Contents
What is a high q coil?
The higher the frequency of the alternating current, the higher the inductive reactance. However, although the coil is a conductor, the wire winding has certain resistance components (R). In simple terms, a higher Q value means lower losses and better suitability for use as a high frequency inductor.
How does a coil antenna work?
Some antennas are made of loops of wire. These antennas detect the magnetic field rather than the electric field. Just as a magnetic field through a coil of wire is produced by the current in that coil, so too a current is induced in a coil of wire when a magnetic field goes through that coil.
What is the Q factor of a coil?
Quality factor (Q) or coil Q-factor is a dimensionless unit for the losses of a coil, quartz, or a resonator. For coils this refers to the ohmic losses of the coil-wire. They are inversely proportional for the coil quality and are calculated from the ratio of reactance to ohmic resistance.
What does a loading coil do?
A loading coil or load coil is an inductor that is inserted into an electronic circuit to increase its inductance. The term originated in the 19th century for inductors used to prevent signal distortion in long-distance telegraph transmission cables.
Why do I need a high qcoil loading coil?
I attempted to build a high Qcoil in order to minimize losses in the coil. The unfortunate fact is that loading coils for 160 meter vertical antennas will almost always have enough loss to dissipate a significant percentage of the total power delivered to the antenna.
How big is a high Q loading inductor?
For this reason many of the details and justifications for the advice given have been placed in appendix TBD. Much of the earlier discussion assumed relatively low QL values, 200-400, which represent small inductors (dimensions of a few inches).
Which is better an inductor or a loading coil?
This is why very large mobile antenna loading coils generally offer marginal improvement over smaller inductors.
What should the QL be for a LF antenna?
Descriptions of large LF antennas often mention tuning inductor (or “helix”) QL of several thousand[1]. Past experience with HF inductors might make such high numbers seem a fantasy but that’s not the case! QL approaching or even exceeding 1000 is practical for mH inductances at LF or MF without the use of exotic materials.