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Comment by exar0815 | Hacker News Reader

This looks like a cool device for people just starting with electronics.

Slight OT: Its really sad to see that even though SDR really took off in the last couple of years, there really is no open source or at least low-cost toolchain for RF Engineering. No Signal Generation Hardware, no VNAs, no SAs... Mostly you have to make do with the still pretty expensive, 90s-Legacy devices of the large brands (Agilent/HP/Keysight or Rohde&Schwartz). Its also really stuff that Makerspaces and FabLabs are completely devoid of. Software is not much better, when you dont want to resort to unlicensed copies of the professional tools. Really hard to work on stuff like that when not either at a university or employed in that field...

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On the plus side, those legacy devices are orders of magnitude better than anything that a beginner could build and can be bought relatively cheap through surplus stores.

Not sure if anyone in here subscribes to The Signal Path [1] on YouTube, but he does tons of teardowns (and repairs!) of RF/signal processing hardware new and old. You'll see precisely what jaquesm is talking about. The marquee specs might not look so great on paper, but you'll find absurd levels of craft and attention to detail in some of that older equipment.

[1] - https://www.youtube.com/user/TheSignalPathBlog

Love watching the signal path, especially the pooch appearances :)

High dynamic range (i.e. low noise figure, high linearity, and especially shielding) and low phase noise will always be expensive. They are independent of software and Moore’s law.

The design software is not cheap either, as typical software skills are only 1/3 the knowledge required to develop that stuff. Also need circuit theory, EM, scientific computing, etc. There will probably never be an open source equivalent.

I have an RF/Microwave lab at home with HP VNA, spectrum analyzer, power meters, signal generators, and Tek scopes and curve tracer. Also Microwave Office and Altium.

Yes, that stuff is expensive, but has also never been cheaper to buy. An 8566B spectrum analyzer can be had for $2k, and is far better than shit from Rigol. That 8566B cost $85k in 80s/90s dollars.

There will probably never be an open source equivalent.

That may be a little pessimistic. QUCS development seems to have stalled, but they were certainly on the right track.

Given the kind of sponsorship that, say, KiCad enjoys from CERN, I would expect some pretty awesome RF engineering tools to emerge.

QUCS is nowhere near equivalent to Microwave Office or ADS; those each have well over 100k man-hours of code development. Harmonic balance, transient for distributed circuits, envelope and system simulation, layout, 2D and 3D EM, and hundreds of models, all tightly integrated. Not to mention all the MMIC and RFIC PDKs.

It’s fine for hobby use, but if you need to make $ and get designs out the door, you need to use the real stuff.

I tried KiCad, but using Altium for 25 years, it just doesn’t have the functionality I need. Lacks basic things such as assigning nets to arbitrary polygons, which is a must for RF.

Is QUCS the current best open source equivalent? I used to do hardware long time ago and might play around again as a side project.

The ARRL has a quarterly publication, QEX, that frequently publishes FOSS hw/sw designs for VNA, spectrum analyzers, and frequency synthesizers.

http://www.arrl.org/this-month-in-qex

American Radio Relay League (ARRL)

Very complicated web site that a defense contractor would love. But definitely worth looking into. Wow.

I vaguely recall this group as serious ham radio people who know how to keep communication going even when disaster might take down other networks. We have other technical volunteer groups out here, like Search and Rescue, first aid and so on.

I would have thought there would be a big central repository of Gnuradio models that cover all of the basics at this point--think Thingiverse for SDR--but I've never found it.

Maybe people are worried about the liability if some complete noob with a LimeSDR board starts jamming police radio bands or something?

When the LimeSDR Kickstarter was underway, one of the selling points was launching an app store based on Snaps on Ubuntu, I think this is the current version of that [1], which seems a bit empty to me.

GNURadio does also have a store directly for it called PyBOMBS [2] as well, though it is unfortunately not included by default, and it has been a few years since I checked it so I don't know how much it has.

Gnuradio is a bit overcomplicated at this point also, using both Qt and GTK, and a long list of other dependencies.

Luaradio[2] is quite nice as an alternative, and is much easier to embed into an end application as Lua itself is very good at that kind of thing.

[1] https://limenet.snapcraft.io/ [2] hhttps://github.com/gnuradio/pybombs [3] http://luaradio.io/

No. 2 takes a while to setup IIRC. It isn't really click to run. Though once it's setup it's pretty straightforward to use. AppImage, snapcraft etc. would help a lot here.

That was the same thoughts I had on gnuradio + a cheap sdr.

I remember I tried to get a temperature sensor decoding gnu radio plugin working and I never solved it.

Couldn't run it on a Pi, it required a fast intel system to be usable. That eliminated the nice raspberry pi "canned image" solution other projects use to cut through the dependency mess.

So I had to do a linux installation from scratch.

But the online packages for gnu radio were broken or out of date.

So I had to build GNU radio from scratch.

And once I got GNU radio going any existing gnu radio program was broken because it required an exact version of gnu radio and other dependencies.

Maybe it is better now, that was a few years back.

I've also come to see the light with Arch Linux, so that might help.

Higher barriers for entry may be good for SDR. If it were too easy there may be problems with inexperienced or inexperienced+nefarious people causing problems. Spectrum is a limited resources and it is fairly easy to poison the well.

If that happened too much regulators might tighten up and make it impossible to do (or sell) any SDR.

The barriers are exceptionally high though. I have a degree in Physics as well as a degree in Electrical Engineering with a specialization in RF from a well-regarded engineering program and wasn't able to find any jobs in the field. In SW engineering, I am able to get offers for high paying jobs inside of a month.

I feel like I would be able to get an RF job much more easily if I could build a portfolio like I did for SW. It's a moot point by now probably; I'm already getting paid more than the average general practitioner while being able to work from home 100% and wouldn't want to revert to lower pay while being stuck in a cubicle all day.

redpitaya [1] makes an nice modern SDR transceiver. [1] https://www.redpitaya.com/

You can get by with an oscilloscope and function generator both of which have gotten a lot better. A lot of homebrewing aims at using those devices. This is in the HD worls.

What about LimeSDR?

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