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Ver6.1 Rocky image rejection ... power saturation

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  • patbilldavis
    Hello guys ... I ve been too busy using the Ver6.1RxTx and other things to follow up on a discovery... I seem to have an issue with my Ver6.1RxTx that I was
    Message 1 of 1 , Apr 26 8:55 AM
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      Hello guys ... I've been too busy using the Ver6.1RxTx and other
      things to follow up on a discovery...

      I seem to have an "issue" with my Ver6.1RxTx that I was unaware of
      until yesterday.

      When doing alpha testing of the Rocky3.0 I was having problems with
      setting the image rejection. Alex indicated that I was the only one
      that he was aware of that was having that problem. I discovered then
      that if I reduced the I/Q drive in the TX setup in Rocky I could set
      the rejection without problems. I worked a few stations with Rocky,
      but continued to use M0KGK's software. I never really thought much
      more about it.

      Last weekend, Alex released Rocky 3.1 with PSK ... Oh my!! I thought
      it would be lots of fun to run PSK31 with Rocky since it was a mode
      option and no additional software was required. So I loaded 3.1 and
      went to work ... once again I could NOT get the image rejection to do
      much at all. (Hummm just like when I was testing 3.0). I have no RF
      power indicator on the Ver6.1 so I pulled out the scope and hung it on
      the RF output of the Ver6.1 and discovered the reason ... something in
      the TX side of the 6.1 is saturating ... I had 10db more I/Q input
      than what the the 6.1 would take. I reduced the I/Q level with the
      level control on the TX setup in Rocky3.1 by 10db, just below
      saturation and image rejection could again be set very well ... image
      into the noise, no problem.

      I have not tried to trouble shoot yet ... I need to get the scope
      out again and try to find what is saturating.

      I'm guessing that this is the reason my Ver6.1 will not run more
      than 500mw output (both on 80 and 40m)...

      So if you experience problems setting Rocky image rejection, be sure
      you are not saturating ... Why this is not a problem when setting
      image rejection with M0KGK's software, I don't know ... I would guess
      I can reduce the image with it even more if I reduce the I/Q input level.

      I'm having a "blast" running PSK31 with Rocky and the Ver6.1 now ...
      that's taking time away from my QRPp CW QSOs..

      73 and good Softrock DX to all, watch for me on 40m ... Bill K0AWU
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