Slashdot Mirror


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."

3 of 140 comments (clear)

  1. Re:300 mhz and up? by GrahamCox · · Score: 5, Funny

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

  2. Expansion Boards Interfaces by Nuand · · Score: 5, Informative

    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.

  3. Re:300 mhz and up? by fyngyrz · · Score: 5, Interesting

    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

    --
    I've fallen off your lawn, and I can't get up.