This is my Guanella balun built from the Amidon FT-240K core. Wound
per instructions in their Transmission Line Transformers Handbook page 31.
Amidon sells a kit
with the core, wire, Teflon, and book.
Click on images below for a larger graph.
Balun terminated with a 200 Ohm resistor where the OCF connects
80 Meter OCF, 14 gage PVC covered stranded wire, 38% fed from one end, 30 foot high.
Now lets add some confusion?
Below is this same balun mounted on and using the antenna wire from our communications trailer. ( See this link ). Aside from the different wire insulation, house wire on the antenna range and the Wireman "silky" on the trailer, the big difference is: 1) The metal trailer. 2) Fiberglass mast, low center, 19' above ground. 3) Ends at 10' at the trailer and 20' at the test range. So, where the devil does the 160 Meter dip come from in an 80 Meter OCF?
Dark line is the graph on the trailer, 19' fiberglass mast.Light line is graph on the test range 30' metal mast.