Group Kickstarting a High-Bandwidth Software Defined Radio (SDR) Peripheral

TwineLogic writes "Many Slashdot readers have been enjoying the availability of $20 USB radios which can tune in the range of 50MHz-2GHz. These devices, while cheap, have limited bandwidth (about 2MHz) and minimal resolution (8-bit). Nuand, a new start-up from Santa Clara, wants to improve on that. Their Kickstarter proposal for bladeRF, a Software Defined Radio transceiver, will support 20MHz bandwidth and 12-bit samples. The frequency range to be covered is planned as 300MHz-3.6Ghz. In addition to the extended spectrum coverage, higher bandwidth, and increased resolution, the bladeRF will have an on-board FPGA capable of performing signal processing and an Altera processor as well. SDR hobbyists have been using the inexpensive receivers to decode airplane data transmission giving locations and mechanical condition, GPS signals, and many other digital signals traveling through the air around us. This new device would extend the range of inexpensive SDRs beyond the spectrum of 2.4GHz Wi-Fi. In addition, the peripheral includes a low-power transmitter which the experimenter can use without needing a 'Ham' license."

Comments

300 mhz and up?

[fyngyrz]

Mmmpf. HF is where all the fun is. :)

Re:300 mhz and up?

[GrahamCox]

Do you know how hard it is to make a stable 400 millihertz oscillator?

Re:300 mhz and up?

[fyngyrz]

The thing you need to know about those sticks is that they are *really* prone to overload and various nasty IM-like failure modes. Fun, you bet, but you kinda get what you pay for there. If you want them to work well, you'll spend ten times the effort on filters in between the antenna system and the unit in most install situations. In a really rural area you could get away with it, as everything is (relatively) weak then.

Best one out there right now is about $200 US, it's the FUNcube pro+ dongle. That's near-0 through about 2 GHZ, so you get LF through L band, IIRC. Still has some overload issues (not awful, but not what you'd really want, either), but for two hundred bucks, ya can't beat it.

-- Not associated with the FUNcube folks either, other than my (free) SdrDx software supports it.

Re:300 mhz and up?

[fyngyrz]

LOL. What is the use of that for a non-Ham?

LOL. Well, let's see. International shortwave broadcasts, both analog and digital. You know, news about other than the Kardashians. AM radio broadcasts (US and elsewhere, depending on your antenna systems.) Longwave broadcasts. Aero beacons. Military and utility monitoring. Solar flare monitoring. Monitoring ultrasonics, such as bats and insects. Submarine communications. Time stations. Citizens band. R/c device monitoring. Coast guard. Commercial marine communications. Weather reports (teletype, naxtex, FAX WX maps, greyscale satellite images.) All kinds of analysis of all of these. And yes, all kinds of ham radio monitoring too... you don't have to be a ham to listen and/or decode. There are eleven ham bands in the range 0-30 Mhz.

Just a brief overview, of course. HF is where the fun is, I assure you. I can monitor from almost DC to several GHz here, and HF is definitely where it's at as far as I'm concerned.

Re:300 mhz and up?

[TwineLogic]

International shortwave broadcasts, both analog and digital. You know, news about other than the Kardashians. AM radio broadcasts (US and elsewhere, depending on your antenna systems.) Longwave broadcasts.

It's true those are all present, but "interesting" is in the ear of the listener. None of those qualify as "interesting" in my book.

Aero beacons.

You mean like VOR? Those are up in the low 100MHz, of course...

Military and utility monitoring

Army ground is 40.5 MHz, again 40.5 > 30. Are there other military signals (we'll get to ELF in a minute)? What utility signals are below 30 MHz? I see them in the 400s around here.

Solar flare monitoring.

Ok this is a little interesting, I'll give you this one.

Monitoring ultrasonics, such as bats and insects.

Ummmmm. Those little buggers use radios?

Submarine communications.

These are on ELF, I'll give you that. But they are encrypted, of course, and they are also immune to traffic analysis. What is fun about monitoring them? Plesae don't tell me these are in the clear...

Time stations.

What is interesting or useful about this, especially given the GPS timebase being globally available?

Citizens band.

One person's interesting is another person's ridiculous, I suppose.

R/c device monitoring.

You mean 27MHz R/C? The servo signal seems particularly boring, unless you are operating the R/C device, in which case you can look at it.

Coast guard. Commercial marine communications. Weather reports (teletype, naxtex, FAX WX maps, greyscale satellite images.)

All of these are somewhat interesting, I'll give you that.

HF is where the fun is, I assure you.

