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by alexwwang 30 days ago
Agree.

We need a compact short wave transceiver device actually.

6 comments

QRP is the keyword you may be looking for. 9W, battery powered, SDR shortwave transceivers. There are inexpensive and expensive versions.
The antenna is the most critical part in this system. The transceiver is the second part, as to me at least.
Baofeng is 20 dollars? How much cheaper and compact do you need?

And I know, I know, Baofengs are notorious for going over the allowed noise limits… but still…

Baofeng's are not shortwave radios afaik
yes. it's a good choice for light use in UHF/VHF scenarios even communicating to satellites if you have a Yagi antenna.
Baofengs also have terrible receive filtering. It is perfectly possible to hear no stations because you are being overloaded by something on another frequency. I tried my first SOTA activation with a Boafeng. A transmitter on another hill meant I received nothing, although stains could hear me. By a Yaesu, still cheap
Yaesu FTW
yeap if you utilize "moneiability".
Is this prevented by physics or cost or just no one has the motivation?
Compact HF/shortwave radios with transmit capability exist, but they're pretty expensive and are generally definitely portable but not quite handheld. The biggest user of such equipment is the military, so a lot of the tech is engineered for that with civilian/amateur use as an afterthought. ICOM, Yaesu, and Xiegu are probably the best known makers, and you're looking at ~$1000 as table stakes for a modern one, though there are some slightly cheaper options.

Handheld CB radios do exist and are cheap, but I've never really used them.

There are a number of compact shortwave (radio amateurs prefer the term "high frequency" or HF, in contrast to VHF, UHF) transceivers. The impracticality is from the size of an efficient antenna.

I have personally made voice (single-sideband or SSB, which is analog like AM without wasting energy transmitting a carrier or redundant sideband) contacts with a 5 watt portable (Elecraft KX2) between countries in Europe, using a meter-long whip antenna and a trailing counterpoise wire.

These radios are incredibly complex weak-signal equipment, and that is reflected in the price.

That said, it is fun. Using morse code to do the same is even more fun.

I would never rely on this for off-the-grid communication, though.

A compact CB transceiver would be fun.
Fun, but short range. A quarter wave CB antenna is about 2.7 meters long. Without that, you're making more heat than radio.
wspr is known to work at 7mhz band with just cloth hanger as antenna. i think its totally possible to use headphones as shitty longwave antenna too
Someone already pointed out how the WSPR anecdotes fail for CB. The longwave reception argument is fallacy as well. There, you receive powerful signals with a poor, receive-only antenna; the typical asymmetric model of commercial broadcast radio (and cellular, for that matter.) With CB, both sides are low power. Legally, that is. And neither antenna is on a huge tower.

Several handheld CB radios exist, with little loaded whip antennas. You can go buy one. You'll see. They work for talking between two tractors in a field or whatnot. Past that, not so much. Today, you're better off with license free UHF handhelds for that use case.

Wspr is very optimised for weak signals, though. You wouldn't actually hear anything but noise.
jt8 would work. designed for ultra low db reception. We are talking here -20 dbm and chattable
There's the trusdx or the QMX.