#1473

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  • เผยแพร่เมื่อ 26 ส.ค. 2024
  • Episode 1473
    I found this on Aliexpress, claimed to be 800MHz to 6000MHz
    Be a Patron: / imsaiguy

ความคิดเห็น • 62

  • @IMSAIGuy
    @IMSAIGuy  ปีที่แล้ว +1

    I'm doing another video where I solder down the coax.

  • @marcino8318
    @marcino8318 ปีที่แล้ว +5

    those holes are for mounting handle to carry antenna for wideband sniffing.

  • @milesprower6641
    @milesprower6641 ปีที่แล้ว +8

    Try connecting the NanoVNA to a computer via VNA Saver. You can do higher resolution scans and save the graphs as images and insert them into the video directly. Even annotate them.

  • @KG4JYS
    @KG4JYS ปีที่แล้ว +1

    Pretty sure the holes are where you can strap the cable down with a zip tie. I've got a similar antenna that came inside a housing and was attached that way.

  • @fannyjim6094
    @fannyjim6094 4 หลายเดือนก่อน

    Incredibly work!

  • @PlaceholderforBjorn
    @PlaceholderforBjorn ปีที่แล้ว +1

    I've seen on some trading sites that those holes doesn't have any function on the antenna design. But is intended for a mount, like a pistol grip.

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว +1

      ray gun

    • @silverXnoise
      @silverXnoise ปีที่แล้ว

      I assumed it was to zip-tie the cable, although they're spaced a little too wide for that. +1 for ray gun.

  • @khimbittle7705
    @khimbittle7705 ปีที่แล้ว +1

    antennas! not getting bored

  • @zerobow9413
    @zerobow9413 ปีที่แล้ว +2

    FYI the nano VNA has software might look better

  • @cowshittt
    @cowshittt ปีที่แล้ว +3

    Soldering down a coax to the boars should improve the performance. Soldering the cable to the antenna is the missing BALUN .

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว

      probably, it stumped me why it had the big ugly connector. what's the point if you are going to solder it

    • @cowshittt
      @cowshittt ปีที่แล้ว

      @@IMSAIGuy That connector makes no sense.

  • @Electrotech1980
    @Electrotech1980 ปีที่แล้ว

    Keep at it, love your videos. Keep in mind that the Nano VNA is feeding square waves into the antenna and wasn't able to replicate the readings common to your expensive machine.

  • @diemaschinedieviereckigeei2941
    @diemaschinedieviereckigeei2941 ปีที่แล้ว +1

    It would be interesting to see, how efficiently this antenna really performs at the high end of the specified band. The PCB material seems to be standard FR4, which gets increasingly lossy above 1-2 GHz.

  • @TheElectronicDilettante
    @TheElectronicDilettante ปีที่แล้ว +2

    How about opening the insulation and soldering the coax only where it intersects each element? What would be a good functional test? I’ve tried using Vistumbler with various 2.4ghz/5ghz antennae to see the number of access points I can reach with one antenna versus another. Quick note… I vote for the return of story time and IMSAI Dog. Have a good day!

  • @1shARyn3
    @1shARyn3 ปีที่แล้ว +2

    holes as passthru for zipties to hold the transmission line?

  • @byronwatkins2565
    @byronwatkins2565 ปีที่แล้ว +1

    I think the holes are for mounting and zip-tying the cable.

  • @espenlyngaas9502
    @espenlyngaas9502 ปีที่แล้ว

    We're not getting bored!

  • @__--JY-Moe--__
    @__--JY-Moe--__ ปีที่แล้ว

    gramps has got to tell us how everything works! he's the only 1 that can calibrate the machine!
    *the oppositional reluctance dipole antenna* ! never heard of one! I'm sure it works 4 the Union ! good luck Pat.

  • @KossuJahvetti
    @KossuJahvetti 3 หลายเดือนก่อน

    Great video! Is it possible to design "log periodic antenna" for two bands, example 800-900Mhz and 1700-1800Mhz if frequencies between is not in your interest? Aiming of course keep the boom length reasonable with most gain on those two bands.

  • @uni-byte
    @uni-byte ปีที่แล้ว

    The only way the soldered down coax could work is if that buss was connected to the shield. If it was connected to the center conductor that operation would leave you with .. not much.

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว +1

      of course is the ground side
      design: fenix.tecnico.ulisboa.pt/downloadFile/844820067125562/Extended_Abstract.pdf

  • @MrMersh-ts7jl
    @MrMersh-ts7jl ปีที่แล้ว +1

    freshly calibrated machine. I see what you did there. 😂

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว +2

      thanks for reading the fine print! 😎

  • @pbaemedan
    @pbaemedan ปีที่แล้ว

    I have 4 of this type and that I use for EMI pre-compiance testing.

  • @ivolol
    @ivolol ปีที่แล้ว +4

    One IMSAI Guy's journey through aliexpress to find the best antennas in the land!
    Does your NanoVNA have an ability to screen capture into a computer or USB stick or similar?
    I'm not sure if you have a video on it already, but I'd be interested to know why your HP thinks it can get to 15-20 -dB whereas the nano was only reporting around 10.

