Duba wurin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar yadda wurin yake:  Hanyar wucewa: Matsanancin tsangwama a gefen da ya fi tsayi na zangon mita 150 <unk> 200 <unk> tsayin raƙuman ruwa na hukuma da aka ba wa masu sha'awar ta Babban Taron Rediyo na Kasa na biyu a 1923 <unk> tilasta masu sha'awar canzawa zuwa gajere da gajerun raƙuman ruwa; duk da haka, masu sha'awar sun iyakance ta hanyar tsari zuwa raƙuman ruwa fiye da mita 150 (2 MHz). Wasu 'yan sa'a masu son da suka sami izini na musamman don sadarwa na gwaji a tsawon raƙuman ruwa ƙasa da mita 150 sun kammala ɗaruruwan hanyoyin sadarwa masu nisa a kan mita 100 (3 MHz) a cikin 1923 gami da farkon hanyoyin sadarwa na transatlantic. Zuwa 1924 ƙarin ƙarin masu son masu lasisi na musamman suna yin lambobin sadarwa na yau da kullun a nesa da nisan mil 6,000 (kilomita 9,600) da ƙari. A ranar 21 ga Satumba 1924 da dama masu son a California kammala biyu-hanyar lambobin sadarwa tare da wani mai son a New Zealand. A ranar 19 ga Oktoba, masu son wasan kwaikwayo a New Zealand da Ingila sun kammala minti 90 na tuntuɓar juna kusan rabin duniya. A ranar 10 ga Oktoba, taron Rediyo na Kasa na Uku ya ba da damar yin amfani da igiyoyin gajeren zango guda uku ga masu son Amurka a mita 80 (3.75 MHz), mita 40 (7 MHz) da mita 20 (14 MHz). An rarraba su a duk duniya, yayin da aka kirkiro band na mita 10 (28 MHz) ta taron Washington na Radiotelegraph na Duniya a ranar 25 ga Nuwamba 1927. An buɗe zangon mita 15 (21 MHz) ga masu son a Amurka a ranar 1 ga Mayu 1952.  Tambaya: Sau nawa aka yi bands na gajeren zango?
uku