Testing the decorrelation mode in the new Perseus22 SDR receiver (3): "The Lamp"

Описание к видео Testing the decorrelation mode in the new Perseus22 SDR receiver (3): "The Lamp"

This is a very technical video, testing the decorrelation mode of my new Perseus22 SDR receiver. This time I'm having a fight against "The Lamp", the obnoxious kitchen lamp that I keep always switched off (you can understand why), but my wife sometimes switches on, usually when some interesting DX station is popping up. The Lamp always wins. So far.
As in the previous videos, I've a Wellbrook ALA-1530, a wideband active loop antenna, very good on medium waves, connected to HF1; and a preamplified dipole quite deaf on MW connected to HF2. The loop is at 3 meters from The Lamp, while the dipole 5 to 15 meters from it. The Lamp is an halogen lamp, a real pest QRM-wise. The receiver is tuned to 1503 kHz, where Radio Metropolis broadcasts from Trieste, 200 kilometers from me. It's about 22.00 hours local time in Italy (or 10 p.m. if you prefer), so it's evening in Italy.
In the spectrum window, the black rectangle on the upper side, you can see the high noise level during all the video, while in the waterfall window the yellow-blue lines change with the level of noise: yellow is bad (noise), blue is good.
The video begins with HF1: noise, noise, lots of noise. At 19" I switch to HF2: noise again. At 33" I switch to HF1+HF2; the two input signals are received together: noise again. I'm doing nothing for a while, only highlighting the available commands and the pop-up windows explaining their meaning. Ok, let's roll. At 02' 24" I begin to try some decorrelation, by trial and error. When I switch to "NOISE" the algorithm processes the inputs for a few seconds and gives a result as Rho=0.603, whatever it means. No joy: noise everywhere. At 02' 54" I switch to "SIGNAL" to see what happens; the algorithm says that now Rho is 0.351, but noise keeps on. At 03' 17" I open the bandwidth just to see what happens and switch to "NONE"; hey, for a moment something happens. But let's go back to "NOISE": at 03' 28" the noise begins to disappear! Please look at the spectrum window: the noise is still there, but you can't hear it any more. Let's switch to synchronous AM (AMS) to get some better audio. Can you hear the station now? Let's switch to "SIGNAL": mmm, even better, and Decorrelated Min gives the best result, while the other blending options fail. Now let's try "NONE": no joy until I try "Manual". A coloured wheel and a triangle appear. Let's see what happens when I move them. A few adjustments and bingo!, the noise is gone. The Null/Max box inverts the result, just in case you love listening to noise. You bet, I don't like noise, and at the end of the video you can hear the identification jingle of Radio Metropolis, at last in the clear. "The Lamp" lost its battle against Perseus22.

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