4 ms·

I remember the shortwave radios from decades ago. For example, a Realistic DX-390. As an amateur radio operator, I always wanted one of those that would cover

I remember the shortwave radios from decades ago. For example, a Realistic DX-390. As an amateur radio operator, I always wanted one of those that would cover every legal frequency. In a perfect world, it would also let me transmit on every legal frequency by plugging in a mic and an appropriate antenna. It should be able to let me type in my call sign, then look up it's location (GPS?) and know what my privileges were. It should be able to check the antenna before transmitting with a built-in antenna analyzer. It should be the size of my old shortwave receiver, and last forever in the internal lithium batteries when the LCD touch screen is off. Did I miss something, or is amateur radio stuck in the early 1990's? Maybe I'm too cheap to buy the good equipment.

squarefoot 3y ago
The HackRF One might be what you're looking for, although it needs a PC to operate, but fitting one in a Pelican case along with a small laptop and a battery could make an interesting thing to carry around, limited only by the software used. Once you do everything in software, you can decode digital modes, read GPS location, fill in log entries, etc. https://greatscottgadgets.com/hackrf/one/ https://greatscottgadgets.com/hackrf/one/
- RecycledEle 3y ago
  The HackRF One seems to bottom out at 1 MHz, which is not ideal for SW listening. It's ceiling of 6.3 GHz is promising. It's transmit goes up to 6.3 GHz (I think.) If I could find a wide band 25W amplifier that went to 6.3 GHz that I could afford, things could get interesting. Those amplifiers tend to cost as much as a new car. It has so many noisy harmonics that the FCC would take an interest if I amplified it, and I'm not keen on building that many RF filters. I could probably control a HackRF One with a tablet, but I hate having a lot of sealed-box things in a larger box. I'd rather have components. I wonder if a Raspberry Pi or an Arduino Uno R4 would be better to run the HackRF. Someone's done it. I would like to have a small eInk display for the critical information (frequency, battery status, mode, etc.) and a larger LCD display to use when I'm actively seeking a signal. I don't get why HAM gear does not have an option to let you enter your radio operator call sign, and then look up the rest in a database to see what your privileges are. Let the database tell you who is active in your area and on what frequencies. Of course there should be a switch for totally-manual / emergency-communications mode.
  - RecycledEle 3y ago
    I found 2 radios that might serve as interesting bases for what I want. The Q900 SDR is a transceiver that ranges from 160 M to 70 CM. It's about $600, and could serve as the internals for my idea. I just want to redo the user interface so it reminds me of my teenage years listening to Art Bell on AM radio. The Malachite is a receiver only that sells for $160 in a hand-held, speaker-equipped SW radio.
jmspring 3y ago
I just saw the box that has my DX-390 in it today. I like the idea you have. Someone mentioned the HackRF One. I have one of those as well (have had it for years) but never got it to work right. Maybe it was the antenna, maybe something dumb on my part.
hasmanean 3y ago
It’s stuck. Imagine if they put the transmitter right at the base of the antenna. Then you would not need all that coax. You might need impedance matching to make the antenna resonant but that’s all and it could be done continuously.
- genewitch 3y ago
  the antenna is outside and transmitters use electricity (and sometimes a lot). I've also heard hams opine that coax should be replaced with fiber optic cable, just "put the amp on the antenna" as if amplifier ICs aren't finicky enough we can put them outdoors with constantly changing humidity and pressure...
  - dezgeg 3y ago
    That's how modern 4G/5G base station equipment works; with the antenna panel and electronics in one unit.
    - genewitch 3y ago
      I haven't seen any, yet. All the celltowers around me have the gas-filled heliax running up the tower, one for each panel up top. I know that it exists as i have outdoor 802.11 and LTE panels that only need POE, but compared to the 4g/5g antenna sizes they're miniscule.
      - dezgeg 3y ago
        Interesting; they are pretty common here, although ofter paired with a passive antenna for 3g/4g, like this: https://mt-tech.fi/wp-content/uploads/2020/05/image.png.webp https://mt-tech.fi/wp-content/uploads/2020/05/image.png.webp
wkat4242 3y ago
It's not really stuck. SDR-based radios are now commonplace especially for HF. Digital radio is now a thing. What is kinda stuck is that most of these things are just commercial developments. Icom with D-Star (though they whitewash it with a whitepaper from a Japanese amateur group), yaesu with C4FM. DMR and P25 are completely commercial based. What I miss is real amateur driven research and modes, protocols and gear. There is some (eg codec2) but it's all pretty limited. And the various protocols really fragment the digital radio landscape.

