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High initial SWR


 

I recently complete a ATU-100 kit, built and re-flashed with the QRP mod.

When I run in Auto mode, the tuner re-tunes every time I start to transmit.? This appears to be because when I begin to transmit, there is a SWR spike, so the tuner thinks it needs to tune, but in reality the high SWR is transient and the settings already tuned are just fine.? I can see this happening on the display - testing in manual mode.? I see the initial SWR be high, then immediately come down where it should be.

Is there a way to prevent this SWR spike from happening? or alternatively, have auto mode pause a bit until the SWR reading settles.

Just as a side note in case it matters, when I transmit without tuning (high SWR) the power reading is high.? For example, my uBitx puts out about 15 watts on 80 meters, but before tuning I have seen a reading has high as 42 watts on the display.? This comes down to the expected value once tuned. I have noticed similar behavior on other devices, just not to this degree.

Thanks
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Dennis

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