I searched through the archives and found plenty of references to using ferrites/toroids as baluns, but nothing that led me to using ferrites/toroids as part of LC traps for dipoles. Have I missed th
ORIGINAL MESSAGE: -- REPLY FOLLOWS -- Baluns are not resonant circuits, but traps are. Baluns do not have the high circulating currents that traps do and that is one of the important differences. A t
Yet many of us are using autotuners (which all have powdered iron inductors) on pathological matching cases, probably with high circulating currents. There *is* a QRP-level trapped dipole (don't rem
I would say it's not so much that ferrites are notorious for saturating, it's more like it's easy to screw up a ferrite design so that it will saturate. People build multi tens of kW switching power
You can get reasonably good Q's with iron powder. They are often used in linear amplifier tank circuits for instance (most of the Alpha amps use an iron powder core for the low frequency portion of t
It does... I would imagine the domimant loss mechanism in any trap is IR losses in the coil, and the fact that a air core inductor is physically larger might mean that even if you have some losses in
ORIGINAL MESSAGE: -- REPLY FOLLOWS -- Yes, it can be done but doing it right requires some careful engineering. It's not something you want to slap together in a couple of minutes and put up in the a
There's an old DOS program called "Coil.exe" that calculates inductance and self-resonance (both parallel and series) for single layer cylindrical air-wound coils. I have no idea how accurate it is f
You got that right.... That *might* not be true... But, it's a pretty complicated analysis to find out whether it is. You'd have to look at core losses (which will be pretty low), which is fairly str
It is an intriguing idea for a top-loaded mobile antenna. One of the problems with pure top loading is to keep the field of the coil from encountering the top hat. A T-500-2 core would pretty much c