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Developers Disclose Schematics For 50-1000 MHz Software-Defined Transceiver
Bruce Perens writes Chris Testa KD2BMH and I have been working for years on a software-defined transceiver that would be FCC-legal and could communicate using essentially any mode and protocol up to 1 MHz wide on frequencies between 50 and 1000 MHz. It's been discussed here before, most recently when Chris taught gate-array programming in Python. We are about to submit the third generation of the design for PCB fabrication, and hope that this version will be salable as a "developer board" and later as a packaged walkie-talkie, mobile, and base station. This radio is unique in that it uses your smartphone for the GUI, uses apps to provide communication modes, contains an on-board FLASH-based gate-array and a ucLinux system. We intend to go for FSF "Respects Your Freedom" certification for the device. My slide show contains 20 pages of schematics and is full of ham jargon ("HT" means "handi-talkie", an old Motorola product name and the hams word for "walkie talkie") but many non-hams should be able to parse it with some help from search engines. Bruce Perens K6BP
I've always known HT to be "handheld transceiver", none of this "handie-talkie" nonsense.
Bruce, finally something worth while. I've been reading since the beginning and this is cool. thanks for the contribution. Now more than ever.
So most commercial GPRs run in the 25-1000 MHz range. All I need to do is point this thing at the ground and it's worth $30K. Use it to measure ice thickness on ice roads, to look for unexploded ordinance, or find rebar in concrete...
This sounds like a pretty cool system to play around with. Do you need a HAM license? I assume you can use it sans smartphone?
Handroids!
Won't be long before commodity hardware can do this.
But I still won't be giving up my Elecraft KX3!
Never answer an anonymous letter. - Yogi Berra
Is there a reason this can't extend down to HF?
"National Security is the chief cause of national insecurity." - Celine's First Law
I want one*.
E
N5NEQ
*And by that I mean one per vehicle and one per office and one per home.
Most hams (including myself) are interested in HF (and others are interested in SWL and the new below-AM BCB ham frequencies.)
50 MHz means 6 meters and above -- basically, nothing that has any regularly occurring usable propagation modes. Many of these upper bands are almost dead -- I've not heard anyone on 2 meters or 70 cm around here in the last year -- but 10 through 160 meters (28 MHz through 1.8 MHz) are busy as heck, and of course all the SW spectrum in between.
Worse, we're almost certain to be about to slide down the sunspot curve, making the already mostly dead-by-choice bands completely dead-by-nature, propagation-wise.
RFSPACE's upcoming new unit is .009 (9khz) through 50 MHz. That's a lot more attractive to me. Both to use, and to support.
Then there's funcube dongle pro plus... 50 khz through 1.8 GHz, albeit without adequate filtering up front. But it's reasonably cheap, so there's that. (and I already supported it, PITA though it was, so it's not subject to the no-more-USB-devices rule.)
Well, whatever they end up with, I sure hope it's ethernet-connected and uses the standard SDR protocol as do Andrus, AFEDRI and RFSPACE. I've supported my last black sheep USB device (every darned OS has radically different USB interfacing and requirements... building my free cross-platform SDR software is most tricky with regard to USB issues. Ethernet, by comparison, is almost identical on all platforms -- the same SDR protocol / interfacing code works fine across linux, Windows and OS X.)
I've fallen off your lawn, and I can't get up.
I went through the whole presentation, and I really want one! I live in California, and we use the 1.25m band (220 MHz) a lot in my area. Nobody includes this band, even in the big expensive All-Band All-Mode mobile radios. You can get a single-band radio, but I don't drive a van or a truck, and my space for radios in the car is strictly limited. I would love to have one tri-band radio with 2m, 1.25m, and 70cm (144, 220, and 440 MHz) bands without using a transverter, and be able to do SSB on 2m. Now THAT would be a radio to have! I already have an SDR, one of the of the greatest radios on the market, the Elecraft K3, and I love it! With this I could have a fantastic mobile and another for base. Very cool! 73, WT6G
Some days it's just not worth chewing through the restraints.
This is meant to be an entire FCC type-approved transceiver with spurious emissions low enough to amplify to the full legal limit for the band. You can use it with GNURadio, but you can also run the entire system stand-alone through its on-board computer and gate-array without GNURadio. HackRF has turned out not to be a very good receiver, and is not meant to be a legal transmitter regarding spurious emissions. USRP + some daughter boards might work similarly, and have higher performance in some ways, but cost a lot more and don't have low enough power drain to go handheld.
Bruce Perens.
You will be able to do direct-sequence spread spectrum within about 1 MHz. Frequency-hopping spread-spectrum is also possible, but is limited by the speed at which the PLL locks.
Bruce Perens.
Your product line stagnated and your latest effort was seemingly launched to no end of trouble. I said this would come and now it has.
