[Elecraft] 9:1 Balun AND "random antennas"

[Joe Subich, W4TV]

On 1/31/2017 1:50 PM, Jim Brown wrote:
> Last I looked, there was no description of the Elecraft "balun" telling
> us what it is. Perhaps Eric or Wayne could add that to the catalog
> listing for it.

The manual for the Elecraft BL2 shows exactly what it is:
     http://www.elecraft.com/manual/BL2_Balun_Rev_B.pdf

Takes exactly 30 seconds to look at the schematic to see that the BL2
is a Rutheroff balun - two common mode chokes with the input in
parallel and the output switchable between parallel (1:1) and series
(4:1).  Each pair of windings is roughly 100 Ohm line so the impedance
through the balun is a fairly good approximation of the desired value
in a 50 Ohm system.

73,

    ... Joe, W4TV