SWR BRIDGE

The SWR meter or VSWR (voltage standing wave ratio) meter measures the standing wave ratio in a transmission line. This is an item of radio equipment used to check the quality of the match between the antenna and the transmission line.

The VSWR meter should be connected in the line as close as possible to the antenna. This is because all practical transmission lines have a certain amount of loss, causing the reflected power to be attenuated as it travels back along the cable, and producing an artificially low VSWR reading on the meter. If the meter is installed close to the antenna, then this problem is minimized.

this a SWR bridge that i make it will cover from 1MHZ -150MHZ  It use a torride transformer to couple the load current to detector ciruit the coupling is 20:1 ratio

Componts list

R1       1k 0.25w                               C1    7pF  Mica                   C7     4.7 nF Ceramic

R2      1k 0.25w                                C2   7pF Mica                     C8     10uF Tantuium 15

R3       10K 0.25w                             C3   4-65 pF Trimmer ceramic

R4       10k 0.25w                              C4    4-65 pF Trimmer ceramic

R5    100   ohms 0.25w                     C5   4.7 nF Ceramic

R6    100     ohms 0.25w                    C6   10uF Tantuium 15 v

R7    100     ohms 0.25w 

R8    100     ohms 0.25w 

D1   0A91,0A81 Germanium or BAT46 Schottky diodes

D2  0A91,0A81 Germanium or BAT46 Schottky  diodes

Please Note D1 and D2 Must be matched also R5 and R6  and R7 and R8 To determine the sensitivity and linearality  ( R5 =39 ,R6=37  and R7 =35 and R8 =35 )