#592

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  • เผยแพร่เมื่อ 11 ธ.ค. 2024

ความคิดเห็น • 37

  • @robertcullipher3492
    @robertcullipher3492 4 ปีที่แล้ว +3

    To check for spurious, make sure to go to the High port and check the multiples of 146. The 3rd and 4th order harmonics for my baofeng and btech HT are horrible, but the LOW port only shows the 2nd order(which is also out of spec)

    • @researchandbuild1751
      @researchandbuild1751 2 ปีที่แล้ว

      People probably overestimate the importance of these specs. The antenna is also going to act like a filter, too. By the way, in have a shortwave radio and i can pick up a couple local AM broadcast stations on their second harmonic. Wirh a sensitive receiver, you will never avoid harmonic issues. The goal is more that your signal will be weak anough that any legit signal on that harmonic would overpower it

    • @johnwest7993
      @johnwest7993 ปีที่แล้ว +1

      Yep. He overlooked the fact that on the LOW input the SA doesn't read above 350 MHz. But here it is 2 years later and for another $35 my TinySA Ultra conveniently uses a single input to read all frequency ranges and has a software feature that automatically reads and displays the levels of pretty much all significant harmonics. Time marches on.

    • @billellis3137
      @billellis3137 ปีที่แล้ว +1

      @@johnwest7993 I noticed that in one of his other videos (can't remember which one, I've watched so many). I think it's the one where he's using the NanoVNA as a signal generator. He was puzzled by the fact he couldn't read above 299 MHz yet he never used the high connection port nor did he switch from low to high input. Hey everybody makes mistakes. tried it with mine, yup that was it. Since it's my first day with ANY SA I thought it was pretty cool I noticed it. I know, I know...don't break your arm patting yourself on the back. 😁

    • @johnwest7993
      @johnwest7993 ปีที่แล้ว

      @@billellis3137, it's always easy for us to analyze after the fact. I use a Harbor Freight $5 multimeter so I don't blow up any of my Flukes doing something stupid. :)

  • @bulldogbrower6732
    @bulldogbrower6732 3 ปีที่แล้ว +1

    Finally somebody who can make that box dance. The company should pay you to demonstrate their product. By the way for modulation just press one of the front panel keys on the Baofeng.

  • @gorba2008
    @gorba2008 4 ปีที่แล้ว +1

    Good morning INSAI Guy! Congratulations on the video of the dynamic test of the load built by you, using NanoVNA and TinySA which are, in my opinion, the latest equipment with excellent cost benefit. Enlightening and inspiring video for those who like to work with RF.

  • @vidasvv
    @vidasvv 4 ปีที่แล้ว +1

    Just a wild guess about the load at 100MHz, could it possibly be picking up local FM broadcast? TNX 4 the upload !
    73 N8AUM

  • @SpinStar1956
    @SpinStar1956 4 ปีที่แล้ว

    OMG! Pretty telling when you have a VNA clamped in a Pana-Vise, while I'm holding this single-triode vacuum tube in my hand!

  • @subramanianr7206
    @subramanianr7206 4 ปีที่แล้ว

    I was little confused about the frequency read out on the top of the display; am I missing something here..!?

  • @JohnUsp
    @JohnUsp ปีที่แล้ว

    You said "dummy load", but I guess you did an "Attenuator" and seems your attenuator is -30dbm, right? I want to test HTs from 0.5W to 10W. How much DB attenuation do you recommend? 30, 40, 50 db? Thanks.

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว

      th-cam.com/video/Sdb_cs13njk/w-d-xo.html

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว

      by the way, it was a dummy load with an RF tap. not an attenuator: th-cam.com/video/4sxPSJKPOs4/w-d-xo.html

  • @subramanianr7206
    @subramanianr7206 4 ปีที่แล้ว

    I mean if it just didn't correlate with the signal injected into the load.

  • @DavidLopez-bz4rj
    @DavidLopez-bz4rj 4 ปีที่แล้ว

    Some Baofeng series suffer from being deaf when connected to external or base antennas. Maybe because they don't reject signals out of band.
    Have you observed anything like this on yours?
    Could a passband filter help with this? Thank you!

    • @IMSAIGuy
      @IMSAIGuy  4 ปีที่แล้ว

      Mine is great. I really like it. I've owned many yeasu and icom HTs and the Baofeng is the best I've had. $25

    • @DavidLopez-bz4rj
      @DavidLopez-bz4rj 4 ปีที่แล้ว

      @@IMSAIGuy Did you tried connecting it to a base antenna? Thank you. The only thing I dont like of them is the digital squelch instead of a knob, besides of that they are great and cheap.

    • @IMSAIGuy
      @IMSAIGuy  4 ปีที่แล้ว

      @@DavidLopez-bz4rj yes 2m j-pole

  • @robertcullipher3492
    @robertcullipher3492 4 ปีที่แล้ว

    Unfortunately, it’s not in spec. 97.307(e) says for that frequency it must be 60db below the fundamental, or 25uW, based on power(so 100 watts needs 60db down, 5 watts needs no more than 25uW) If that is a Baofeng (5W) then you need no more than 25uW, or about -53db. That being said, it’s so close that I doubt anyone will hunt you down for such a close margin.

    • @IMSAIGuy
      @IMSAIGuy  4 ปีที่แล้ว +1

      4.5W does not look great

    • @robertcullipher3492
      @robertcullipher3492 4 ปีที่แล้ว

      @@IMSAIGuy sorry I updated my comment like 4 times during your post.

    • @IMSAIGuy
      @IMSAIGuy  4 ปีที่แล้ว

      I'll blame it on my 27yr old test gear and the TIny was never calibrated so can't trust it.

  • @fernandocano8982
    @fernandocano8982 4 ปีที่แล้ว

    can you check sensitivity of the radio with tiny sa?

    • @IMSAIGuy
      @IMSAIGuy  4 ปีที่แล้ว

      no. sensitivity requires the injection of a signal at very low levels -80dBm to -120dBm and the monitor of the audio output of the radio for distortion.

    • @fernandocano8982
      @fernandocano8982 4 ปีที่แล้ว

      @@IMSAIGuy ok thanks

  • @subramanianr7206
    @subramanianr7206 4 ปีที่แล้ว

    Good morning. Thanks for posting this video on your homebrew RF sniffer with arbitrary attenuation.
    I would rather prefer the term "sniffer" though the cold is connected to that of the dummy load rather than to call it a "tap".
    These thick film Chinese resistors are somewhat good for Amateur radio operators and though they are mentioned to be good upto GHz, I was very much doubting that.
    Here the way you have made the dummy load in a screened box with heat sink is all that anyone can do maximum in taking care to have the shortest leads. All in all its a good demonstration.

  • @marcelomigueldasilva7444
    @marcelomigueldasilva7444 ปีที่แล้ว

    Qual é o melhor dos dois?

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว +1

      depends on your needs,

    • @marcelomigueldasilva7444
      @marcelomigueldasilva7444 ปีที่แล้ว

      ​​@@IMSAIGuycalibrar antena

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว +1

      @@marcelomigueldasilva7444 the nanovna is for testing antennas

    • @marcelomigueldasilva7444
      @marcelomigueldasilva7444 ปีที่แล้ว

      ​@@IMSAIGuyok, obrigado. Más o tinysa não é pra calibrar antena?

    • @IMSAIGuy
      @IMSAIGuy  ปีที่แล้ว +1

      @@marcelomigueldasilva7444 the nanovna is used to test to resonance frequency of the antenna by measuring the VSWR, a TinySA can be used to measure the amount of radiated power from an antenna but not accurately. When I design an antenna I use the nanovna