复古收音机统治

收音机是我们最古老的电子技术。火花差距结束了，但它是真正使无线电可行的真空管和最终成功。虽然今天的一切都是用集成电路制造的，但是在许多应用中，管仍然与我们同在。无线电也仍然存在，尽管该术语变得有点复古。无线是我们更常见的更常见的术语，特别是关于世界上最复杂的双向无线电 - 智能手机。

无论如何，这里有一些例子是如何调用“旧时间收音机”的例子继续为我们服务。

世界上最长的通信距离

Does a 11.7-billion-mile wireless connection sound like a record to you? It does to me. Wow! What’s the dB path loss on that distance? It’s the approximate distance from Earth to the 43-year-old Voyager 2 spacecraft that’s far out in the space boonies. It was launched in 1977 to explore the distant planets Jupiter, Saturn, Uranus, and Neptune. Voyager continues to move even further from Earth and has, as the scientists say, gone beyond our solar system into interstellar space.

NASA lost track of Voyager 2 months ago when the only Earth station capable of talking to it went down for maintenance and repairs—namely, Deep Space Station 43 in Canberra, Australia. It took seven months to repair and upgrade the humongous 70-meter (about 230 feet) diameter dish antenna.

随着一些新的更高功率发射器和菜肴的令人敬畏的收益，DSS43能够联系Voyager 2。为航天器花了34小时的周转传播，以回应“Hello”。

This reminds us that radio’s 186,400-mile-per-second speed is just not as fast as we thought. That’s as fast as it gets. NASA credits the initial simple low-power design of Voyager for its long life. Still a good design goal. Anyway, how about that as a memorable event for an ancient technology like radio?

一个更好的音乐来源？

My son John recently told me about some of his IT friends at work and how they went about setting up to play background music in the office. They used a smart TV as the receiver and sound output source but, of course, it had to have an internet connection, Wi-Fi, and a subscription to Spotify.

开设一个帐户并设置几个播放列表后，他们终于达到了100美元/月。它从几个音乐类型中提供随机播放列表。

Subsequently, John asked them “What if I told you I could do the same thing with about $20 worth of equipment and otherwise totally free?” One guy said, “no way,” others scoffed.

The answer, of course, is local FM radio on a $20 Sony transistor radio. In some big cities, a half-dozen FM stations play music all day that anyone can access at no cost with minimal equipment. Broadcast radio. Who would have thought? Does the younger generation know about FM radio?

简单的复古无线电接收器

Not too long ago, I made up my mind about wanting to become more active in amateur radio. Yes, I admit being a ham (W5LEF). Having decided that, I realized I had little or no equipment. So, my plan was to start again with a popular ham communications specialty called QRP, meaning low power. The idea is to use minimal power (QRP is generally defined as less than 5 W) to make worldwide contacts on one of the high-frequency bands.

我选择了7.0到7.3 MHz的40米火腿乐队。对我来说是一个良好的起点是先建立一个接收者。在一些搜索之后，我发现了指定NE / SA602的复古无线电芯片中的大量兴趣。它最初由飞利浦半导体（现在北方州）在20世纪80年代的某个时候开发。有一个改进的后续芯片，称为SA612。

The 602 IC contains a Gilbert cell mixer and a Colpitts oscillator in an 8-pin DIP. Cheap and easy to work with. The good news is that dozens of articles and other coverage are available about using the device to make a simple direct conversion radio.

Direct-conversion radios mix the incoming signal with a local oscillator signal of the same frequency. With zero IF, the circuit is self-demodulating. The circuit directly recovers the transmitted information signal. Morse code or continuous wave (CW) is the most common mode of operation, but it does a good job on single-sideband (SSB) suppressed-carrier voice.

I dug out as many of these 602 articles I could find and located the IC datasheets online. All of the various receiver circuits were similar. I made my own version using the articles and other info.

I built my radio on a breadboarding socket. The filtered and demodulated output of the mixer was sent to an LM386 IC audio power amp and a 3-in. speaker. I connected my 67-ft. wire antenna and a 9-V battery for power and, voilà, it worked. Both CW and SSB signals came in loud and clear. Tuning is done with a reverse-biased rectifier diode (1N4007) used as a variable capacitor on the Colpitts LO.

整件事花费不到30美元。如果你有一个很好的垃圾箱，你就可以削减这一点。最困难的部分是弄清楚（称为Design？）所有输入调谐电路，用于选择性和振荡器调谐电路。找到廉价的右重电感也是一项挑战。我使用模制的轴向类型而不是风气芯线圈或制造环形。

我对收音机很满意。我完全令人惊讶地做得很好。我猜测了另一个地方需要另一个收益阶段。我最终会绕过重建它或在Perf Lober或PCB上重复。我可以用它作为我的主站接收器，直到获取新的商业收音机。

There’s another retro radio for you. The 602 came out in 1980s but it’s still a top-notch IC and product. If you’re looking for a hands-on project, this is a good one. I’ve also run across versions for shortwave listening and as a VHF AM aircraft pilot-to-tower radio in the 108- to 135-MHz range. Almost all commercial ham kit radios use this design. Try it—you’ll be surprised at the effectiveness of retro.

下一个项目是一个发射机。只需提供约3到5 W的几个晶体管应该这样做。

5G收音机

所以，虽然许多复古无线电持有自己，但是当天的大无线电问题是：

• Where the heck is 5G?
• And what the devil is 5Ge?

我最近一直被问到几次5ge真的是什么。它是AT＆T的重创LTE高级Pro移动电话系统，直到AT＆T滚出更多真正的5G网站。5GE可能像一些初始5G系统一样快。有点让你想知道我们是否需要5克。当然，我们会得到它，但在较长的时间内。我猜LTE现在被视为复古。看起来复古的速度正在加速。

告诉我你的复古无线电故事。