A rooftop run has 10 dB of cable loss between a radio and the antenna. About how much of the conducted power arrives at the antenna?
Select an answer to reveal the explanation.
Short Explanation
Ten decibels is a tenfold cut, and that loss is sitting in the cable before the antenna. About a tenth of your conducted power arrives. It is not a halving, and the cable did not retune the channel.
Full Explanation
A loss of 10 dB is about a factor of ten. Cable loss of 10 dB between the radio and the antenna leaves about one tenth of the conducted power at the antenna. One half would be about 3 dB, not 10. One quarter would be about 6 dB, not 10. Cable loss does not change the channel. It spends power as heat in the run. Ten decibels of cable loss leaves about one tenth of the power at the antenna. Not one half. Check one live client after the change and leave the rest of the floor alone until that client matches the result you expected. Read the live counters after you retest. Confirm the symptom is gone on the next attempt before you change a second setting anywhere else on that floor. Confirm the symptom is gone on the next attempt before you change a second setting anywhere else on that floor. Exam caveat: antenna gain after the cable can concentrate what remains. It does not restore the power the cable removed. Compute EIRP from what actually arrives at the antenna, plus gain. Operational check: measure at the radio and at the antenna end of the cable and expect the far end to read about 10 dB lower.