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Re: Ensemble II HF Problem

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  • k1tli
    I have been over the soldering and all looks fine. No shorts to ground that should not be there and no shorts to other pins. Pins 3& 6 measure 1.345k to gnd
    Message 1 of 6 , Sep 2, 2012
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      I have been over the soldering and all looks fine. No shorts to ground that should not be there and no shorts to other pins. Pins 3& 6 measure 1.345k to gnd as do pins 11 & 12. Pins 3 to 6 read 20.2 ohms. Could U10 be bad?

      --- In softrock40@yahoogroups.com, "R. R. (Robby) Robson" <rrrobson@...> wrote:
      >
      > There is a grounded via that is very close to pin 3 of U10. It is actually
      > beneath the IC, but excess solder on pin 3 might have made a "whisker"
      > contact with that via, pulling pin 3 to ground.
      >
      > I would go over all the pins of U10 with solder wick and carefully inspect
      > the soldering.
      >
      > On Sun, Sep 2, 2012 at 9:07 AM, k1tli <k1tli@...> wrote:
      >
      > > **
      > >
      > >
      > > Alan,
      > >
      > > I put the jumper back in and here are the results on testing U10:
      > >
      > > Pins 2 & 14 measured 2.5 volts
      > > Pin 16 measured 5.0 volts so the 5 volt rail is intact
      > > Pins 10,11,12,13 all measured in under 100mv
      > > Pins 3,4,5,6 all measured in under 100mv
      > > Pins 7 & 9 also read in the less than 100 mv range
      > >
      > > Thanks for helping
      > > Chuck
      > >
      > >
      > > --- In softrock40@yahoogroups.com, "Alan" <alan4alan@> wrote:
      > > >
      > > >
      > > > ----- Original Message -----
      > > > Subject: [softrock40] Ensemble II HF Problem
      > > >
      > > >
      > > > >I have just completed the Ensemble RXII kit but upon testing the
      > > op-amps I ran into a problem. From the beginning I was using the
      > > > >left hand hole at the "QSD/EN" jumper as a ground reference not
      > > realizing there had to be a jumper to the hole on the right.
      > > > >Everything checked OK until I tried to load the op-amps and look for
      > > the voltage change and there was none. I discovered the
      > > > >jumper issue and proceeded to put a jumper between the holes but then I
      > > lost the 2.5v at the hairpin of R28 and lost the 2.5v on
      > > > >U11. Upon snipping the jumper the 2.5 volts returned.
      > > >
      > > > Chuck,
      > > >
      > > > Do you lose the 5 volts as well?
      > > > But this should have been picked up on the test of U10. Test that again
      > > with the jumper in.
      > > >
      > > > 73 Alan G4ZFQ
      > > >
      > >
      > >
      > >
      >
      >
      >
      > --
      > Cheers,
      > Robby
      >
      > Richard R. (Robby) Robson
      > LTC USA (RET)
      > www.wb5rvz.com
      > www.wb5rvz.org
      > www.rafino.org
      >
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