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Comment by AnarchismIsCool | Hacker News Reader

I don't mean to be a downer, but I'm so fucking tired of these things. We don't need yet another way of doing AF sound card injection into shitty walkie talkies, we need an open, accessible, quality SDR transmitter that can handle digital inputs directly.

I've messed with plenty of systems like this, these antiquated radios are not designed for this and you have to spend a lot of time fiddling with the gain stages to get them to function at all. Even if you get it working, it'll still be wildly less capable than something that can do direct encoding, you lose a ton of range when doing AFSK compared to basically any other encoding scheme.

It's basically the equivalent of setting up a 3d printer gantry to hit the keys on your keyboard to send messages.

And before anyone complains, yes, I'm actively working on an open XC7Z010/AD9363 based HT for this. Essentially a Silvus but not $20k for $100 in components.

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> We don't need yet another way of doing AF sound card injection into shitty walkie talkies, we need an open, accessible, quality SDR transmitter that can handle digital inputs directly.

You might want to look into the ADALM-PLUTO [1]. The ham club I'm in uses it together with a beefy PA to make TV broadcasts to the QO-100 amsat.

[1] https://www.analog.com/en/resources/evaluation-hardware-and-...

Am I missing something or is that ADALM-PLUTO a really good deal? Its going for $195 direct from AD. Half the frequency range of a USRP but 15% of the price.

I was going to hold off on my SDR hobby until a few more gray hairs and $$$ came into my life but might need to pull the trigger on that guy (yes I know you can get an rtl-sdr for like $30).

It's only got 7 dBm / 5 mW worth of TX power. You'll still need a dedicated power amplifier or multiple - not sure, antenna/PA isn't my specialty - if you wish to communicate with anything more than a few feet away from you.

Also, its frequency range officially begins at 325 MHz. That's usable enough for the 70cm ham radio range, but practically useless for anything on the longer bands without a hack [1] that will only give you the 2m and 4m bands.

On the other hand... you don't want to go below the 2m range on a handheld anyway, antenna length can be a real pain.

ETA: WiMo sells a transverter but it'll cost you about the same amount of money that you'd have to shell out for the Pluto... and still only 50 mW of TX power. Given that our club station has a PA stage that can blast out the full allowed 750W on 160m, that's quite a difference...

[1] https://www.rtl-sdr.com/adalm-pluto-sdr-hack-tune-70-mhz-to-...

[2] https://www.wimo.com/de/dxpatrol-charon-hf-transverter-for-a...

You can also "hack" Plutos pretty easily to essentially be a USRP. The 9363 is just a derated 9361 which can go down to 70mhz, so they'll usually work if you swap the FPGA software load.

Yeah but as said going down to 70 MHz alone won't give you that many popular ham bands (at least not the ones allowed in Germany).

An SDR that can transmit down to the 160m band (1800 kHz) however... that would be practically the end of ICOM, Yaesu, Kenwood and other high-price brands.

Honestly, there are a bunch out there at similar price points to the big names, but I think the critical mass of the ham community is too geriatric to understand what IQ means and just wants to ragchew on 20m. Based on what I've seen the younger crowd is all up in the V/UHF space playing with digital radios but that's where SDR has seen the least penetration because you need something spicier than a repurposed AF ADC for the available bandwidths. I've literally seen people on reddit pleading for the ability to dump the entire 2m band at once from an HT and practically, that's pretty trivial, there's just no hardware. I'm starting to wonder if the big radio manufacturers are trying to market segment the AD9xxx/ADRV9xxx chips away from the consumers and towards to military customers. They're more expensive but you can get 9363s and 7010s for $20 ea, so total list price around maybe $500.

The pluto is the inspiration for about half the devices used in the government world. They're all just the pluto design ripped with a PA+tx switch and marked up 100x.

I feel the same way, it's incredibly frustrating how many HTs exist these days that can charge off of USB-C PD but still require these janky headset jack adapters to even do serial data transfers. There hasn't been a good excuse for lacking full native USB support for over a decade at this point. I can not explain it in any good faith way, the only logical reason I can come up with is an intentional choice to keep people buying the adapters.

I don't even care if it's just the USB-Serial aspect and not audio/SDR capabilities. Something more than just charging.

I can easily explain it.

One of the answers is cost. The chips in those radios lack usb. The USB-serial adapters are not cheap - 30c even for clones. So there’s 30c that can be cut from BOM. That’s huge when the radio sells for $20. You also need a little more circuitry around them (xtal,esd,caps), plus they consume non trivial amounts of power.

But wait it gets worse! Now that you have an interface you need to write code for it. Which is more work/time/aka $$$.

I think part of the problem is it's still difficult to find a $200 or even $1000 radio that has those features. There's a bunch of KISS TNC integration starting to happen at that price point but it's still rare and for that money you should just be able to get an IQ IO stream over USB because it's available on the uC most of the time.

>you should just be able to get an IQ IO stream over USB because it's available on the uC most of the time.

Sure, but demand isn't there :(. It requires a bunch of programming/work, and for maybe couple thousand users?

I had thought that it would be nice to have a data-only radio. Use the same SDR chip as Baofeng to make radio that has USB-C port on one end and BNC/UHF connector on the other.

Handset would with USB-C data would be nice, but I think could save a lot of complexity making a radio with no UI.

Ultimately what you're probably looking for is Meshtastic. No to minimal UI, integrates with TAC among others, can just pair to a phone and turn it into a long range p2p or mesh device for whatever use case you want.

A Pluto sdr would also work if not for micro USB. The problem is you'd need a bunch of modulation/demod software, power amp and TX/RX switch, hence the project.

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