Antenna db Gain Chart

DB GAIN CHART

Antenna Gain
Watts Multiplier
ERP with 100 Watts Input
1
1.2
120
2
1.6
160
3
2.1
210
4
2.5
250
5
3.2
320
6
4
400
7
5.1
510
8
6.3
630
9
8
800
10
10.2
1020
11
12.6
1260
12
15.9
1590
13
20
2000
14
25.1
2510
15
31.6
3160
16
39.9
3990
17
50.2
5020
18
63.3
6330
19
79.5
7950
20
100
10000

Remember that when calculating the ERP of your station you must take into account all antenna system gains and losses, including feedlines, connectors, adapters, etc.

Example: if you have an antenna with a 7 db gain, coax with the calculated loss (based on type, length, and operating frequency) of 2 db, and total connector losses of 1 db, you have 7-2-1 = 4 db of gain. Thus, if your rig is transmitting 100 Watts peak, you will have a peak ERP of 100 x 2.5 (multiplier) = 250 Watts.

Need to calculate your coaxial cable losses based on coax type, length, and operating frequency? Here is the link to a very handy coaxial cable loss calculator. Clicking on it should open the calculator in a new browser tab/window, which you can simply close when you’re done and this page should still be visible.