[Lf] Antenna loss resistance & impedance vs soil

[W3HXF at aol.com]

Has anyone seen any list of the relative losses in:
> sand
> sandy lome
> good soil
> rockey soil
> rock
> over mineral mines (in Idaho)
> water saturated ground (underground stream)
> water (fresh)
> water (salt)
>
Does their relative standing change with
large changes in frequency ( LF to HF to UHF)?
73, Bill W3HXF


> Re- antenna loss resistance: A basic difficulty with direct impedance measurement of an LF antenna is that the loss resistance is much smaller than the magnitude of the reactance.
> For example, an antenna with R(loss) = 50ohm, C = 500pF, has a capacitive reactance of 2.3405kohm. The magnitude of the combined impedance is 2.341kohm, and the phase angle 88.8degrees, so quite close to that of the pure capacitance. A bridge will produce an accurate measurement of the capacitance component, but much larger errors will occur in measuring the resistive component, which is only a few percent of the total
impedance. Even a very good bridge will struggle to get anything more than a rough figure for the resistance.
>
> A better way to measure loss resistance is to cancel out the capacitive reactance of the antenna with a series loading coil (ie. tune it to resonance), and then measure the remaining resistance, as done by PA0SE.
>
> A seperate measurement is then required to determine the loss resistance of the loading coil. This can be done by resonating the loading coil with a low-loss capacitor in place of the antenna, and measuring the resistance again.