I'm having more fun at higher frequencies, I assure you. I think 1090 MHz is more interesting than anything you mentioned. 121.5 is worthy of note. The 450s and 850s (public safety and government) are pretty interesting to most people. Other people enjoy trying to figure out SCADA traffic in the 400's.

My complaint with your Score-5 first post is that you are pooping on a great project because your personal interests don't align. You're a ham. You think that is interesting. Good for you. As a ham, you also have a certain "authority" with some people. That authority is misused or misplaced when you dismiss a good project on the basis of having made an engineering decision that fits the interests of others, but not yours. I am very interested in getting access to the 2.4GHz wi-fi spectrum at the level of the signal. But my interests are more in software, software security, and things like that. So this particular SDR example from RFSPACE is of pretty much zero interest to me.

Re:300 mhz and up?

[fyngyrz]

You mean like VOR? Those are up in the low 100MHz, of course...

No. I'm talking about CW format beacons. They're all below 540 kHz. Very useful to see what LW prop is going on.

It's true those are all present, but "interesting" is in the ear of the listener. None of those qualify as "interesting" in my book.

Well, sure. That's the way everything is, isn't it? I'm answering you from my perspective, because you asked me.

Are there other military signals

Yes, tons of 'em. Not just out of the US, either. You can also see spectrum probes sliding across the various portions of HF; hear mystery "coded" signals (numbers stations), even see some weird stuff that's (thus far) eluded any explanation, like slow carriers that transit the 49 meter SW band, right through the commercial stations and a very sedate and extremely stable pace. No idea what that is. Just find it interesting.

Ok this [flares] is a little interesting, I'll give you this one.

LOL, thanks.

Ummmmm. Those little buggers [bats, insects] use radios?

All you do is for your "antenna", you hook up a tweeter or a supertweeter, and hang it out by your eaves, attic entrance, etc. Feed that to the SDR-IQ. All manner of hilarity ensues. Including the lady of the house going "what, bats? We have BATS?!?!?"

What is interesting or useful about this, especially given the GPS timebase being globally available?

Well, they're also typically frequency references. You can do a number of things with them. First, they tell you about propagation (because they're always on, so you know what's on bounce by what you can hear.) You can do some cool experiments like these. They give you deep sea weather reports, too. WWVH (Hawaii) and WWV (Colorado) give you an instant tip because one uses a womans voice, the other a mans. You can tell how prop is going by what you hear. There is also BCD coded time on there. And many nations have time signals, if you know where they are (and my software does.)

[CB] One person's interesting is another person's ridiculous, I suppose.

Well, yes, exactly. CB is bloody hilarious to listen to. At least to me. And it also, because it's so busy, serves as another type of prop indicator. Even if the ham bands are dead, for instance, you can tell they are open, just not in use, when the CB bands are open.

You mean 27MHz R/C? The servo signal seems particularly boring, unless you are operating the R/C device, in which case you can look at it.

What it tells me is that it's time to go outside and check the skies for our local air club, so I find it quite useful. Think of it as a "beacon for fun." I can also tell the guys if they're making a mess - too broad, etc. Listening is not everything; analysis and reaction is interesting as well.

I think 1090 MHz is more interesting than anything you mentioned. 121.5 is worthy of note. The 450s and 850s (public safety and government) are pretty interesting to most people. Other people enjoy trying to figure out SCADA traffic in the 400's.

Ok, great. More power to you.

My complaint with your Score-5 first post

Dude, seriously, don't blame ME for slashdot moderation. It's totally broken and I've said so for years, but in any case, I didn't mod the darned post myself so I don't see how I should accept any blame for it whatsoever. Seriously. The mods here are only on crack when they aren't on meth. It's something in the perl code. Nasty stuff. As for the first post, I saw the story (twitter

Re:300 mhz and up?

[Dr. Zim]

Expressing ones opinion on the internet is like farting in a hurricane. You may feel better for a moment, but nobody's gonna care.

Wy not cover the whole band at once?

[NixieBunny]

I'm currently working on a research-grade gizmo that will digitize that entire 4 GHz wide band as one entity. It's to be used for an astronomical spectrometer. It's darn near doable today, the only problem being how to get the oscilloscope companies to shake loose a few 10 Gigasample/sec A/D chips.

Re:Wy not cover the whole band at once?

