Uni-Byte 0234 - Let's check a CLASSIC Fluke 8840A/AF DMM

แชร์
ฝัง
  • เผยแพร่เมื่อ 7 ม.ค. 2025

ความคิดเห็น • 38

  • @TheDefpom
    @TheDefpom หลายเดือนก่อน +2

    I did some repair videos on the 8842, which is almost identical, I kept one unit as I was impressed with how accurate and stable it was, even though it hasn’t been calibrated in decades.

    • @uni-byte
      @uni-byte  หลายเดือนก่อน

      Good to hear. This one was apparently calibrated in 2019, but that is just hearsay as I was not supplied a certificate. What do you do with all the stuff you fix?

    • @TheDefpom
      @TheDefpom หลายเดือนก่อน +2

      @@uni-byte I hoard it, apparently LOL. I do try to sell items I don’t really need, but as NZ pretty small there isn’t a lot of demand for the stuff I work on.

    • @uni-byte
      @uni-byte  หลายเดือนก่อน +1

      @@TheDefpom I tend to hang onto stuff too. Where I am in Canada I'm just about the only person locally that is into electronics. Everything needs to be shipped in and shipped out. Last month I tried to give away about 30 pieces of equipment and could get no one interested. I think they thought I was trying to scam them or something.

    • @johnwest7993
      @johnwest7993 หลายเดือนก่อน +1

      @@uni-byte, I like to tutor people to get their ham licenses. Elmering provides me with a ready-made source of unsuspecting people to give radios and test equipment to. :)

    • @uni-byte
      @uni-byte  หลายเดือนก่อน

      @@johnwest7993 That sounds like a really good way to pass stuff on. I've tried a couple of times to start a community learning class in electronics, but got no takers.

  • @johnwest7993
    @johnwest7993 หลายเดือนก่อน +1

    I have an 8840/AF that I got in exchange for repairing 4 other 8840/AF's. They were sold at a government auction from the USAF repair center. To be blunt, the service techs at the repair center's skill set appeared to consist of the ability to read a repair flow-chart, and little else. The repair tags told embarrassing stories of government employee ineptitude. For instance, one of them had replaced an IC that their repair chart identified as defective. But when the unit still didn't work it went into the surplus sale. I desoldered the IC, turned it around the right way, soldered it back in, and the unit worked once again. So after a day and a half of repair work I was the proud owner of an 8840/AF that has now been on my bench for many years. While it may not be within calibration specs, (like you, I have no idea,) once I had repaired it I notated its values against what passes as references for me, and there has been close to zero change in any of the measured values, (right-hand digit stuff,) over a 15 year time frame. It's just very stable, which provides me with a lot of confidence in it. It's also very close to a used Agilent bench multi-meter I have, and my similar Keithley bench meter. All 3 are very stable over time. So for a hobbyist bench meter the old Fluke more than meets my needs. Thank you for your ongoing video series. I look forward to each of them.

    • @uni-byte
      @uni-byte  หลายเดือนก่อน +1

      Thanks John. I tried working in a government branch here in Canada for a few years in the middle of my IT career. It was close to home and I had to take a large cut in pay to do it. This was an environmental research center where I offered help in IT and mathematics. While my workmates were not incompetent, they more than made up for it in being "under motivated". I had to leave to keep my sanity. I get your story.

  • @arne9219
    @arne9219 หลายเดือนก่อน +1

    Very nice score.
    Those type of meters are confirmed rock solid as we used around 10 of them for almost 30 years in calibration at our R&D lab.
    There was never any need for readjustment but the displays are now completely dimmed.
    The 20V range also have high impedance which is very rare at such a class of instruments.
    Cheers

    • @uni-byte
      @uni-byte  หลายเดือนก่อน

      I do like the high impedance input.

  • @Petro-k4d
    @Petro-k4d หลายเดือนก่อน +1

    I have two of these with the LED kits installed. The kits work well, digits are slightly scaled down from the original but completely readable. What surprised me, and as a few others have mentioned is that the calibrations of these units appears quite stable over such long time frames

    • @uni-byte
      @uni-byte  หลายเดือนก่อน

      Good to hear!

  • @grubboy3514
    @grubboy3514 หลายเดือนก่อน +2

    Nice pick up man! That thing will outlive us all.

    • @uni-byte
      @uni-byte  หลายเดือนก่อน

      It is very well made and should last, and last, and...

