No Script, No Fear, All Opinion
RSS icon Home icon
  • EEVblog #341 – Mailbag

    Posted on August 28th, 2012 EEVblog 17 comments


    Mailbag Monday
    Fluke 17B Multimeter unboxing
    http://www.toddfun.com
    PIC Tutorial board
    http://www.gooligum.com.au
    IMPLA 3D Printable material
    http://www.printbl.com
    Analog Multimeter Teardown

    Be Sociable, Share!
     

    16 responses to “EEVblog #341 – Mailbag” RSS icon

    • Printbl.com is the American Supplier, Diamondage.co.nz makes the PLA, Shipping is cheap from NZ for us Aussies

    • reflow soldering the breadboard : probably the plastic will not resist the reflow temp. Plus, the contacts are really well isolated by the plastic, so you need even more heat.

      Another potential problem is the solder flowing up to tthe contacts, but this probably will not happen coz the contacts are some 2mm up.

      • Yes, the plastic would be the concern.
        I’ve seen ones that are flat on the bottom, not raised.

        • All the ones I’ve seen here the contacts go to the bottom of the plastic. If they didn’t put a double-sided foam tape on the bottom, it would be exposed. (The tape covers the contacts, isolating them from the tabletop, and the bottom adhesive is still covered so it doesn’t stick, but if you wanted it to stick, just remove it).

          Though, in the end I don’t think it’s that great an idea. Sure it avoids having to jumper from the header to the breadboard, bit also means that that many columns of contacts are unusable. If you need to add some ICs to the board, they most likely will NOT have a convenient pinout to fit, so they have to be put on the “isolated” part of the breadboard and jumper wires brought over to it, leading to no improvement.

          It does work if you’re only adding a couple of trivial components between the signals, but I see it as limiting the practical use of the breadboard.

        • The most viable option would be a press-fit bread-board, although they do not exist… i think.
          You could make something that comes close, by surrounding the bread-board with regular press-fit connectors (like the pc104 ones), and try to get the same hight.

          anyway.. just a thought :-)
          Great blog Dave.

          Bart from the Netherlands

    • I agree with Worf that soldering the contacts would make the breadboard less useful. You’d have say column 30 as RC5 and column 29 as RC4, but what if you weren’t using those signals, or you don’t want them in those columns? Wires are flexible (sorry for the pun…). Speaking of which, I figure that people who buy the training board will own wirecutters/strippers – and most people already have precut trimmed wires anyway.

      By the way, I’d never seen the transparent plastic breadboards either. I have the boards assembled in China, and they supply most of the components (but not all – I’ve learned some hard lessons about Chinese assembly!). I was surprised when their sample had the transparent breadboard. It works well enough, and I agree it looks cool!

    • One clarification on my PIC training boards – I don’t actually sell PICkit 2 or PICkit 3 (or clone) programmers. I guess maybe I should. It would be more convenient for people to be able to buy everything they need from one place, but I didn’t want to have to deal with warranty returns on something I’m reselling.

      It’s something to think about though – I’d be interested to know what people think is right. I’ve also thought about rolling my own PICkit 2 clone and selling that as part of a bundle…

    • Addressing some of your question:

      1. The reason I send you the DIY passive probe is that when I built it, I don’t have a generator that can generates fast enough rise time to measure the performance of the probe. My function generator generates 4 ns minimum, & my scope measure ~5 ns with the probe. I know that you have an Agilent 811x0A PFANG, which is better than mine. Anyway, I expect 4 ns is just about the limit of the DIY probe. ^_^

      2. The Pomona 3752 BNC Box is selling at AUD40.59 on au.mouser.com.

      3. The long slot hole on the [ProbeEnd] PCB is for shield attachment. When I design the circuit, I was worry about the noise that can pick-up by un-shielded PCB. The bottom layer is already part of the shield, & I reserve the possibility to add-on a metal shield on top of it.

      4. Yes, the bottom layer directly beneath the capacitor is un-float by intention. This is to prevent any un-wanted coupling between the signal part to the ground, which can reduce the bandwidth of the DIY probe.

      • Hello Lai Chi,
        My hobbies involve repairing/using 7000, 11400 and DSA600 series Tek scopes.
        I would very much like to have a full copy of your passive probe design like you provided to Dave.
        Would you consider publishing it for people like myself to “roll our own” copy?

        Tnx and Best Regards,
        Chuck w8dux

    • The price of Fluke 17b in China is around $60 US.

      A friend got me one in a Fluke retail store in Shenzhen. Anyway I think that you got fake probes. Mine are a bit different. Looking forward to a full tear down.

      • Interesting about your probes being different.

        • Hi Dave,

          I am now working on a handheld Pulse Generator to allow me to perform the probe compensation away from the scope. I will give you one when it is done. I am targeting a sub-nanosec rise time performance for the generator. Stay tuned. ^_^

    • You guys got nothing to worry about, I’m a professional.

    1 Trackbacks / Pingbacks

    Leave a reply