I'm really looking forward to scanners that finally have nice UIs with modern features like GPS built-in, recording, RR db access, and communities developing for them for additional protocol support.
congratulations to you and chris. do you think it would do as a base for implementing 802.22 whitespace broadband? i have a draft version of the spec available. and what would one of these boards cost?
It's really nice to see some amateur experimenters releasing the schematics for their designs again. Ever since I've been playing with radios, the scene has been very concerned with keeping designs secret. So much of the ham software is non-free (both libre and gratis), and the developers end up retiring, dying, or abandoning their work without ever releasing the code. Finding schematics for hardware is even more difficult and I've spent much of my time redesigning circuits (or reverse-engineering them from bought products or web pictures when I get stumped!).
Bruce, in your slides you mention that "The platform should be as close to Open Source and Open Hardware as possible without allowing Chinese cloners to eat our lunch – or we won't be motivated to make it." How much is this going to affect what is shared with the amateur community? Are you more concerned with making money off a product than pushing the state of the art in amateur radio. (Not that there's anything wrong with that, but there's a special circle of hell for people that see Open Source as a marketing term. Which doesn't seem to apply to you at all, Bruce, but it may still apply to this venture.)
One of the things that is holding back wider adoption of SDR is that SDR equipment from the new wave of manufacturers is often outrageously expensive for what is contained in the box. Will this be another $2000 SDR radio with $15 worth of parts inside it? (I know development costs money, but why must hams always charge for their hobby?)
If you want a vision of the future, imagine a youtube comments section scrolling - forever.
The presentation is spot on about the lack of innovation with the current big 3 ham equipment makers. Thank you for pushing the envelope in a hammy way. I'm impressed by the current crop of SDR, but it comes at a price and this promises to do more with less. Come out with a moderate power HF rig before china finally gets it's act together and spits them out....
Actually, many "smart folks like us" obtained amateur radio licenses only to leave the hobby in dismay after a decade or two. Hitting one's head against restrictive regulations just became too painful, especially the disallowing of encryption and content restrictions on carrying Internet traffic.
Until a few decades ago, an amateur license provided the operator with abilities which were totally unavailable to the unlicensed man in the street. That situation has reversed dramatically now. Wifi and cellphones far outperform almost all forms of digital communication available to the radio amateur, and they provide near-total freedom of content.
It's a very sad state of affairs, and what makes it even sadder is that the majority of old hams are in denial that this even matters. "No freedom of RF speech and we love it that way" seems to be the most common attitude among old timers. Well that just doesn't work for the younger generation who love RF but want it to be useful as well.
Today's youngsters are born into a world where the Internet is as fundamental as running water, and this places high expectations on amateur radio. It is expected to provide useful communications, not just a quaint technical passtime. "Useful" is defined by comparison to what they already have and use in their daily lives without needing a license.
The telephone shaped today's amateur radio regulations, and that antiquity shows. As a result, today's road to amateur radio is a two-way street, as not everyone stays in the hobby once it becomes clear that the old regulations are hostile to normal Internet communications. The rules are deliberately disempowering to the license holder, for whom a comms link that is not allowed to carry Internet traffic is, in 2015, about as useful as a bicycle to a fish.
50 MHz means 6 meters and above -- basically, nothing that has any regularly occurring usable propagation modes.
Moon-bounce and ham-sats occur regularly enough to be useful. Granted, hamsat passes are so short-duration and so sought-after that they aren't useful for much more than bragging rights, and moon-bounce is too technically challenging to be useful for routine communications, but they are there.
RF-based repeater networks on the 2m (~146MHz) and 70cm (~440MHz) bands are common in the United States. They offer communications over hundreds of miles without using anything but the airwaves. Ditto some mountaintop- and very-high-tower-based repeaters. A single repeater that covers a 50-mile-or-more radius is more convenient and therefore frequently more useful in an emergency than an HF-based NVIS net (NVIS is a way of setting up your HF antenna for "short range" communications of about a few hundred miles or less. Unlike typical antenna setups, they do not have any "skip", which is very useful in an emergency).
In situations where the Internet infrastructure is still up (which is almost always except during emergencies, and frequently during emergencies as well), repeaters that link to the Internet can provide worldwide communication on any band.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
What does Hamvention have to do with it?
It depends on when AMBE was introduced. Patents on math expire on the twentieth anniversary of filing.
My BITX has been in open source for more than ten years now. (www.phonestack.com/farhan/bitx.html). It has an active community that mods it, a large number of websites dedicated to it as well. It goes exactly in the opposite direction from the proposed radio. It uses very generic electronic components, it can be put together for less than 10 dollars without requiring anything beyond a soldering iron.
