QMX T507 woes
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When I first built my QMX, it had zero RF output and the RX could only barely hear the strongest signals. Mike/w1mt suggested I remove T507, bypassing it across its C-C connection and see what?happened. That completely fixed my problem. And since SWR checking had not been implemented yet (that's what T507 is for), I then operated the QMX successfully on CW and FT8 for several weeks without T507. When Hans posted that he had gotten SWR functionality working on his development platform a few days ago, I decided to revisit T507. To make a long story short, I was back to no RF output and essentially no receive. I sent some pix of my board to Mike/w1mt and he immediately spotted my problem. I had done the single turn windings wrong (see attached photo). The instructions say to pass these single turn windings through "each" hole once. You can see how I interpreted that in the photo. I built T507 three times like this, never considering that that was wrong. What Mike pointed out was that these windings are straight pieces of wire going through a single hole each. Making that change got my QMX going 100%! Of course I studied the photos in the assembly manual carefully, but I somehow subconsiously convinced myself that my interpretation was consistent with them, without ever questioning it. I thought the loops in my implementation were either not visible, or omitted for clarity - how ironic! Apologies for this long post. I am slightly red-faced about my mistake and the hours spent not seeing it, but it might help someone else If the manually were updated to point out this possible misinterpretation. Loving my QMX now! 73, Randy, KS4L? |
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From experience, I can say that it has done no damage. I'm running from an 11.5v supply, if that matters. Also TX testing was done with a dummy load. 73, Randy, KS4L On Mon, Sep 25, 2023 at 10:12?AM Josh via <dcameraman=[email protected]> wrote: If someone were to transmit with T507 wired in the ¡°U¡± configuration . . . would that fry the receiver? As in ruined beyond repair? |
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One other thing, I tested transmit by sending a series of dits in CW - maybe 5-10 at a time. On Mon, Sep 25, 2023 at 10:16?AM Randy via <wrmoore47=[email protected]> wrote:
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Randy