Cushcraft 15-3CD 4 Feet Below a Hygain 204BA
Free Space
21.174 MHz
7 Wires, Inches
12      .000  -136.765      .000      .000   136.765      .000  1.000
12    81.001  -131.558      .000    81.001   131.558      .000  1.000
12   162.002  -126.753      .000   162.002   126.753      .000  1.000
12      .000  -208.029    48.000      .000   208.029    48.000  1.000
12   122.874  -196.445    48.000   122.874   196.445    48.000  1.000
12   211.624  -185.470    48.000   211.624   185.470    48.000  1.000
12   307.248  -179.307    48.000   307.248   179.307    48.000  1.000
1 Source
17 100 0
0 Loads

This illustrates how the performance of a 3 el 15m Yagi can be degraded by a
nearby 4 el 20m Yagi.  The presence of the 204BA reduces the 15m forward gain
about 3 dB and degrades the F/B dramatically.  Turning the 15m beam 90 deg
fixed the 15m problem, but then the boom of the 15m antenna interfered with the
204BA.  Try removing the 204BA elements from this file to see what the naked
15-3CD can do.