think the little bit of RF I was generating here was having an effect in an piece of wire so far away.?
Receive wise, not so good. The QRM level here really cut down on what I could receive.
I wonder if switching power supply, LED lamps, smart phone chargers and such have a different noise characteristic than the more natural noise that modulation techniques have been optimized, for better signal to noise performance. I wonder if there any modulation modes that would have better receive performance with this unnatural noise we are now inundated?with?
