Diversity- Signal or Noise Canceling
Posted: Thu Jul 11, 2019 9:59 am
Very happy to see the diversity capability is now available!
Unfortunately, it seems to be set up for combining signals to improve reception. Actually, I'm not sure about that because the instructions in the manual aren't clear to me and the reference Wikipedia article has left my head spinning. (Please don't tell me I have to be a mathematician or a programmer to use this).
I have been using antenna phasing equipment successfully for years and had heard that phasing two coherent receivers was a better way to go. I've been anxiously awaiting the day when I could try this.
With antenna phasing you adjust the signal amplifiers (one for each antenna) in the phasing unit until the signal strength from both antennas is equal, then adjust the phasing of the signals until they cancel each other out. I'm looking for a way to do this with the RSP Duo and I think I'm getting there. However, it requires a lot of switching back and forth between receivers and every time you do this the Spectrum and Waterfall displays zoom back out as far as they can, which really slows the process down. Surely there must be a way to switch between receivers without having to zoom the display back in every time...or is there a way to do phase cancellation that doesn't require switching between receiver displays. (Note: I only have one receiver on screen at a time.
I'm trying to understand the descriptions in the User manual, Page 78:
1. "This window shows the current phase and amplitude being applied and the automatic values that are being continuously calculated and applied" These automatic values are what? The phase angle and amplitude that give you a "best signal"?
2. "select a phase (indicated by the angle in the circle) and an amplitude (indicated by the length of the line to be applied to the incoming IQ streams" I think I understand the idea here. In my way of thinking I would adjust the phase angle to show 0 (zero) degrees (or 180 degrees, which is where the signals ought to be perfectly out of phase for proper cancellation. However, what am I adjusting with the amplitude control; the amplitude of one of the two signals. If not then I don't know how one would ever be able to cancel (phase out) a strong signal.
Many thanks for any help!
Ken Alexander
So Phisai, Thailand
Unfortunately, it seems to be set up for combining signals to improve reception. Actually, I'm not sure about that because the instructions in the manual aren't clear to me and the reference Wikipedia article has left my head spinning. (Please don't tell me I have to be a mathematician or a programmer to use this).
I have been using antenna phasing equipment successfully for years and had heard that phasing two coherent receivers was a better way to go. I've been anxiously awaiting the day when I could try this.
With antenna phasing you adjust the signal amplifiers (one for each antenna) in the phasing unit until the signal strength from both antennas is equal, then adjust the phasing of the signals until they cancel each other out. I'm looking for a way to do this with the RSP Duo and I think I'm getting there. However, it requires a lot of switching back and forth between receivers and every time you do this the Spectrum and Waterfall displays zoom back out as far as they can, which really slows the process down. Surely there must be a way to switch between receivers without having to zoom the display back in every time...or is there a way to do phase cancellation that doesn't require switching between receiver displays. (Note: I only have one receiver on screen at a time.
I'm trying to understand the descriptions in the User manual, Page 78:
1. "This window shows the current phase and amplitude being applied and the automatic values that are being continuously calculated and applied" These automatic values are what? The phase angle and amplitude that give you a "best signal"?
2. "select a phase (indicated by the angle in the circle) and an amplitude (indicated by the length of the line to be applied to the incoming IQ streams" I think I understand the idea here. In my way of thinking I would adjust the phase angle to show 0 (zero) degrees (or 180 degrees, which is where the signals ought to be perfectly out of phase for proper cancellation. However, what am I adjusting with the amplitude control; the amplitude of one of the two signals. If not then I don't know how one would ever be able to cancel (phase out) a strong signal.
Many thanks for any help!
Ken Alexander
So Phisai, Thailand