I find that rather impossible to believe - 300m of thick cable being a dummy load at 137kHz ! Go back to the fundamental equations and calculate properly rather than rely on tables and software used
To All from PA0SE dummy rely snip snip Andy says "Go back to the fundamental equations and calculate properly". A good advice but Andy did not follow it himself. snip snip I could not spot a computat
<< Does any reader have a drum of coaxial cable and a low frequency bridge test set? A practical measurement should sort out a quantitative result. >> Not a test set for measuring at 136k. But abt 70
The inductance of a coax 'stub' is frequency dependent ! According to the formula for a loss-less cable (given in an earlier mail, should be OK for 136kHz) 70m of RG58 cable should be about 17uH. For
For an estimate of losses : Skin depth of copper at 137kHz is approximately 0.18mm From D = 503 SQRT(Resistivity / Freq / uo) For Cu Resistivity = 1.7E-8 Ohms / m, and uo (magnetic permeability) = 1
<< So Q = 1722/4.46 = 386, which is somewhat better than your conventional coil. >> If someone actually performs such a measurement (I hope someone can; math is wonderful and theory is indispensible,
