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What's with the DPRB?

Discussion in 'Electronic Design' started by Jim Thompson, Feb 2, 2008.

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  1. Jim Thompson

    Jim Thompson Guest

    What's with the DPRB? ("Democratic People's Republic of Berkeley")

    It would solve lots of problems if we simply gave California back to
    Mexico before they Californicate the whole nation.

    ...Jim Thompson
     
  2. Guest

    Alternatively, one might give Arizona and Texas back to the Mexicans.
    If Jim and Dubbya are to be taken as representative of their states,
    this is a gesture that would probably double the average IQ of the
    residual United States, when compared with the average that included
    these two states.

    We are talking about seriously negative IQs here - a near anti-genius
    capacity for mis-analyisig a situation and coming to the worst
    possible conclusion. Invading Irak was probably a worse idea than
    giving California back the the Mexicans, but both are spectacularly
    idiotic.
     
  3. Rich Webb

    Rich Webb Guest

    Only if they'll also take Texas.
     
  4. Jim Thompson

    Jim Thompson Guest

    What's wrong with Texas?

    My only complaint about Texas is that the people are so friendly that
    you can't get thru a check-out line quickly due to everyone chatting
    and striking up new acquaintances ;-)

    ...Jim Thompson
     
  5. Nah, just send the Bushists/Cheneyists to Iraq, Afghanistan, Pakistan,
    and so on, so that they can participate in the invasion(s) they all seem
    to be so fond of.

    Thanks,
    Rich
     
  6. John Larkin

    John Larkin Guest

    It's the Bum's Republic of Berkeley now. It's gotten so bad on
    Telegraph Street that people are staying away and shops are closing.

    Leftism is self-limiting!
    We just had lunch on Castro Street in San Francisco. There was a
    vigorous confrontation, a Hillary group facing down an Obama group,
    jamming the sidewalk corner and waving signs in one another's faces.
    No serious injuries.

    They've repainted the Castro Theater, an art deco gem, to look like it
    did in the late 70's. They're filming a movie on the street, about
    Harvey Milk and the assassinations.



    Hey, a new box:

    ftp://66.117.156.8/P730.jpg

    ftp://66.117.156.8/P730.gif

    It's a logic fanout. Two electrical inputs, two optical inputs, 8
    outputs in two banks of 4, with routing and adjustable levels all
    around. We're hoping to run at 1 GHz.

    John
     
  7. neat,how many layers?
    Did you do the layout?


    martin
     
  8. John Larkin

    John Larkin Guest

    Six. The circuitry is pretty simple. All the fast stuff is on layer 1,
    and the miscellaneous signals are on 6. Ground is 2. The other layers
    are all power pours.
    Three of us worked on the pcb layout. I did the fast stuff... still
    tweaking it in fact. My cad guy did the basic board setup and the
    pours (he's great at pours) and will do the formal release and
    gerbers. One of my engineers designed and layed out the power supplies
    on the right. Another one of my guys worked out the optical receiver
    stuff.

    My production manager is also a great mechanical designer. We looked
    around for standard boxes, but nothing was right, so he designed this
    to be custom fabbed from sheet metal. It will be cheaper than a
    standard enclosure, which seems silly. The pic is from SolidWorks.

    The front and back will have polycarb label/overlays. Nowadays they're
    digital printed in unlimited colors (not screened) and laser cut (not
    steel rule die) so we can go crazy on graphics.

    The next spin, once we get this to work, will dump the switches and
    trimpots for a uP with dacs, and add time trims per output.

    The goofy looking run upper-left is an impedance test trace. I'll TDR
    it on a bare board to see how things came out. The two square SMA's
    are for experimenting with plane impedances and noise, just for fun.

    John
     
  9. JeffM

    JeffM Guest

    Yeah. That *egalitarianism* thing is so 1972
    and that Utilitarian Rule is so unworkable.
    You almost quoted the sage.
    "All the war-propaganda, all the screaming and lies and hatred,
    comes invariably from people who are not fighting."
    --George Orwell
     
  10. Thanks, can I ask what the 2 versions of Lombard Street are, going to
    S2, S3, timing would be my first guess


    martin
     
  11. John Larkin

    John Larkin Guest

    Trying to equalize prop delays. This is better:

    ftp://66.117.156.8/P730_16.gif

    It's almost done. Tweaking trace lengths gets tiring after a while.

    John
     
  12. Winfield

    Winfield Guest

    It's hard to see what's going on, with all
    those horizontal lines in your .gif image.
     
  13. John Larkin

    John Larkin Guest

    Those are unreal/artifact slits in the power pours that let you sort
    of see how the layers are arranged. I think they're colorful.
    Actually, the gif resolution is just about good enough to figure out
    what we're doing.

    Show us one of your boards.

    John
     
  14. OK, something simple, a pcb with an Analog
    Devices DDS to 16 outputs (via relays) for a
    Smithsonian Observatory gravity experiment.
    ftp://ftp.rowland.org/pub/hill/pics/RIS-564_pcb.gif
    This was designed before I discovered the
    appeal of mounting parts on both sides of
    the pcb.
     
  15. Here is a piece of junk I made



    I always have a piece of stip board with a zif socket for an 8051
    around, this one still works after 10 years


    martin
     
  16. Joerg

    Joerg Guest


    Hey, why is nobody using rounded traces anymore? I mean, CAD can do that
    automatically these days.
     
  17. John Larkin

    John Larkin Guest

    Interesting. I always like to see other peoples' styles and stuff. The
    Christmas Tree primary color scheme is a bit startling; we prefer
    tasteful pastels.

    Are the RY things relays? We use "K".

    We try to avoid putting a lot of parts on the bottom, but often it's
    unavoidable. Having all the bottom parts be the same value, ie
    bypasses, isn't too bad. We haven't done bga's on both sides, but I
    have seen it done. Shudder.


    Hey, we just got one of the newish Stanford Research clock generators,
    the 2 GHz thing. It looks pretty good, and we got the prbs option to
    test our fanout boxes. What's really unusual is that their instrument
    manuals come with complete schematics and BOMs, and a component-level
    theory of operation. The schematics are nicely commented with design
    notes and explanations. You don't see that much any more.

    John
     
  18. John Larkin

    John Larkin Guest

    Looks Victorian. Soooo last millenium.

    John
     
  19. Joerg

    Joerg Guest

    But in high-G environments you have to ;-)
     
  20. Joerg

    Joerg Guest

    K for kontactor?

    The best I've seen was V for transistors. That was really retro.

    I've used some of their stuff in the Bay Area. What really surprised me
    was that their prices were not sky-high, in fact they were quite modest.
     
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