During a seven-day auction on eBay that ended on May 29, Novocin says he sold four items, including an X-Band Weather Radar Modulator for and a high-frequencyradio circuit card for .
The operating band of an individual antenna covers e. g. the frequency range used by a radio system or only the transmitting or receiving band in that range.
单个天线的工作频带覆盖了例如由无线电系统所使用的频率范围或者只是该频率范围内的发射频带或接收频带。
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Short wave is radiofrequencyband earliest utilized by human being, and short wave communication is one modern communication method with a long history.