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  1. khiggler

    Dredging of silt/sand from Santa Barbara harbor entrance, using some automated method

    Don't know if this is the correct location for this question. The Santa Barbara harbor was located in exactly the wrong place I read years ago. Hence it has a constant silt problem at the inlet/outlet to the harbor. There is now a limit to the size of boat that can enter and exit. The...
  2. khiggler

    4NEC2 Antenna Program: Patch definition and wire connections

    This statement "4nec2 manual says end of wire must terminate in "center" of patch." has to mean "in the center line, but definitely not in the center of the patch". Patch antennas suck if the antenna cable or connector is directly in the center. A patch antenna is simple to make, no...
  3. khiggler

    Visual understanding of EM fields within a rectangular metal container

    This is a large microwave oven problem. The RF energy bounces around if it's an empty container and you get hot and cold spots. If it's a full container the energy will bounce around alot if there is alot of metal inside, and the energy will get absorbed and weakened away from the antenna, and...
  4. khiggler

    Quadrifilar antenna design and interference

    Sounds like a job for an experienced satellite antenna engineer. Those launches are extremely costly. I see trouble brewing. If you don't analyze the antenna positioned X meters from the satellite, you really aren't analyzing the antenna cuz RF is going to bounce off the satellite. Isn't NEC...
  5. khiggler

    Antenna

    The test equipment connects a Wide frequency Signal Generator, Amplifier, antenna, sends energy through the airwaves ... energy arrives at victim. This Energy moves electrons at the victims equipment and causes the victims equipment to malfunction. Usually, victim needs to shield the equipment...
  6. khiggler

    R&S VNA port definition

    They are identical, since the measurements can be S21 and S12, plus S11&S22. I believe they have identical hardware inside them.
  7. khiggler

    VNA measurement

    The extra frequency range is probably related to interference calculations towards other systems 1 MHz his a.m. radio and the spec might want to show it roll off below band
  8. khiggler

    feed methods?

    Feed b) will radiate from the outer jacket of the cable. Hence it will affect your antenna pattern. Feed a) needs a balun to make it work normally.
  9. khiggler

    Aircraft HF antenna vibration in Icing Conditions

    Old aircraft used wire antennas. They must have had the problem. Hydrophobic coatings keep water off surfaces. I wonder if that would prevent ice buildup. On a car antenna, vertical thin posts type antennas, the wire wrapped around it prevents it from oscillating. I wonder if that would work...
  10. khiggler

    Radome to active element separation

    I did have a log periodic detune and change gain by 4 dB (around 500 Mhz) when I contacted it to foam. i.e HH to VV antenna chamber test calibration, VV changed alot when I stuck it into the foam which it was placed atop. Hence if your radome is going to touch a resonant antenna (narrow band...
  11. khiggler

    TE10 Direction and Range Control

    TE 10 just means strong in the middle weak on the edges. If your question is actually can you focus the energy like you would focus a light wave and the answer is yes but you'll need a lens made of dielectric. The wave in general keeps propagating but a Lens could focus it to a hottish point...
  12. khiggler

    dual band antenna

    Bicone or monocone. 45 degree flair angle. Simplest antennas to build.
  13. khiggler

    Dual band discone antenna

    20 mhz discone size needs 1/6 Lambda or 8 foot wires, or a triangular flag, metallized, attached to the discone top. There is no Magic, you need large size. 20-3000Mhz continuous should be the goal. Your needs are too wideband for any tuned device with a magical solution. you could use part of...
  14. khiggler

    Embeddable in-metal RFID

    If you place antennas inside metal, they won't work in general. So antennas inside metal may be a marketing item only. Unless skin depth (look for skin depth calculators vis google) allows some energy into the antenna and the antenna looks like a transformer, as in this...
  15. khiggler

    RFID Antenna Design - Is This Possible?

    RFiD antennas are very specialized antennas and normal antenna size dipole requirements don't work. RFiD antennas are closer to wound transformers than they are dipole antennas. I suggest you attempt to buy RFiD antennas and evaluate how well they work. You need to have a system spec for what...

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