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Re: [AT_Sprint] ATS-3B strange DDS output

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  • sergej kindsvater
    Steve, you re right, I was panicking too early, DDS measured alright at the junction R16/C28. I also now got everything working RX/TX after going with solder
    Message 1 of 3 , Dec 30, 2007
      Steve,
       
      you're right, I was panicking too early, DDS measured alright at the junction R16/C28. 
       
      I also now got everything working RX/TX after going with solder iron over two rows of capacitors and resistors (R15-R18 and C25-C34) that I originally did with the hot air gun. I saw there might have been some solder paste rests left behind the parts. Again, it just confirms your assumption it's all about soldering.
       
      I btw didn't like the hot air method and did most of the board in a conventional way. Even though I purchased a commercial smd reworking station I wasn't able to control the air flow to be gentle enough as to not to blow away the 0603 parts. I also thought I might have burned insides of the DDS chip as I had to re-heat it a couple of times to get placed just right (using hot air method).
       
      But the good thing is the rig is working and is excellent! Just worked SP, YU and IK on 80m with what left of a 9V block battery (7.6V according to the battery voltage readout, i.e. just under 8V), my Power meter was showing about 1W input power.
       
      Steve, many thanks for the excellent design!
       
      Happy New Year everybody!
       
      72 Sergej DF6MU
       
      On 12/29/07, Steven Weber <kd1jv@...> wrote:


      > Hi, while attempting to calibrate the reference oscillator I
      >found that I am measuring 6 MHZ instead of 10 MHz at TP1 and can&#39;t
      >adjust it. LO trim calibration does produce audio okay.

      If the LO trim produces the audio beat note, then the DDS is producing the
      correct frequencies. It could be that your frequency counter isn't
      responding to the TP1 signal properly. Try measuring at the R16/C28
      junction instead.

      >via paddle. There is also no receive and no transmit (I sofar completed
      >only 80m filter board) My kit came without the 2N7002 MOSFETS so I

      Every board which I have fixed for people so far have only required finding
      and fixing the soldering problems.

      72,
      Steve, KD1JV
      "Melt Solder"
      White Mountains of New Hampshire
      http://kd1jv.qrpradio.com




      --
      Sergej Kindsvater
      DF6MU, W6MHZ

      Normal people believe that if it ain't broke, don't fix it. Engineers believe that if it ain't broke, it doesn't have enough features yet.
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