Are there some vendors of readily available (stock) inductors that have
reasonably good Q's (100) throughout the HF band?
I'm familiar with something like the Coilcraft "maxi springs"
(
http://coilcraft.com/maxi.cfm), and while they hit Q's of 100 by 30MHz, I'd
really like something that's already there by 3MHz or less (...and still have
a self-resonant frequency of 30MHz). This seems quite doable simply by
making a larger coil with thicker wire, I'd just like to find a place that
offers such inductors off-the-shelf rather than having to wind my own.
Inductance in the ballpark of 1-10uH would be good, although it's not
critical.
The goal here is to try out making some adjustable notch filters for a
receiver (by switching L's and C's in and out, like antenna tuners do).
Hence, high Q is important, but power handling capability isn't so much, and
anything smaller than a breadbox is fine size-wise.
Thanks,
---Joel