Actually, it sounds like the normal SWR fluctuation with a mobile antenna. A difference of 0.2 or 0.4 with SWR just doesn't amount to anything. As for the difference in readings between the built-in and external meter, don't pay any attention to one of them. Which one should you ignore? Since built-in meters tend not to be all that accurate, and can certainly be not very 'specific', that's the one I'd ignore.
Power has nothing to do with SWR. It can have a lot to do with the accuracy of any particular SWR meter's readings, which is also normal and why meters can be, or are required to be, re-calibrated with power changes.
I would be one of the first to suggest not using 'Rat Snack' coax but as long as the same jumper is used for all of the testing it remains a 'constant'. I would always 'change' any readings by the same amount. I really doubt if that's a problem.
And the biggy, if you ever see an ideal '1:1' SWR reading and it doesn't ever change, then you'd better patent that set up, it's a miracle. That ideal SWR reading is only possible when everything is perfect, and that's never going to happen (except in very miraculous circumstances).
- 'Doc
Power has nothing to do with SWR. It can have a lot to do with the accuracy of any particular SWR meter's readings, which is also normal and why meters can be, or are required to be, re-calibrated with power changes.
I would be one of the first to suggest not using 'Rat Snack' coax but as long as the same jumper is used for all of the testing it remains a 'constant'. I would always 'change' any readings by the same amount. I really doubt if that's a problem.
And the biggy, if you ever see an ideal '1:1' SWR reading and it doesn't ever change, then you'd better patent that set up, it's a miracle. That ideal SWR reading is only possible when everything is perfect, and that's never going to happen (except in very miraculous circumstances).
- 'Doc