Fw: Re: Fw: Re: Fw: Re: [Antennas] More Ladder Lines and Beams
Sandy and Kees Talen
[email protected]
2002年1月27日 14:21:37 -0600
> If you want a 'balance' to ground, then it requires 'splitting' the AB
>winding into two windings, each with 1/2 the turns as below:
>c---- A
>c winding #1 [1/2 the turns]
>c---- B
>c---- C
>c
>c winding #2
>c
>c---- D
>c---- E
>c
>c winding #3
.c
>c---- F
>c---- G
>c winding #4 [1/2 the turns]
>c---- H
>again: connect B to C, D to E, F to G, attach 450 ohm balanced load to
>A and H, coax to either B/C or F/G with shield/ground to D/E ... voila!
>9:1 ... balanced .. grounded midpoint of windings!
........For RF applications you want tightly coupled windings (and the
resultant minimum reliance on lossy cores). For this reason every
toroid balun I've ever seen (or I have wound) has been using parallel
windings....in other words, bifilar, trifilar, etc.
I don't know how to factor in "1/2 the turns". Still took me 3 toroid
cores
to come up with a 9:1.
73s Kees K5BCQ