[QCWA] Baluns part 12

[Jeffrey D Angus]

Materials...

Not all ferrites are created equal.

For broad band operation, a lower permeability is
required. 250 works well (Type 61)

Larger permeability works, but is best suited for
low band operation. (type 43 for example, works
well from 160-40 meters.)

Core size is important. The larger cores, such as
FT-240 (2.4" OD) will support up to a KW or two.
Smaller cores like FT-120 (1.25" OD) should be
limited to 100 watts or so.

Surprisingly enough, #16 AWG lamp (or Zip) cord
is fairly close to 150 ohms Zo, so it is a very easy
choice for making 9:1 baluns with. A lot easier to
deal with that winding with #16 AWG magnet wire
and having to maintain the correct spacing every
turn.

Hoever, even twisted together, two enamled wires
are close to 80 Ohms Zo, so your best bet for 1:1
baluns is using RG-58 on a toroid or slipping a LOT
of ferrite beads around RG-8.

Jeff-1.0
wa6fwi