[volvox_voxel]

I have a radio astronomer friend that works on the CARMA sub-millimeter array doing signal processing/FPGA work. They use a (2) 26GSPS 3bit ADC (made by Hittite) for each orthogonal polarization for each antenna. They actually get >15 effective bits because they do averaging over 10 seconds (the SNR drops by the square-root of the number of samples). I am amazed that they can recognize hundreds of molecules, and subtitles of radio spectra with a 3bit ADC. There is a lot of interesting signal processing at CARMA. You can read about all kinds of interesting tricks to get high sideband rejection for your spectrometer bins, etc. One trick employed by oscilloscope companies [at least in the past] is to simply have a bank of ADC's, and use precision delays on the clock inputs. One ADC would see the clock pulse, the second one would see the clock that was staggered by 100ps, the next stage after that would be staggered another 100ps, and so on. You can get passive LC delay lines that are quite precise.

Expansion Boards Interfaces

[Nuand]

Hey guys, I'm John (the guy from the video). We are very excited to have made it here on Slashdot! We just wanted to post up a comment that we also left on the Kickstarter page addressing the concerns of those interested in frequencies under 300mhz. The usable frequency range of the bladeRF does indeed start at 300MHz but goes up to 3.8GHz. Having one (or even two) front-ends spanning this many octaves is a challenge, however the bladeRF performs exceptionally well over the entire range. That however may not have been the case had we included the circuitry needed to reach those lower frequencies. As a solution, we added an expansion board interface to the bladeRF. One of our first expansion boards will be a block up/down converter. We wanted to wait a little bit to get some feedback from people to see what frequency ranges people were interested in seeing. As of now it seems very likely that we will look at going from as close to DC as possible up to a minimum of 11GHz. So as soon as we do our engineering homework and see what's possible we will make an official announcement about this on the Kickstarter page.

Re:Expansion Boards Interfaces

[EmagGeek]

Have you obtained FCC type acceptance pursuant to Part 15, Subpart J of the Rules?

30 mhz and down

[fyngyrz]

For HF:

SDR-IQ (about $500 from RFSPACE or a store) and my SdrDx software (free) -- Windows and Mac versions. 14 bit decoding, USB connection to the computer, ethernet server software (free) available so you can remote the head unit.

192 kHz bw coverage from a few Hz to 30 Mhz: AM, SAM, FM, USB, LSB, CW... output to (free) decoding for SSTV, WEFAX, RTTY, Olivia, Contestia, Domino, Heil, DREAM (digital SW broadcasts), MFSK, MT63, PSK, QPSK, PSKR, THOR, THROB, NAVTEX/SITORB... pretty much you name it.

RF waterfall with palette control, RF spectrum (signal) display, independent analysis scope (RTTY, audio, spectrum, vector, 3D, Smeter/Squelch, carrier, audio waterfall)

Band markings, channel and freq ID database, auto SW station ID, point and click brick wall envelope control, multiple notch filters, TDM filtering, multioctave 50/60 hz filters, memories and memory markers, DSP noise and impulse processing, wideband recording (192 khz at a time) and playback, LPF, HPF, compatible (on the mac) with Audio Hijack Pro and Soundflower for even more audio processing goodness...

External tuning knob support, midi control surface support (to remap real knobs and buttons to other controls like volume, RF gain, squelch, blanker settings, passband edges, tuning by steps, etc.), remote antenna tuning support, remote radio control support (TCP/IP, includes example Python clients.)

SDR makes analog radio look like some very un-serious stuff. I'm listening to some hams on 3870 kHz now.

-- not associated with RFSPACE. I just write code. :)

Re:30 mhz and down

[fyngyrz]

No, the reason is that TFS says "The frequency range to be covered is planned as 300MHz-3.6Ghz.", and "12-bit samples" and this is slashdot, pal. You're bloody lucky I read TFS. lol.

And given that TFS puts the F range at "why would I be interested in that?", and the sample depth at "yawn", why would I *then* go researching more about the unit?

As for my involvement, if any SDR manufacturer wants support, I've been willing to write it free of charge. Just FYI. I've probably put as many hours into the whole SDR thing as anyone you're likely to ever meet; but the fact is, there's an entire range of capabilities out there. This one, according to TFS, falls somewhat short. If TFS is wrong... well, then, perhaps you should be pestering the person who wrote TFS, eh?

Re:30 mhz and down

[fyngyrz]

I can't help but notice that you weren't able to come up with an example of a better SDR for my application.

I can't help but notice that I didn't claim there was one. :) You do know what a "straw man" is, right?

"cuteSDR" doesn't seem relevant because I write all my own code to control the radio, demodulate (FSK/NFM) the signals, correct the parity-checked bits so the CRC matches, decode the content, etc. It's really irrelevant

CuteSDR is a great starter app that can be tweaked to work with anything. You didn't mention that you wrote your own code, just that you wanted "linux support", and inasmuch as that would mean, get ready, "software", I pointed you at the software that would support whatever hardware you wanted to run, which I had already assumed you had identified, because, get ready, you had said so. If, as you say, you write your own software, then "linux support" is pretty irrelevant, because you'll be doing the writing. I just figured you were looking for software because I'm unaware of any SDR with a "linux connector" or a "linux spectrum", ya dig? Consequently, I pointed you at something that had already done most of the difficult stuff. You're welcome, even if you're maybe kinda working a bit too hard at missing the point.

