My copy is a little smaller with a 70cm loop made from 19mm.PVC. It has 650 turns 1.5mm PVC isolated electrical wire .Coil value is 134.6 uH. There is no need for a tuning capacitor and the feedpoint has a low Z . Power handling is easy 100 Watts and the recieved signals have a verry low noise levell. This antenna radiates like a dipole , that makes it perfect for window use. I could make clean and loud contacts throughout Europe on my first attempt having bad conditions. At the feedpoint is a line choke made of a ferrite rod with 15 turns RG-58 , giving about 1000 Ohms at 20m. SWR is 1.7 at 14.200MHz with a sharp second resonance at 26.140 MHz and a third on 37.485MHz .This little Russian is a big performer an will stay at my apartment window for sure HI, however the bigger origional design will even be more efficient. All contacts were made with 10 Watts PEP SSB .Do you live in a condo/apartment without a balconey ? Give it a try. I can work almost any station that i hear (-: I even think that clever winding could create a dual band antenna for 20 -10m.because of the multiple resonances.The easyest way to build this antenna is to wind the coil on the tube before bending to a loop, this prevents the tube from collapsing for the coil acts as a mold.
|The effective line choke|
|First results under bad conditions|