Following a rather intense debate between two friends of mine about how efficient an antenna tuner actually is, and sketchy info at best on loss characteristics of tuners in general, this weekend I plan on running some scans for return loss through my MFJ Deluxe Versa Tuner II (MFJ-949E) tuner into both high impedance (open circuit) and low impedance (short circuit) loads. The frequencies scanned will cover between 1 and 30 MHz as those are the design frequencies of the antenna tuner itself. I will run these scans on all inductor settings A through L, and for this test the capacitors will be set at half way. Is anyone willing to give any predictions on outcomes?
My current prediction is, except for possible self resonant points in the tuner, we will not see the return loss exceed 1 dB. I also think that should we see any self resonant points, those points will be largely narrow peaks of return loss that are orders of magnitude higher than other frequencies in the scans, possibly off of whatever scale I use (likely a 10 dB scale unless I need a different scale to measure accurate readings).
Also a note, as the signal passes through the tuner twice for return loss measurements, the actual losses of the tuner at given frequencies will actually be half the return loss value in decibels.
The DB
My current prediction is, except for possible self resonant points in the tuner, we will not see the return loss exceed 1 dB. I also think that should we see any self resonant points, those points will be largely narrow peaks of return loss that are orders of magnitude higher than other frequencies in the scans, possibly off of whatever scale I use (likely a 10 dB scale unless I need a different scale to measure accurate readings).
Also a note, as the signal passes through the tuner twice for return loss measurements, the actual losses of the tuner at given frequencies will actually be half the return loss value in decibels.
The DB