Public agencies trunked radio

I see. Something commercial, then, from the secrecy, etc. Good luck with the project.

Why you would imagine that a $20 dongle could arrive with an FM broadcast tap

"trap" -- typo, dunno if it was yours or mine, too lazy to look. A trap can be as simple as a coil and a cap, especially in this kind of setup. Small, too, at 100 MHz or so. Nothing expensive.

Are you having a bad day? My sympathies, if so. You seem to be grasping at the idea I'm your adversary. I'm not. I'm just some guy on the Interwebz.

Re:Lame

[fyngyrz]

...of which there seem to be a very large number.

Heck, there are a *lot* of brands of SDRs out there for sale. It's quite surprising, perhaps, but there it is. I own several.

The thing is, you can get far better performance out of a decent SDR than you can out of any analog radio ever made. For a fraction of the cost, and with features you could never have had.

Just think of the many radios that have sold in the past, then imagine all those people waking up to the idea that they can have tons more performance. Everything from AM radio and SW radio to ham radio and police monitoring... all for relatively cheap and *amazing* performance.

How different? You could have bought yourself an ICOM R-8000 for over ten thousand dollars... yet today, slap a little box down on your desk and *wildly* outperform the thing. For a few hundred bucks.

Every radio person I've been the first to show my SDR systems to has done the gape/jaw-drop thing. Every one. And well they should. My friend Bob told me "It seems like you're cheating" :)

Re:Lame

[fyngyrz]

SDR performance advantages: ability to dig signal out of noise. Ability to remove noise. Ability to control the bandpass. Sharpness of filtering. Ability to see what's going on around the signal, and spot signals, in unbelievably low-signal or high noise conditions -- or both. Time division multiplex filters that pull out many carriers at one time and leave excellent audio behind. Ability to ID digital signals visually in just moments... every type of digital signal has a different spectral "signature", and so I know I'm looking at Olivia, or RTTY, or SSTV, or whatever. Ability to record, and play back, entire bands. High resolution realtime carrier analysis. Ability to remote the receiver head. Precision metering. Completely reconfigurable in seconds. Direct integration with all manner of analog signal processing (eg soundflower, Audio Hijack Pro, and just about every audio plugin you ever heard of.)

Ability to get right in there and code whatever feature you want.

I had a Yaesu FT-2000, with the DMU and speaker and all the goodies. My $500 SDR-IQ wiped that thing out. On the same antenna, it could pull signals out of the noise that simply were impossible to hear at all on the FT-2000. It eliminated noise the Yaesu couldn't do a thing about, not with DSP modes and not with the blanker. The bandpass control (shift, width) wasn't even remotely comparable to the ability to drag a razor edged upper or lower bound. I sold the FT-2000 and its accessories. It was pointless, just a ton of knobs and buttons that couldn't even come close to keeping up.

I also have an FT-980, an old school analog ham radio; also can't keep up, just hears noise, mostly.

Here, the FT-2000's (presumably) greater sensitivity was useless; the noise level was too high, and it couldn't get rid of it. The SDR-IQ, plus software, eliminates the noise, so I heard much more. Then, having heard it, I can isolate it better because of the bandpass.

It doesn't do you any good to have certain types of specs unless you have a pristine signal environment. And where can most of us find that? Unless... unless you have RF signal processing that's so good as to obviate the noise. And that's what sits on my desk.

The SDR-IQ is not a top of the line SDR; RFSPACE (and others) make much higher performance ones. Yet it just kills in operation. I'd like to try the higher end ones someday. But I know from using this that an analog radio just can't get there.

I have lots of other SW radios, receive-only, also. The FT-2000 was the best receiver, but I've been collecting them for years. None of them can touch the SDR-IQ.

And finally, all this at about the cost of the high-end microphone for the FT-2000, the MD-200.

I'm not really talking about "stick" type SDRs here. You need a decent front end, and you need stable, high resolution sampling to avoid various artifacts. But if you can meet that fairly low standard, it can be an eye-opener.

Also -- like any radio -- you need to know your way around the tools you have. Given that I wrote my own, it's fair to say that I'm an expert user. But I also spent a lot of time with that FT-2000, I can tell you, and it's limits were surpassed the very first day I put the SDR-IQ on the same antenna.