Re: Loading inductor Question

Posted by Ignacy on May 01, 2012; 3:15pm
URL: http://elecraft.85.s1.nabble.com/Loading-inductor-Question-tp7513850p7517125.html

MFJ-902 tuner uses a single toroid with taps. The toroid becomes hot on some frequencies with 100W but survives. I guess losses are small compared to convenience of a very small unit.

From what I understand, the iron cores can have Q in excess of 300 if they are below saturation. How much will they can handle depends on the load. A reactance of 300 will add a resistance loss of 1 Ohm, and a reactance of 3000 will add 100 Ohm.  So the same toroid can handle KW with a longer vertical but could overheat at 100W with a short vertical.

Ignacy

Fred Townsend wrote

Ken:
.... Don't use toroids if you need taps.
73
Fred, AE6QL