These are the manufacturer's provided gain tables to show gain or loss for various popular circular polarized antenna models used by LPFM and FM translator stations.
Nicom BKG-77 & BKG-88
Bays |
Full Wave |
0.85-spaced |
0.5-spaced |
1 |
-3.28 |
-3.28 |
-3.28 |
2 |
-0.05 |
-0.45 |
-1.55 |
3 |
1.88 |
1.49 |
0.00 |
4 |
3.22 |
2.99 |
1.14 |
6 |
5.12 |
4.64 |
2.8 |
8 |
6.53 |
6.0 |
3.98 |
Nicom BKG1P
Bays |
Full Wave |
0.85-spaced |
0.5-spaced |
1 |
0 |
0 |
0 |
2 |
2.99 |
2.53 |
1.49 |
3 |
4.91 |
4.49 |
3.05 |
4 |
6.28 |
6.00 |
4.18 |
6 |
7.99 |
7.5 |
5.8 |
8 |
8.6 |
8.38 |
7.08 |
Shively 6812b / c
Bays |
Full Wave |
0.5-spaced |
1 |
-3.39 |
-3.39 |
2 |
0.03 |
-1.51 |
3 |
1.92 |
0.08 |
4 |
3.21 |
1.19 |
5 |
4.20 |
2.10 |
6 |
4.99 |
2.84 |
8 |
6.26 |
4.04 |
SWR FMEC Plus
Bays |
Full Wave |
0.75-spaced |
0.5-spaced |
1 |
-3.556 |
-3.556 |
-3.556 |
2 |
-0.182 |
-0.292 |
-1.580 |
3 |
1.746 |
1.449 |
0.052 |
4 |
3.105 |
2.660 |
1.183 |
5 |
4.133 |
3.619 |
2.103 |
6 |
4.997 |
4.403 |
2.842 |
8 |
6.346 |
5.640 |
4.026 |
10 |
7.389 |
6.818 |
4.954 |
ERI 100A
Bays |
Full Wave |
0.5-spaced |
1 |
-3.768 |
-3.768 |
2 |
-0.458 |
-2.007 |
4 |
2.833 |
0.704 |