I constructed an 160m T similar to yours this year. Mine is 65' vertical
and 48' horizontal and also has a loading coil at the T junction. I
downloaded a demo version of W7EL and discovered that the antenna has a low
input resistance and very high capacitive reactance. By using a loading
coil the capacitive reactance will decrease but the input resistance will
remain the same. I designed my coil, using 12 gauge insulated wire, on a
PVC form to be approximately XL=250 ohms. I feed the antenna with a 50 ohm
to 25 ohm UNUN and a tapped MFJ coil to fine tune the SWR. The main take
away is that you should use as high Q coils as you can and you will also
need some sort of matching network.
73, Ryan K3XC
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