無線模写受画装置の受信感度測定結果と保守について

機関リポジトリ HANDLE Web Site

書誌事項

タイトル別名
  • ムセンモシャジュガ ソウチ ノ ジュシン カンド ソクテイ ケッカ ト ホシュ ニ ツイテ
  • The Sensitivity Measurement and Maintenance of the Facsimile-receiving Apparatus

この論文をさがす

抄録

"The Nagasaki-maru", a training ship of the Nagasaki Univereity Faculty of Fisheries, underwent three training navigations to Ceylon, Hawaii and Australia in each of the past three years, from July to September every year. Durind these navigations, the ship received the facsimile of weather reports, hydrographic information or news mainly from Tokyo, Pearl Harbor and Canberra. some results of the study on the receiving sensitivity and maintenance of tha apparatus are as follows. 1. There are some areas near the South-West Islands at about 1,000Km from Tokyo and near the Philippine Islands at about 2,000Km where the receiving sensitivity is very low with much noise and jamming in the F4 wave. This tendency is most remarkably revealed at about 1900 hours. 2. In a middle-sized ship, any receiving apparatus of higher quality than the NXA-340A type will be sufficiently practical even at a distance of over 10,000Km from Japan. 3. The F4 wave often undergoes much modulation caused by other waves showing little sharpness in the record even when the electric strength is large. 4. The time lag of synchronous signals is often caused by the variation of the electric source frequency due to over-load and by the maladjustment of the holder belt for the record pin.

1. 東京より1,000～2,000km前後の地域において波長の長い方のF4電波に混信雑音が多く,波長の短い方では感度が弱く時には非常に悪い結果が出た. それは19時頃が特に顕著である. 2. 中型船においてもNXA-340A型以上の性能の受画装置を装備すれば,本邦より10,000km以上の遠距離においても充分実用性がある. 3. F4電波は他波による変調を大きく受け,電界強度は高くても記録にシャープ性がない場合が多い. 4. 同期信号のズレは過負荷による電源周波数の変動と,記録針保持用ベルトの調整不良に起因することが多い様である.

長崎大学水産学部研究報告, v.22, pp.109-114; 1967

収録刊行物

詳細情報 詳細情報について

問題の指摘

ページトップへ