#1190

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  • Опубликовано: 21 окт 2024
  • Episode 1190
    Measure S21 and S11 on an amplifier
    Using NanoVNA: • #576 NANOVNA Measuring...
    Be a Patron: / imsaiguy

Комментарии • 48

  • @Hellhound604
    @Hellhound604 6 месяцев назад +2

    This video brings back so many memories of designing and testing RF amps… noise figure, 1dB compression point, IP3 tests, expensive transistors/MMIC’s that oscillate in the GHz range, all whilst looking at the smallest signal on the very expensive Spectrum Analyzer fully knowing one misstep will blow up the Spectrum analyzer for which there was no money on the budget to repair…. Hey, that was the 80’s in which every RF-related thing was more expensive than your car, and heck, the spectrum analyzer costed more than the engineering directors house!!!!! But still looking at it as the good old days 😂😂😂😂

  • @RideGasGas
    @RideGasGas 2 года назад +4

    Normally I wait till the end of a video to comment, but I have to say I am surprised that the solder joints aren't cleaner on this unit. Miteq makes some really good equipment and while the appearance of these joints doesn't affect the operation, I've seen them do better work.
    I purchased a lot of Miteq equipment over the years and have been to their factory a number of times. I even commissioned Miteq to make a custom Ku band up/down converter for an application we had. Art Faverio was a great guy. As co-founder and president he of course had a very nice office up in the executive area, but also had one down in the labs area where spent most of his time working as one of the guys.
    Miteq is a bit like an East coast HP. They use a lot of their own components in larger assemblies they produce for sale to others.

  • @louiskatzclay
    @louiskatzclay 4 месяца назад

    Mostly these days I watch your videos in order to get ready to build a homebrew radio. I am rather old for starting to do this and I am not yet really ready in my life to get started, maybe I never will be, its in the future. There are a few parts of these videos that seem really helpful. I want to develop some innate sense of what things do,,, maybe seat of the pants, as well as a more technical understanding. But there is also how to test, and set up to test, and what I need. This told me I need to build a second set of attenuators at least in some values.
    I took electronics in about 1974 in high school and when we got to AC I was flummoxed although I passed the course. I knew the rules, some equations, but they were memorized not grokked. Slowly it is starting to make sense.

  • @glenwoofit
    @glenwoofit 2 года назад +4

    I've been testing amplifiers at the radio club as I've lots of cheap Chinese LNA's and it's surprising what you get. Some that look and are cheap are better than some of the more expensive and better build looking amplifiers. I am running DVBS / DVBS-2 so I'm looking for good linearity for a QO-100 and for local links on 437Mhz. Some had shoulders less than 10bd while up to 30db

  • @fredmitchel1236
    @fredmitchel1236 2 года назад +4

    Nice...glad to see an active RF
    I am curious about if the amp has adjustable bias
    What a nice demo of big boy...
    Thanks IMSAI Guy

    • @IMSAIGuy
      @IMSAIGuy  2 года назад +1

      looks like fixed 8V

    • @fredmitchel1236
      @fredmitchel1236 2 года назад

      @@IMSAIGuy
      I looked closer at first I thought there were 4 I/O pins...
      I like the opinion you have of not so a wonderful amp...I have nothing to compare to...
      I thought it had good gain..wide broadband response...and not with the flatness as you said.
      Maybe then they had post filter....and narrowed frequency of interest...
      The soldering looked a little lumpy..
      I might try and see & and look up the RF power transistor ....thanks for showing the close up...
      This looks to be a npn bipolar...biased class A...?
      I wonder if like the general purpose MiniCircuits 300 Mhz to 1.5 GHz broadband amps have a flatter response.....maybe I will go look at prior IMASI Guy posted teachings and go see if you had some other amplifiers being measured. I did watch that nice radio test set you rescued from the dumpster....it's capabilities were outstanding...and it's in great condition. Good job. Motorola had sort of a similar like unverisal radio tester but not nearly as nice nor the resources that HP could design into something..
      Would the Q dc point on the collecto be near 4 Vdc?...without any RF in or maybe impossible to check do to the RF chokes...I can go read...
      Curiosity just has got Fred's cat..
      Thanks IMSAI Guy for making short work and showing off your HP VNA & cal skills..
      Could or would the ripple change in the power band if the RF level input was different....?
      Don't worry about my nativity and I look foward to you next displayed endeavor..

    • @omarakdh-xp4eo
      @omarakdh-xp4eo 7 месяцев назад

      Do you have a design for this circuit? I mean PCB schematic
      Very good

  • @PapasDino
    @PapasDino 2 года назад +4

    The gain figure looked like it really flattened out as it approached the limit of your VNA...is it possible that it's actually designed for a higher frequency of operation above 1.3 GHz? Maybe checking it with your Nano might show that?

    • @mickgibson370
      @mickgibson370 2 года назад

      Even 10 GHz, then the capacitive of the case would be involved!

  • @kurtttttttt
    @kurtttttttt 5 месяцев назад

    a Thru response calibration corrects only for errors in the VNA related to transmission tracking and isolation. I wonder if you would see better measurements if you did a two-port SOLT calibration which would correct for errors in directivity, source match, load match, and reflection tracking

  • @RideGasGas
    @RideGasGas 2 года назад +2

    Curious to know if you tested the amp at higher frequencies to find the cutoff frequency on the top end. Miteq made a lot of equipment that covers higher frequencies than just a gigahertz. The amp might have been designed for S, C, X, or higher bands. I did try to look up the part number but didn't get any hits.

