SWR

[starszy]

Czy to jest coś warte?

http://www.ebay.com/itm/RF-Detector-SWR ... Sw5dNWkAj4

Skopiowane ze strony producenta

The principle is to connect the RF Detector to the coupler's Vreflected port and measure the voltage using a multimeter, then measure the Vforward port, and calculating the SWR to get a ballpark figure of how efficient your antenna is performing (input power).

Example: to calculate the VSWR, let's assume the Vref is 0.25V and Vfwd is 1.35V - the complete formula would then be VSWR = (1+(0.25V/1.35V))/(1-(0.25V/1.35V)) = 1.45, which is 1.45:1 or about a 97% efficient antenna - very good in other words.

Percentage losses:

SWR Reading Power loss Output to antenna
1.0:1 0.0% 100.0%
1.1:1 0.3% 99.7%
1.2:1 0.8% 99.2%
1.3:1 1.7% 98.3%
1.4:1 2.7% 97.3%
1.5:1 3.0% 97.0%
1.6:1 5.0% 95.0%
1.7:1 6.0% 94.0%
1.8:1 8.0% 92.0%
2.0:1 11.0% 89.0%
2.2:1 14.0% 86.0%
2.4:1 17.0% 83.0%
2.6:1 20.0% 80.0%
3.0:1 25.0% 75.0%
4.0:1 38.0% 62.0%
5.0:1 48.0% 52.0%
6.0:1 55.0% 45.0%
10.0:1 70.0% 30.0%

[Ben]

To jest sam detektor, do tego potrzebny jest jeszcze sprzęgasz kierunkowy (directional coupler), tu masz cały wątek.

Troszkę drogo, same elementy to koszt rzędu ~ 15-20zł.