Product Details:
Teltonic RHO-tector wheatstone bridge. 2 1/2" SQ, 1 5/8"H-overall with connectors. The Rho-Tector which I know is a Wheatstone bridge. It has a built-indetector. The output is DC. You don't need a spectrum analyzer. You canuse a multimeter. I used it with a sweep generator which had a maximumoutput of about 56dBmV (about 8dBm).The easiest way of using it is to insert a switched attenuator betweenthe generator and the RF input port. Connect the 1:1 load to Z1 or Z2(the 'reference' port), and a 2:1 to the other (the 'unknown' port).This represents an RLR of 10dB.Set as much attenuation in which is consistent with getting a sensiblelevel of DC out (say, 20dB). Note the reading.Remove the 2:1 load, and connect the antenna. Re-set the attenuator togive the same DC reading. Note the attenuator setting.The RLR of the antenna is simply 10dB + or - the difference in theattenuator readings.There is a small amount of error because the loading on the generator isaffected by the load on the 'unknown' port (unless the generator haszero output impedance, which it won't have). There ways of reducingthis, but it isn't worth it. Your answer will be good enough for mostpurposes.