饋(kui)(kui)(kui)(kui)線(xian)(xian)(xian)(xian)(xian)是連(lian)接(jie)在(zai)(zai)電臺(tai)和(he)天線(xian)(xian)(xian)(xian)(xian)之間的同軸電纜。在(zai)(zai)選(xuan)擇時(shi)應注(zhu)意如下的指標：阻抗(kang)：50Ω(市面上一般有75Ω和(he)50Ω兩種，請(qing)注(zhu)意區別)衰減：每(mei)米饋(kui)(kui)(kui)(kui)線(xian)(xian)(xian)(xian)(xian)對信號衰減分貝(u88)數，哀(ai)減越小(xiao)越好。線(xian)(xian)(xian)(xian)(xian)徑：饋(kui)(kui)(kui)(kui)線(xian)(xian)(xian)(xian)(xian)的直徑越粗和(he)屏蔽層越厚實的饋(kui)(kui)(kui)(kui)線(xian)(xian)(xian)(xian)(xian)衰耗(hao)越小(xiao)。饋(kui)(kui)(kui)(kui)線(xian)(xian)(xian)(xian)(xian)連(lian)接(jie)頭(tou)：饋(kui)(kui)(kui)(kui)線(xian)(xian)(xian)(xian)(xian)的兩頭(tou)必須(xu)和(he)天線(xian)(xian)(xian)(xian)(xian)和(he)電臺(tai)的接(jie)頭(tou)匹配(pei)，連(lian)接(jie)頭(tou)的阻抗(kang)也為50Ω，而且必須(xu)牢(lao)(lao)靠連(lian)接(jie)。饋(kui)(kui)(kui)(kui)線(xian)(xian)(xian)(xian)(xian)在(zai)(zai)留(liu)有余地的情況下盡(jin)可能(neng)短。安裝饋(kui)(kui)(kui)(kui)線(xian)(xian)(xian)(xian)(xian)時(shi)避(bi)免折彎，饋(kui)(kui)(kui)(kui)線(xian)(xian)(xian)(xian)(xian)廠家哪家好，饋(kui)(kui)(kui)(kui)線(xian)(xian)(xian)(xian)(xian)應固定好，不(bu)能(neng)隨風飄蕩，天饋(kui)(kui)(kui)(kui)接(jie)頭(tou)要擰緊(jin)并(bing)用(yong)放水膠(jiao)布(bu)纏牢(lao)(lao)，方向由下往上以防雨水滲(shen)入。在(zai)(zai)有條件的地方，能(neng)把(ba)饋(kui)(kui)(kui)(kui)線(xian)(xian)(xian)(xian)(xian)的外銅皮與大地相連(lian)接(jie)。

電(dian)(dian)(dian)(dian)(dian)源端(duan)向負載(zai)供電(dian)(dian)(dian)(dian)(dian)的電(dian)(dian)(dian)(dian)(dian)饋(kui)電(dian)(dian)(dian)(dian)(dian)線(xian)(xian)路(lu)。還有一種是(shi)進線(xian)(xian)回路(lu)，它有出線(xian)(xian)是(shi)到各個分柜(ju)的。 比如，饋(kui)線(xian)(xian)廠(chang)家(jia)供應，高壓有二(er)路(lu)進線(xian)(xian)， 有四(si)臺(tai)變(bian)壓器出線(xian)(xian)，饋(kui)線(xian)(xian)廠(chang)家(jia)銷售(shou)， 那從(cong)供電(dian)(dian)(dian)(dian)(dian)局過來的二(er)根總線(xian)(xian)接的柜(ju)就(jiu)叫(jiao)(jiao)進線(xian)(xian)， 變(bian)壓器出線(xian)(xian)的柜(ju)就(jiu)叫(jiao)(jiao)饋(kui)線(xian)(xian)，還有計量柜(ju)，PT柜(ju)等。饋(kui)電(dian)(dian)(dian)(dian)(dian)線(xian)(xian)中的“饋(kui)”字就(jiu)是(shi)“送”的意思，因此，新疆(jiang)饋(kui)線(xian)(xian)廠(chang)家(jia)，“饋(kui)電(dian)(dian)(dian)(dian)(dian)線(xian)(xian)”可以(yi)理(li)解(jie)為“送電(dian)(dian)(dian)(dian)(dian)的線(xian)(xian)”或“供電(dian)(dian)(dian)(dian)(dian)線(xian)(xian)”。其主要(yao)用途有兩個：一、傳輸提供電(dian)(dian)(dian)(dian)(dian)能；二(er)、傳送電(dian)(dian)(dian)(dian)(dian)信號。

同軸(zhou)電纜(Coaxial Cable)是指有兩個同心(xin)導(dao)體，而導(dao)體和屏蔽層(ceng)(ceng)又共用同一軸(zhou)心(xin)的(de)電纜。常見的(de)同軸(zhou)電纜由(you)(you)絕緣材(cai)料隔(ge)離的(de)銅線導(dao)體組成，在里層(ceng)(ceng)絕緣材(cai)料的(de)外部(bu)是另一層(ceng)(ceng)環形(xing)導(dao)體及其(qi)絕緣體，然后整個電纜由(you)(you)特氟綸材(cai)料的(de)護套包住。

同軸電纜由里到外分為四層：中心銅線（單股的實心線或多股絞合線），塑料絕緣體，網狀導電層和電線外皮。中心銅線和網狀導電層形成電流回路。因為中心銅線和網狀導電層為同軸關系而得名。