HP 8642A Signal Generator 1050MHz repair teardown

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  • เผยแพร่เมื่อ 17 พ.ย. 2024

ความคิดเห็น • 17

  • @Edisson.
    @Edisson. ปีที่แล้ว +6

    Hi Thomas, this is almost top condition, I have always been fascinated by the perfection of the execution. I can't even imagine what kind of knowledge is needed to create these devices, when I saw these in the research lab for the first time, I couldn't even set them up properly and just the idea that someone could create this scared me 😁. I used to own an HP 8903 audio analyzer and it took me more than half a year to bring it back to life, but I've probably aged ten years with it 😂 I love these devices and thanks for showing me, it's a bit nostalgic for me, congrats to such an amazing catch of measuring technique.
    Nice day 🙂 Tom

  • @stevefoster2700
    @stevefoster2700 7 หลายเดือนก่อน +1

    Thanks for this Thomas! I just picked one up. The fan wasn't working so I replaced it. I do see clipping on the top of the output at lower frequencies and it increases with amplitude. By 5000Hz it is good. Perhaps a thermal issue happed before the fan was replaced. Any thoughts on this?

  • @MarkStahlman
    @MarkStahlman ปีที่แล้ว +2

    According to the 1989 HP Test & Measurement Catalog, the Synthesized Signal Generator was meant for "the most demanding out-of-channel RF receiver measurements," and the 1GHz 8642A listed for $24,050, while the 2GHz 8642B listed for $33,050, plus another $2,100 for the "High stability time base." "On-site repair kits" listed for $20,500 and $27,000 respectively . . . !!.

    • @TeardownOZ2CPU
      @TeardownOZ2CPU  ปีที่แล้ว +1

      wow thanks it is quite easy to use online inflation calculator to make this value into todays money :-)

  • @cajuncoinhunter
    @cajuncoinhunter 8 หลายเดือนก่อน +2

    I'm not familiar with the 8642 , I've used the 8656 years ago ...... Does the 42 do what the 56 can do but at higher frequencies ? Modulation is not shown on the display in any pictures I have seen and you have the only video on the 42 on YT ....

    • @TeardownOZ2CPU
      @TeardownOZ2CPU  8 หลายเดือนก่อน +1

      not exactly the same front layout too, minor conmetic differences but they both do AM and FM

  • @markocebokli6565
    @markocebokli6565 ปีที่แล้ว +2

    I think you should look into those power up test failure messages. The "unlocked" one probably explains why you are measuring 102MHz. Even a non-precision master oscillator would be orders of magnitude better than 2% off.
    I have a HP8672 with options to cover 10MHz...26GHz, and when I got it, the "unlocked"" light was on. I could fix that by just adjusting the trimpots on the YIG driver board, the procedure is in the manual. I guess yours is probably not YIG based, but maybe a similarly simple solution exists.
    It would be a pity for such an exquisite generator not to function properly.

    • @TeardownOZ2CPU
      @TeardownOZ2CPU  ปีที่แล้ว +1

      exactly the unit will under go a much more detailed trim and check,

  • @sarahjrandomnumbers
    @sarahjrandomnumbers 7 หลายเดือนก่อน +1

    And some wondered why I went for the Marconi 2024 instead 🤣🤣.
    Lighter, cheaper, easier to fix.

  • @SinnerSince1962
    @SinnerSince1962 ปีที่แล้ว +2

    Wish I could find one

  • @jeffm2787
    @jeffm2787 ปีที่แล้ว +2

    I have one of these, reminds me I need to fire it up. Been a few years. Worked the last time I used it, so....

    • @TeardownOZ2CPU
      @TeardownOZ2CPU  ปีที่แล้ว +1

      it worked last time i tested it.. is a line i heard many times when purchasing defective instruments.. just saying :-)

    • @jeffm2787
      @jeffm2787 ปีที่แล้ว +1

      @@TeardownOZ2CPU LOL, yes I agree. Might pop a cap or two having not been powered up for a few years.

  • @inse001
    @inse001 ปีที่แล้ว +2

    I wish I hadn’t gained weight since 1985 as well

  • @swake0019
    @swake0019 ปีที่แล้ว +2

    If it is a blown cap or similar it should be possible to locate it by smell. ps: I'm a bit shocked about you writing on that power supply PCB .

    • @TeardownOZ2CPU
      @TeardownOZ2CPU  ปีที่แล้ว +2

      writing on pcb is very good to do in case of lack of silkscreen the information is very helpfull during my debug test and repair, i normally leave it, so future people can be happy to save time and trouble in case some one else need to repair it again.