按键电话机
push-button telephone set
KTU Key Telephone Unit
按键电话适配器
KTA Key Telephone Adapter
Key Telephone Adapters KTA
脉冲按键电话机
impulse push key phone set
按键自动电话机
push-key automatic telephone set
市内电话电话号码配换选号
Selection or Change of Telephone Number
电子键电话服务
electronic key telephone service
《陆海军联合无线电话电报规程》
Joint Army and Navy Radiotelegraph and Radiotelephone Procedure
帮流电话电路
booster telephone circuit