squarefoot 3y ago

The HackRF One might be what you're looking for, although it needs a PC to operate, but fitting one in a Pelican case along with a small laptop and a battery could make an interesting thing to carry around, limited only by the software used. Once you do everything in software, you can decode digital modes, read GPS location, fill in log entries, etc. https://greatscottgadgets.com/hackrf/one/ https://greatscottgadgets.com/hackrf/one/

RecycledEle 3y ago
The HackRF One seems to bottom out at 1 MHz, which is not ideal for SW listening. It's ceiling of 6.3 GHz is promising. It's transmit goes up to 6.3 GHz (I think.) If I could find a wide band 25W amplifier that went to 6.3 GHz that I could afford, things could get interesting. Those amplifiers tend to cost as much as a new car. It has so many noisy harmonics that the FCC would take an interest if I amplified it, and I'm not keen on building that many RF filters. I could probably control a HackRF One with a tablet, but I hate having a lot of sealed-box things in a larger box. I'd rather have components. I wonder if a Raspberry Pi or an Arduino Uno R4 would be better to run the HackRF. Someone's done it. I would like to have a small eInk display for the critical information (frequency, battery status, mode, etc.) and a larger LCD display to use when I'm actively seeking a signal. I don't get why HAM gear does not have an option to let you enter your radio operator call sign, and then look up the rest in a database to see what your privileges are. Let the database tell you who is active in your area and on what frequencies. Of course there should be a switch for totally-manual / emergency-communications mode.
- RecycledEle 3y ago
  I found 2 radios that might serve as interesting bases for what I want. The Q900 SDR is a transceiver that ranges from 160 M to 70 CM. It's about $600, and could serve as the internals for my idea. I just want to redo the user interface so it reminds me of my teenage years listening to Art Bell on AM radio. The Malachite is a receiver only that sells for $160 in a hand-held, speaker-equipped SW radio.

jmspring 3y ago

I just saw the box that has my DX-390 in it today. I like the idea you have. Someone mentioned the HackRF One. I have one of those as well (have had it for years) but never got it to work right. Maybe it was the antenna, maybe something dumb on my part.

hasmanean 3y ago

It’s stuck. Imagine if they put the transmitter right at the base of the antenna. Then you would not need all that coax. You might need impedance matching to make the antenna resonant but that’s all and it could be done continuously.

genewitch 3y ago
the antenna is outside and transmitters use electricity (and sometimes a lot). I've also heard hams opine that coax should be replaced with fiber optic cable, just "put the amp on the antenna" as if amplifier ICs aren't finicky enough we can put them outdoors with constantly changing humidity and pressure...
- dezgeg 3y ago
  That's how modern 4G/5G base station equipment works; with the antenna panel and electronics in one unit.
  - genewitch 3y ago
    I haven't seen any, yet. All the celltowers around me have the gas-filled heliax running up the tower, one for each panel up top. I know that it exists as i have outdoor 802.11 and LTE panels that only need POE, but compared to the 4g/5g antenna sizes they're miniscule.
    - dezgeg 3y ago
      Interesting; they are pretty common here, although ofter paired with a passive antenna for 3g/4g, like this: https://mt-tech.fi/wp-content/uploads/2020/05/image.png.webp https://mt-tech.fi/wp-content/uploads/2020/05/image.png.webp

wkat4242 3y ago

It's not really stuck. SDR-based radios are now commonplace especially for HF. Digital radio is now a thing. What is kinda stuck is that most of these things are just commercial developments. Icom with D-Star (though they whitewash it with a whitepaper from a Japanese amateur group), yaesu with C4FM. DMR and P25 are completely commercial based. What I miss is real amateur driven research and modes, protocols and gear. There is some (eg codec2) but it's all pretty limited. And the various protocols really fragment the digital radio landscape.