  • @grubboy3514
    @grubboy3514 หลายเดือนก่อน +2

    I would trust the Fluke more than I would the Siglent quite frankly. I have 2 independently sourced Fluke 45's and they both agree exactly. A great peice of engineering the Flukes!

    • @uni-byte
      @uni-byte  หลายเดือนก่อน +1

      I'm inclined to agree. This is my 4th Fluke bench DMM and I wouldn't mind some more.

    • @johnwest7993
      @johnwest7993 หลายเดือนก่อน +1

      @@uni-byte, I thought that about Fluke handhelds. Then an old friend passed away and I got his 4 Fluke handhelds to go with my other 2. So now I try not to allow myself to think there might be any more equipment I need.

    • @uni-byte
      @uni-byte  หลายเดือนก่อน +1

      @@johnwest7993 LOL! A pretty little bargain will present itself and you will be helpless!

  • @davidv1289
    @davidv1289 หลายเดือนก่อน +1

    Very nice meter at a great price! The dim display photos on eBay are caused by multiplexed displays and fast shutters. Some times you can get a better idea of display functionality if there are multiple photos.

    • @uni-byte
      @uni-byte  หลายเดือนก่อน

      I agree. HE also told me the display was dim. I guess he used it in a very bright environment.

  • @andymouse
    @andymouse หลายเดือนก่อน +1

    Nice catch !

    • @uni-byte
      @uni-byte  หลายเดือนก่อน +1

      YEs, it is! :)

    • @andymouse
      @andymouse หลายเดือนก่อน +1

      @@uni-byte :)

  • @robharley9838
    @robharley9838 หลายเดือนก่อน +2

    Nice score! The 8840 is a great series of meters. I picked up an 8840A with an AC option a few years back at a Hamfest and it has been a very solid performer for me. I've found it especially impressive using 4 wire Kelvin clips for measuring resistance. I'm curious now what the AF designation means on your meter. Thanks for sharing this! - JRH

    • @uni-byte
      @uni-byte  หลายเดือนก่อน +1

      The "AF" stands for Armed Forces and is the Mil spec model. The enhanced features listed by FLUKE are:
      Meets MIL-T-28800C Type II, Class 3
      Improved and expanded environmental specifications
      Comes with the AC option installed as standard
      Enhanced EMI/RFI protection
      Up to 1000V AC
      DC voltage ratio measurement mode.

    • @robharley9838
      @robharley9838 หลายเดือนก่อน +1

      @@uni-byte Oh Wow, I never would have guessed since it wasn't encased in a steel box with latches :) Really nice find. Enjoying your videos! - JRH

    • @uni-byte
      @uni-byte  หลายเดือนก่อน

      And painted #4B5320. army green for the army and the marines or ASA 61 grey for the air force and the navy. 👍👍

  • @darrenmurphy6251
    @darrenmurphy6251 หลายเดือนก่อน +1

    I bought one with a dim vfd on ebay no so cheap (UK premium) and the same led display covertion kit you showed but I haven't needed it, the vfd perked up perfectly fine with a few days use, just long term storage I guess, also have a solar tron 7150plus but much prefer to use the fluke

    • @uni-byte
      @uni-byte  หลายเดือนก่อน +1

      I've heard things in the UK can be pricey.

  • @ivolol
    @ivolol หลายเดือนก่อน +1

    Volt nuts would say the the SZA263/LTFLU-1 reference used inside those is worth the price of admission alone. You can argue it could possibly rival the stability of the LTZ1000

    • @uni-byte
      @uni-byte  หลายเดือนก่อน

      Yeah, those SZA263/LTFLU VRs sure have a cult following. There is a 21 page tread on them over on the eevblog forum.

  • @percaine
    @percaine หลายเดือนก่อน +2

    Nice fluke dmm. You lucked out to get one for that price.

    • @uni-byte
      @uni-byte  หลายเดือนก่อน

      I agree.

  • @SymbolTech21
    @SymbolTech21 หลายเดือนก่อน +1

    Which camera are you using?

    • @uni-byte
      @uni-byte  หลายเดือนก่อน +1

      Canon EOS R50.

    • @SymbolTech21
      @SymbolTech21 หลายเดือนก่อน +1

      @uni-byte to expensive for my budget

    • @uni-byte
      @uni-byte  หลายเดือนก่อน

      @@SymbolTech21 Not very cheap, but cheaper than a lot of others with similar specifications.