SDR UNO Diversity Demonstration and feature request
HTML-код
- Опубликовано: 18 сен 2024
- This video shows how well a SDRdou using SDRUno software cancels a phase and amplitude coherent signal. It then moves on to show the excellent results obtainable with real world antennas
Man, I’m digging your shack setup. That’s sweet to have a BNC patch panel, labeled, rack mounted freq generator, etc. Very, very, cool.
Thanks Kevin !!! W1VLF
HamTube's mad scientists finally reveals his lair! You are a great instructor. I've never seen this done this way before. I like your channel.
Thanks for watching!
Great video, tnx for sharing!! I've been experimenting quite a long time with noise cancellation. Found that a Miniwhip active antenna close to the noise source gives me the best result on HF.
Hi Jean-Paul... that is correct for best cancellation you really want a "quality" noise source as you say. No sense in adding extra noise with noise antenna.. Only the one you are trying to cancel W1VLF
Great video, Paul. Have you tried the approach to null out noise? Use one antenna for capturing the signal, and perhaps a smaller antenna to sense local noise (fluorescent light, sub-par LED, switching power supply, etc.), and adjust the phase and amplitude from the sense antenna to null, or at least reduce, the noise? This demo makes me want to get a dual-channel coherent SDR. Thanks again and 73. Ken -- WBØOCV
Great idea
Hi Paul, missed this one when you first released it - nice job.
Thinking about the phase jumping, this is *most* worrying...
I have to assume that the two front-end tuners are operating coherently, otherwise stable diversity could never work. So there ought be another explanation and it's worth contacting Jon Hudson to tease this one out? Suspicion could understandably fall on the phasing control?
Your point about the polar control system is spot on! Although quite intuitive, I suggest in practice it's horrid, especially when co-channel digging for a much weaker station - ideally a pair of horizontal sliders with adjustable sensitivity?
Perhaps this will be addressed in the new SDRconnect software that is supposed to have extensive interface improvements.
Kind regards.
Hmmmm, guess there could be other reasons for the "phase" glitch. Front ends are maybe phase-coherent, but what about gain or attenuation? Could AGC have anything to do with it?
I'd be terrified feeding the siggen output directly into the front end of the receiver. One slip, the wrong power setting, and you've damaged or destroyed your SDR. Would it maybe be better to put attenuators in line for safety? I dunno, maybe I'm the kind of person who puts "warning hot beverage" on coffee cups...
Good experiment. I should have bought the dual channel model like you...
Hello... The maximum power of the RF generator is +7 DBM.. The input level to the RX was -50 a little over 20 over S9... so I was safe. But you are right one must be very careful with an RF generator into an RX. I worked in the ARRL doing lab testing of RX's transmitters etc so I am very cautious about what I feed into my RXs
Why does it have to be set manually at all? The software could do it perfectly itself in seconds and it could even adjust on the fly. No need to fiddle with knobs.
Why does it change when you unplug and replug when using the generator.. Should be same level and 180 phase.. Not??
It should... However I think something in Uno unlocks and the phase relationship is destroyed and so goes the cancellation... That is jus a guess though perhaps someone else can explain