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70101Re: [softrock40] Re: What's the most TX power anyone has amplified an RXTX to? Just out of curiosity...

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  • Parks, Tony
    Nov 16, 2012
      Good Afternoon All,

      I have done the following several time to null the TX image when using Rocky 3.7 and think it works right but I would be interested in feedback, positive or negative.

      Rocky 3.7 continues the RX function when in TX with the RXTX Ensemble transceiver.  The RX antenna connection is open to the antenna path via Q10 biased off.  Moreover, the RX antenna connection over to the QSD circuit is shorted to ground by Q11 and the QSD circuit is disabled by the /OE lines of U10 being allowed to be pulled to 5 volts with Q9 off.

      What I have done is to clip a lead from the top lead of R63 to circuit ground to enable the QSD circuit and get an  Rocky RX spectrum display.  This allows the use of the Rocky TX balance adjustment to "null" the TX image.  It probably is necessary also to reduce the TX level output to keep the RX function from saturating even with the antenna input grounded.

      Any thoughts?

      Thanks and 73,
      Tony KB9YIG

      On Fri, Nov 16, 2012 at 1:28 PM, kk4dcf <oohay@...> wrote:

      > Maybe, but only if you admit it:) WSPR chat scrolls off the bottom, as far as I know it gets lost. So I thought I could mention that
      > without accusing anybody in particular.
      > Don't stop trying, learn what to do. WSPR is good for QRP. Given good conditions 1 watt will reach everywhere on 40m and above. And
      > much less may be used successfully.

      I'm certain it was me. The issue was that I built the kit with TX jumpers crossed and RX jumpers straight for PSDR and then started using linux instead. I forgot I had done that.

      That mistake points out to me that I do not have the equipment needed to do this. Especially the most basic testing gear, another receiver.

      The other major issue is that I don't have a viable home antenna. I've tried a handful of configurations and while I seem to be able to transmit decently (per WSPR and the 1 QSO I've had in the past week) the receive performance is terrible (also per WSPR and the 1 QSO). I expect to setup portable in a good open space next week to try and confirm my issues are antenna related. If that truly is the case then I'm probably just going to sell this all off and try again with a commercial rig in a few years when I move.


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