    • @deBug67
      @deBug67 2 года назад +1

      My thoughts as well. It looks like they snowflaked the output so that would indicate that is made for multiple gigs. And also the gain is absolutely flat up to 1.3. Could be a K or X band amp.

  • @pyrokinetikrlz
    @pyrokinetikrlz 2 года назад +3

    looking at the smith chart S11, it seems the amp might be designed for a 75 ohms system.

    • @johnwest7993
      @johnwest7993 Год назад

      My first thought, too. They don't often put that sort of high-end mechanical construction into sloppy RF designs.

  • @WElektronik
    @WElektronik 2 года назад

    senang melihatnya rf amplifier sudah bekerja dengan baik

  • @kennarnett8220
    @kennarnett8220 2 года назад

    Of course you had to take it apart. What is the substrate made from?

  • @wa4aos
    @wa4aos 2 года назад +1

    Good video but, as others have mentioned, more testing at higher freqs could be interesting. Also, I wonder if changing out the amp xsistor might make a difference. Anyway, thanks for the great videos.

    • @IMSAIGuy
      @IMSAIGuy  2 года назад

      yes, swapping the MMIC is the right thing to do, I did that on a cheap Chinese amp and put a good part in it.

  • @joeteejoetee
    @joeteejoetee 2 года назад

    Attenuateors for the Win!

  • @W8ASA
    @W8ASA 2 года назад

    The trace seemed to be flattened at the higher frequency. Might it be good from .5 to over 1 GHz?

  • @galileo_rs
    @galileo_rs 2 года назад

    NanoVNA can control the output power. The feature was introduced a while back with DisLord firmware.

    • @IMSAIGuy
      @IMSAIGuy  2 года назад

      that's good to know. I have dislord on some but on others there is no dislord version.

    • @galileo_rs
      @galileo_rs 2 года назад

      @@IMSAIGuy All H, H4 and LiteVNA from Hugen (the manufacturer) are compatible with his firmware. For the output level: It's not much, 4 levels. Basically it's a mA drive setting for the clock generator used as source.

  • @TheElectronicDilettante
    @TheElectronicDilettante Год назад +1

    I tried to look this device up in the manufactures sales catalog but with no luck. However, I found items similar to this but were under the headings of spacebound and mil spec with one that looked identical to this one, but was describe to be used with cryogenic. Is that why it seemed so unimpressive when you tested it? The company it's from deals in what appears to be ultra high end microwave tech. Do you happen to have any liquid nitrogen? That would be a cool video. Please forgive the inadvertent pun. That was shameful

  • @TechProbe
    @TechProbe 2 года назад +1

    MITEQ is one of microwave, mmWave product manufacturers, a decent and good quality. Now merged with Narda. BTW I can not find it P/N155532 in the web.

    • @pyrokinetikrlz
      @pyrokinetikrlz 2 года назад +1

      yeah, I also tried to search for the datasheet. Maybe it is an old discontinued model?

  • @iz8dwf
    @iz8dwf 2 года назад

    you might want to know also P1dB compression point, while you're at it :)

    • @IMSAIGuy
      @IMSAIGuy  2 года назад

      I did a video on measuring that. Don't know which one

  • @ltlt6117
    @ltlt6117 Год назад

    Hello and thanks for good videos
    I have a question iwant to buy lna module there is some types like 20db gain I know If I put 50mv pp in input I will have a 500mv output but ididnt tested it for 400mv input will I have 4v pp at output on 50 ohm load If not why???

    • @IMSAIGuy
      @IMSAIGuy  Год назад

      seems like I have been asked this question before. is it a homework problem? 20db is power gain not voltage gain

    • @IMSAIGuy
      @IMSAIGuy  Год назад

      oh, it is, you asked about another homework problem. do it again and you get banned. study, don't cheat and ask me.

    • @ltlt6117
      @ltlt6117 Год назад

      @@IMSAIGuy I don't know why you're reaction is like this...
      I just asked a question...

    • @IMSAIGuy
      @IMSAIGuy  Год назад

      @@ltlt6117 you once before asked me to help you with your homework. is this homework?

    • @ltlt6117
      @ltlt6117 Год назад

      @@IMSAIGuy no I'm designing a radar I'm confused with amplifiers I want to get a 5v pp signal from 50mv to increase my dynamic range of radar yes I know with high inputs I'm putting them into cutoff and because my transistor should be ultra low noise and high frequency I can't do anything that I want...
      And I have to find a way to use(( low power transistor)) to get a 5v pp on 50 ohm with some treaks. I tried something and works like ((parallel transistors))an I need to know more ways
      You have good memory too.

  • @chadx8269
    @chadx8269 Год назад

    Shaking the metal cased Amp infront of screen makes me nervous.

  • @chuckcrizer
    @chuckcrizer 2 года назад +1

    Male connectors?

    • @IMSAIGuy
      @IMSAIGuy  2 года назад +1

      yes, it was odd

  • @KD0CAC
    @KD0CAC 2 года назад

    You could save the case , remove the components , send me the board - and I could strip the $.50 worth of gold off the board ;)
    Thanks again

  • @__--JY-Moe--__
    @__--JY-Moe--__ 2 года назад

    it's an amp! what more is there 2 know? U plug it up. it amplifies! now tell us about our attenuation span! ha..ha..