6
votes
DIY 40m Antenna tuning: RLC and SWR
Excellent that you're using a NanoVNA and measuring complex impedance instead of relying solely on SWR. That's the bare minimum standard for modern antenna discussions. SWR (Standing Wave Ratio) is ...
- 3,971
4
votes
DIY 40m Antenna tuning: RLC and SWR
@lornop, there's a lot to @Ryuji AB1WX answer, and certainly all valid and worth understanding, but just in case some of it is a bit beyond your current understanding, I'll give you a different take; ...
- 1,217
3
votes
Alpha Delta DX-B Antenna Installation
OK SamR, it's very common for folks to mix up DC grounding for static and lightning mitigation, and RF grounding. I think most experienced people will say if you want a DC ground, you can, and should ...
- 1,217
2
votes
DIY 40m Antenna tuning: RLC and SWR
Is the perfect antenna going to be (50+0j) Ω?
That will be the perfectly matched antenna, with the minimum feedline loss. It's not necessarily the perfect antenna. A dummy load is 50+j0 too, and any ...
- 13.4k
2
votes
What causes this "Wedge" in weather Doppler radar imagery?
What causes this? I can imagine it being close-range obstructions, or something with the dish passing over a seam in its mechanical assembly, or something to do with signal processing. Is this a ...
- 18.4k
1
vote
What causes this "Wedge" in weather Doppler radar imagery?
The National Weather Service radar at Taunton, Massachusetts (KBOX) is part of the national NEXRAD / WSR-88D network: an S-band Weather Surveillance Doppler radar built to watch storms continuously. ...
- 3,971
1
vote
Current flow in a coaxial cable
If there is no current on the outside of the coax, then it is indeed true that the current in the center conductor will be 180 deg out-of-phase with that on the inside of the coax shield. Remember, ...
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