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว

      I guess you get better numbers when you pay $30,000. Or it might be due to the HP connector attached to ground and helping out

  • @Stevef-sk3jc
    @Stevef-sk3jc 3 หลายเดือนก่อน

    hows it perform, i bet its gain is bad due to the circuit board blockage

  • @chrisscott1547
    @chrisscott1547 ปีที่แล้ว

    I'm not sure why Yagi is in the title - it is certainly not a Yagi - just adds more confusion. It looks a bit like a log periodic, but until we see directivity and front-to-back ratio, perhaps we should categorize it as Just-a-Bunch-of-Dipoles. It would not surprise me if directional performance is very poor and it's a complete fraud. EDIT: (Mark subsequently corrected the title, removing Yagi)

  • @robinbrowne5419
    @robinbrowne5419 ปีที่แล้ว

    More antenna voodoo :-)

  • @knglaser
    @knglaser ปีที่แล้ว

    I would call that a "logperiodic looking object" which does not do what it's supposed to. the elements are on top of each other, no interleaving, not a logperiodic.

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว +1

      did you actually watch the video??

    • @knglaser
      @knglaser ปีที่แล้ว

      @@IMSAIGuy yes, the whole one. perhaps missed some language hints (:

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว +1

      @@knglaser they are not on top of each other, they are staggered and out of phase.

    • @knglaser
      @knglaser ปีที่แล้ว

      @@IMSAIGuy wow, I stared at the end where there was closeups and thought there was copper under each of the silkscreen legs, quite hard to spot that detail

  • @____________________________.x
    @____________________________.x ปีที่แล้ว

    Why is the feed element on the opposite side from say a Yagi?

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว +1

      the shorter wavelength will choose the short dipoles if fed correctly, if fed from the other end then the short wavelengths will find long dipoles and odd things will occur.

  • @nickcaruso
    @nickcaruso ปีที่แล้ว

    What are you doing with these antennas? Inquiring minds want to know!

  • @K1ZEK
    @K1ZEK ปีที่แล้ว

    Boy you have a tough audience. LOL It would be fun putting it in front of a parabloc reflector and using it as a feed! Scanning the sky😮. 73. Leo

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว

      It's a tough crowd and occasional heckler. I will not be scanning the sky as I don't speak Martian. 😎

    • @K1ZEK
      @K1ZEK ปีที่แล้ว +1

      @@IMSAIGuy I have about 8 satellite dishes installed that I poke around the sky with. Hoping to get back to it soon. It's like SWL but higher frequencies. 73 Leo

  • @none_of_your_business
    @none_of_your_business ปีที่แล้ว

    what's the smallest HF antenna that you could have? could you possibly hang one out the window of an apartment?

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว +1

      you can use antennas designed for cars, or put a wire antenna under the eves of the roof, or in the attic. search around, there are thousands of people who have tackled that problem.

  • @darkobul1
    @darkobul1 ปีที่แล้ว

    Can you use vna to analyze transformers ?

  • @jeffreyyoung4104
    @jeffreyyoung4104 ปีที่แล้ว

    What happens if the antenna is fed from the aft end?
    Does it have to be fed from the front, just because the TV antennas were?

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว +1

      it won't work right. the shorter wavelength will choose the short dipoles if fed correctly, if fed from the other end then the short wavelengths will find long dipoles and odd things will occur.

    • @jeffreyyoung4104
      @jeffreyyoung4104 ปีที่แล้ว

      @@IMSAIGuy I never looked at it that way, and that makes a lot of sense now!

  • @Yuehanlad
    @Yuehanlad ปีที่แล้ว

    Log antennas are not 50 ohms, so you need a balun.

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว

      actually the PCB designs are made to operate at 50 ohm and get better than 10dB across the range. There are several papers on line. They are supposed to have a soldered down coax. I will need to take off this silly connector and give it a try

    • @willthecat3861
      @willthecat3861 ปีที่แล้ว

      ​@@IMSAIGuy The balun (and matching) network are etched on the pcb The holes, in the pcb, are part of the matching network... and a possibly for implementing 'opens.' There a similar Chinese design... to the one you show... that uses a conductor backed coplanar waveguide to match.

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว

      fenix.tecnico.ulisboa.pt/downloadFile/844820067125562/Extended_Abstract.pdf

    • @Yuehanlad
      @Yuehanlad ปีที่แล้ว

      @@IMSAIGuy cheers thanks for the link.

    • @cyberyogicowindler2448
      @cyberyogicowindler2448 4 หลายเดือนก่อน

      ​@@willthecat3861 How can the holes have an effect when they are outside the copper plated parts? Or has this PCB really more than 2 layers? (Shining light through most cheap PCB antennas shows that they don't.)

  • @Unpopular_0pinion
    @Unpopular_0pinion ปีที่แล้ว

    Is that an antenna built into a pcb?

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว +2

      yes, it just traces on a PC board

    • @Unpopular_0pinion
      @Unpopular_0pinion ปีที่แล้ว

      @@IMSAIGuy That's lit!

    • @paulsherman51
      @paulsherman51 10 หลายเดือนก่อน

      Wonder if you could put two PC boards together, at 90-degrees to each other, receiving both H and V polarizations? Would they be phased at 0 or 90 or 180?