灵敏度uv与dBu对照数.doc

灵敏度uv与dBu对照数电压uvdBu近数值备注0.1-20-200.13-17.7-180.2-13.97-140.25-12.04-120.3-10.46-100.38-8.4-80.5-6.02-60.7-3.1-3100计算方法：例：Xuv则列式：20logxuv=YdBu按计算器的X各数再按log读出的数再乘以20即为灵敏度dBu。音频输出功率与dBm对照表功率（mw）负裁（8）电压（v）电压表（600）指示值（dBm）功率（mw）负裁（8）电压（v）电压表（600）指示值（dBm）250.447-4.787502.4499.995500.633-1.768002.5310.28750.77508502.60810.541000.8941.29002.68310.791251.002.219502.75711.021501.0953.0010002.82811.242001.2654.2615003.464132501.4145.222000414.263001.5496.0225004.47215.223501.6736.6930004.89916.014001.7897.2735005.2916.694501.8977.7840005.65717.2750028.234500617.785502.0988.6550006.32518.236002.199.02755006.63318.656502.289.3760006.92819.037002.3669.69665007.21119.3770007.48319.7音频输出功率与电压的换算法一、 电压表的零刻度阻抗为600；二、 接收机的负载阻抗（嗽叭）8；三、 1mv的功率在600负载的电压：V0= OZ = 110-3600 = 0.775v负载功率在8喇叭上的电压：V = Z再由20lgV=20lgV= dBm值V00.775例：接收机输出功率（8），=0.5W则V= 0.58 = 2V所以dBm的读数为：20lgV=20lg2= 8.23dBmV00.775分贝换算表功率比电压和电流比分贝（+）（）电压和电流比功率比1.0001.0000.01.0001.0001.0231.0120.10.98860.97721.0471.0230.20.97720.95501.0721.0350.30.96610.93331.0961.0470.40.95500.91201.1221.0590.50.94410.89131.1481.0720.60.93330.87101.1751.0840.70.92260.85111.2021.0960.80.91200.83181.2301.1090.90.90160.81281.2591.1221.00.89130.79431.5851.2592.00.79430.63101.9951.4133.00.70790.50122.5121.5854.00.63100.39813.1621.7785.00.56230.31623.9811.9956.00.50120.25125.0122.2397.00.44670.19956.3102.5128.00.39810.15857.9432.8189.00.35480.125910.003.16210.00.31620.1000012.593.54811.00.28180.0794315.853.98112.00.25150.0631019.954.46713.00.22930.0501225.125.01214.00.19950.0398131.625.63215.00.17780.0316239.816.31016.00.15850.0251250.127.07917.00.14130.0199563.127.94318.00.12590.0158579.438.91319.00.11220.01259100.0010.00020.00.10000.0100010331.6230.00.031620.0010010410240.010-210-4105316.2350.03.16210-310-510610360.010-310-610