Bob wrote:
David wrote:


Was just wandering if anyone has used or experimented with television
IF, Video and Detector coils, most are slug tuned coils that have a
few uh to several hundred uh, some are sheilded some are not, i have
about 500 that i bought years ago, a lot of them look very close too
the old loopstick type coils, looking for
ideas.


Unfortunately, the *Q* of those coils will be much too low for effective use
in crystal receivers. The best results I've had with "no power" receivers
involved the use of FET detectors and /very/ High-Q coils. The inductors
usually have to be large diameter air-cored, but you can get away with toroid
or ferrite rod types if you can accept poorer results. It's quite
illuminating to browse the offerings on the web.

Bob
How about making an Air Core Toroid. That can be made using a wax core.
Then after winding it,
some QDope or something in strips to hold the windings and then melting
the wax. Or maybe a foam
plastic core.

Bill K7NOM