创建页面,内容为“{| class="wikitable" |+工作频率在30MHz以下时的接收机S表示值 !S表示值 !相对强度 !收信电压 !收信功率(50Ω) |- !S1 | -48dB |0.2μV | -141dBm |- !S2 | -42dB |0.4μV | -135dBm |- !S3 | -36dB |0.79μV | -129dBm |- !S4 | -30dB |1.6μV | -123dBm |- !S5 | -24dB |3.2μV | -117dBm |- !S6 | -18dB |6.3μV | -111dBm |- !S7 | -12dB |13μV | -105dBm |- !S8 | -6dB |25μV | -99dBm |- !S9 |0dB |50μV | -93dBm |- !S9+10 |10dB |160μV | -83dBm |- !…” |
无编辑摘要 |
||
| (未显示同一用户的2个中间版本) | |||
| 第1行: | 第1行: | ||
在绝大多数的无线电收信设备上都安装有S表,用来测量接收信号的强度,而S表的示值,在业余无线电通信中,RST信号报告中的“S”,即信号强度,可直接根据S表的示值给出。 | |||
S表中,从S1至S9,示值每增加1点,代表接收信号强度增加6dB,接收信号电压增大一倍(x2)。 | |||
同理,S表的示值每减少一点,代表接收信号的强度减小6dB,接收信号电压为之前的一半(x0.5)。 | |||
S表示值中的S9已经是非常强的信号了,对于强于S9的信号,改用10dB递增的方式来表示。例如S表中指示“S9+30”,代表接收信号强度比S9大30dB。 | |||
在现代的接收机系统中,存在两种S表示值的参考系统,以30MHz工作频率作为界限,如下两表所示。 | |||
在30MHz以下的工作频率,通常对应于短波电台的S表,S9被定义为“50欧姆天线口阻抗下,接收信号电压为50μV”。 | |||
在30MHz以上的工作频率,通常对应于UV段电台的S表,S9被定义为“50欧姆天线口阻抗下,接收信号电压为5μV”。 | |||
在一些比较古老的接收机中,S表示值的定义与现代接收机不同。S9被定义为“50欧姆天线口阻抗下,接收信号电压为100μV”,在此略过不做详细介绍。 | |||
{| class="wikitable" | {| class="wikitable" | ||
|+工作频率在30MHz以下时的接收机S表示值 | |+工作频率在30MHz以下时的接收机S表示值 | ||
| 第9行: | 第24行: | ||
| -48dB | | -48dB | ||
|0.2μV | |0.2μV | ||
| - | | -121dBm | ||
|- | |- | ||
!S2 | !S2 | ||
| -42dB | | -42dB | ||
|0.4μV | |0.4μV | ||
| - | | -115dBm | ||
|- | |- | ||
!S3 | !S3 | ||
| -36dB | | -36dB | ||
|0.79μV | |0.79μV | ||
| - | | -109dBm | ||
|- | |- | ||
!S4 | !S4 | ||
| -30dB | | -30dB | ||
|1.6μV | |1.6μV | ||
| - | | -103dBm | ||
|- | |- | ||
!S5 | !S5 | ||
| -24dB | | -24dB | ||
|3.2μV | |3.2μV | ||
| - | | -97dBm | ||
|- | |- | ||
!S6 | !S6 | ||
| -18dB | | -18dB | ||
|6.3μV | |6.3μV | ||
| - | | -91dBm | ||
|- | |- | ||
!S7 | !S7 | ||
| -12dB | | -12dB | ||
|13μV | |13μV | ||
| - | | -85dBm | ||
|- | |- | ||
!S8 | !S8 | ||
| -6dB | | -6dB | ||
|25μV | |25μV | ||
| - | | -79dBm | ||
|- | |- | ||
!S9 | !S9 | ||
|0dB | |0dB | ||
|50μV | |50μV | ||
| - | | -73dBm | ||
|- | |- | ||
!S9+10 | !S9+10 | ||
|10dB | |10dB | ||
|160μV | |160μV | ||
| - | | -63dBm | ||
|- | |- | ||
!S9+20 | !S9+20 | ||
|20dB | |20dB | ||
|500μV | |500μV | ||
| - | | -53dBm | ||
|- | |- | ||
!S9+30 | !S9+30 | ||
|30dB | |30dB | ||
|1.6mV | |1.6mV | ||
| - | | -43dBm | ||
|- | |- | ||
!S9+40 | !S9+40 | ||
|40dB | |40dB | ||
|5mV | |5mV | ||
| - | | -33dBm | ||
|- | |- | ||
!S9+50 | !S9+50 | ||
|50dB | |50dB | ||
|16mV | |16mV | ||
| - | | -23dBm | ||
|- | |- | ||
!S9+60 | !S9+60 | ||
|60dB | |60dB | ||
|50mV | |50mV | ||
| - | | -13dBm | ||
|} | |} | ||
{| class="wikitable" | {| class="wikitable" | ||
| 第89行: | 第104行: | ||
|- | |- | ||
!S1 | !S1 | ||
| | | -48dB | ||
| | |20nV | ||
| | | -141dBm | ||
|- | |- | ||
!S2 | !S2 | ||
| | | -42dB | ||
| | |40nV | ||
| | | -135dBm | ||
|- | |- | ||
!S3 | !S3 | ||
| | | -36dB | ||
| | |79nV | ||
| | | -129dBm | ||
|- | |- | ||
!S4 | !S4 | ||
| | | -30dB | ||
| | |160nV | ||
| | | -123dBm | ||
|- | |- | ||
!S5 | !S5 | ||
| | | -24dB | ||
| | |320nV | ||
| | | -117dBm | ||
|- | |- | ||
!S6 | !S6 | ||
| | | -18dB | ||
| | |630nV | ||
| | | -111dBm | ||
|- | |- | ||
!S7 | !S7 | ||
| | | -12dB | ||
| | |1.3μV | ||
| | | -105dBm | ||
|- | |- | ||
!S8 | !S8 | ||
| | | -6dB | ||
| | |2.5μV | ||
| | | -99dBm | ||
|- | |- | ||
!S9 | !S9 | ||
| 第134行: | 第149行: | ||
|- | |- | ||
!S9+10 | !S9+10 | ||
| | |10dB | ||
| | |16μV | ||
| | | -83dBm | ||
|- | |- | ||
!S9+20 | !S9+20 | ||
| | |20dB | ||
| | |50μV | ||
| | | -73dBm | ||
|- | |- | ||
!S9+30 | !S9+30 | ||
| | |30dB | ||
| | |160μV | ||
| | | -63dBm | ||
|- | |- | ||
!S9+40 | !S9+40 | ||
| | |40dB | ||
| | |500μV | ||
| | | -53dBm | ||
|- | |- | ||
!S9+50 | !S9+50 | ||
| | |50dB | ||
| | |1.6mV | ||
| | | -43dBm | ||
|- | |- | ||
!S9+60 | !S9+60 | ||
| | |60dB | ||
| | |5.0mV | ||
| | | -33dBm | ||
|} | |} | ||
[[分类:技术普及]] | |||