Loading ...
Sorry, an error occurred while loading the content.

Re: RX ensemble II No output at completion of Local Oscillator and Control section

Expand Messages
  • wa2isc
    ... Hi, again Alan, I don t have ready access to a scope, so I use a conbination of the Freq. counter and the Fluke. Since I was looking for AC (OK, RF), I
    Message 1 of 7 , Dec 13, 2012
    • 0 Attachment
      --- In softrock40@yahoogroups.com, "Alan" <alan4alan@...> wrote:
      >
      >
      > ----- Original Message -----
      > Subject: [softrock40] Re: RX ensemble II No output at completion of Local Oscillator and Control section
      >
      >
      >
      >
      > >
      > > The output on the SI570 shows 1.66 V at 60 Hz and no appearant short to ground.
      >
      > Kevin
      >
      > What do you mean 60Hz?
      > About 1V5 DC is expected. And there should be RF, 3V pk-pk.
      > Have you grounded your instruments to USB ground?
      >
      > > jewelers loop tells me that the solder is OK on all 8 pins (ie, no solder bridges or missed pads. It there a way to test the
      > Si570 in situ?
      >
      > You almost have. It should have an output if it has power.
      > Check voltage on pad 2.
      > Normally 3V, unused but if it is grounded in some way it stops the output.
      >
      > 73 Alan G4ZFQ
      >
      Hi, again Alan,

      I don't have ready access to a 'scope, so I use a conbination of the Freq. counter and the Fluke. Since I was looking for AC (OK, RF), I got the 60 Hz on the circuit. I didn't look at the DC voltage. Now, I show .95 VDC on pad 4, and 0 on pad 2. Pad 2 shows infinite R, so not grounded.

      Yes, I used the USB ground for these measurements. I am lost!

      Thanks for your sage advice
    • Alan
      ... Subject: [softrock40] Re: RX ensemble II No output at completion of Local Oscillator and Control section ... Strange, pad 2 should be about 3V. It has an
      Message 2 of 7 , Dec 13, 2012
      • 0 Attachment
        ----- Original Message -----
        Subject: [softrock40] Re: RX ensemble II No output at completion of Local Oscillator and Control section


        > 0 on pad 2. Pad 2 shows infinite R, so not grounded.
        >

        Strange, pad 2 should be about 3V. It has an internal pull-up. When grounded it stops the output. But it is normally left
        unconnected.
        If it is definitely soldered to the Si570 then the Si570 is faulty.
        That is assuming the Test tab of CFGSR is still showing no error when Get is clicked. No error means the Si570 is talking properly
        to the AVR controller.

        73 Alan G4ZFQ
      • wa2isc
        Alan, Thanks for all the help. My conclusion was that the Si 570 was bad, but as i said, I am a newbie to this whole SDR. Pad 2 is definately showing no
        Message 3 of 7 , Dec 13, 2012
        • 0 Attachment
          Alan,

          Thanks for all the help. My conclusion was that the Si 570 was bad, but as i said, I am a newbie to this whole SDR. Pad 2 is definately showing no voltage, and the test does not return an error. You have confirmed to me that it is the Si 570. I will attempt to replace it ( I have nightmares about desoldering it, but...). Again, thanks for the help.

          73, Kevin

          --- In softrock40@yahoogroups.com, "Alan" <alan4alan@...> wrote:
          >
          >
          > ----- Original Message -----
          > Subject: [softrock40] Re: RX ensemble II No output at completion of Local Oscillator and Control section
          >
          >
          > > 0 on pad 2. Pad 2 shows infinite R, so not grounded.
          > >
          >
          > Strange, pad 2 should be about 3V. It has an internal pull-up. When grounded it stops the output. But it is normally left
          > unconnected.
          > If it is definitely soldered to the Si570 then the Si570 is faulty.
          > That is assuming the Test tab of CFGSR is still showing no error when Get is clicked. No error means the Si570 is talking properly
          > to the AVR controller.
          >
          > 73 Alan G4ZFQ
          >
        Your message has been successfully submitted and would be delivered to recipients shortly.