Open source hardware cannot mean hard to get chips, multi-layer boards and computer/phone that costs a few hundred dollars. And even after all that, the performance of this proposed rig is questionable. It has almost no strength on the front-end, the transmission is without the mandatory filters needed for the -50dbc limit on spurious emissions as per the FCC norms. The chips are not available on ebay.
The purpose of all philosophers was to impress women
Will I need a linear to jam cell signals more then 100 meters from my location? How many kW?
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Everything is shared with the Amateur community, but we have some terms that protect our land-mobile market.
The software is Open Source, but the hardware is going to be slightly less than Open Hardware, and we will be careful not to mismarket it.
It's going to start out as a $500 SDR with not enough software, and you get to write it. That is with U.S. manufacture and U.S. parts sourcing.
Bruce Perens.
If everything goes right, we will crowdfund an assembly run in a few months. But it's got to be working completely first and through a short manufacturing run. We won't crowdfund and then make you wait while we design and debug it, as some other projects have.
Bruce Perens.
I think Javier Serrano at CERN wants to fund improvements in Kicad and gEDA. I don't know enough about them myself. Chris has his favorite PCB program and I didn't force him to use something else.
But you think that's bad? The gate-array has a proprietary bitstream. You need a zero-cost but proprietary program to make it. That's the one that really irks me. We hope to work on that issue eventually.
Bruce Perens.
If we put in every feature, we'd never get done. Maybe we'll have a 0-to-SHF radio eventually.
Bruce Perens.
It was intersting to read that part of the design will be locked down, to meet FCC requirements. The celluar band lock out has never been a requirement in many countries, such as here in New Zealand. While I dont care about those bands I do wonder if it will lock out out other non-amature band uses in the name of FCC compliance, that we don't need?
For example us hams who are also like 4WD outings find that some UHF ham rigs can serve a dual role as a UHF CB, saving one extra transciever in the vehicle. In that case we are transmitting at 477MHz with a 5W limit, which while legal here would be illegal in the USA. Actully we have the reverse problem, imports from China on the USA FRS/GMRS channel being offered localy dispite being commerical frequencies here. Also it's nice to be abe to listern to commerical channels. The cheap Boefeng is great in a vehicle as it can replace 5 other radios (2M, 70cm, UHF CB, Marine and a scanner). That may not be a big deal if you have a huge Jeep but we typically use smaller 4WD such as the Suzuki Jinmy were 2 transceivers as about all you can fit.
I think an SDR such as this would be great in such an enviroment, if it could get down to 26MHz it could replace the NZ and USA HF CB rig as well allowing one box to do everything, feed it to the car stereo aux input and control it with the same Android tablet used for naviagation. It would make the ultimate communictions solution for a smaller vehicle. I really like the possiblities it opens for new modes or just embeddeding a bit of digital data in the current modes, such as the location of the transmitting station and a call sign etc.
Even as currently defined it seems like a great peice of gear, hope it goes well for Bruce.
This is meant to be an entire FCC type-approved transceiver with spurious emissions low enough to amplify to the full legal limit for the band.
Does being FCC Type approved mean there are certain frequency bands that are verboten? In other words, is the coverage continuous from 50mHz - 1gHz or are there required gaps?
I know that communications receivers capable of covering the cellphone bands were made illegal to sell in the US a while back. Just wondering how SDR will deal with such legislation going forward.
This may be a real concern where a SDR may cover bands where things like cellphones and police/military/air communications live and are heavily regulated and some portions restricted from even reception by unauthorized persons. Aren't many trunked police/fire/EMS radio systems in the 800mHz band, or is that dated? It's been a long time since I held an amateur radio license.
Strat
Progressivism (aka US 'Liberalism'): Ideas so good they need a police/surveillance-state to enforce.
I find it fascinating that everyone now carries a digital spread spectrum, full duplex device. When I was a kid, messing with (yes) 11 meters, and later graduation to ham, this was a fantasy from sci-fi. When the first brick cell phone came out, hams had already been "phone patching" to local repeaters for years. Try to explain to someone why they can or cannot get a signal, basic propagation knowledge, and you get a blank stare. No one has a clue how any of this works. We have seen Heinlein's Law in my lifetime !
The receiver has a block on certain cellular frequencies in the 800MHz band. This is the only restriction. The radio can tune to any frequency between 50MHz-1000MHz, otherwise.
To get optimal performance, you do want to have an appropriate bandpass filter in the filter bank (you can set 4 bandpass filters). They can be swapped by you to get good performance on whatever band you care about.
Testa KD2BMH
I'm not releasing this design under a 100% Open Hardware license (No gerbers, No project files). There will be a very detailed service manual with schematics and description of how the device works, like a Heathkit manual. To advance the hobby, I want to explain to everyone how a device like this works, and what Sound Engineering means in practice when building a transceiver. Giving someone Gerbers doesn't teach them these things.
No components in the design are under an NDA, and the board has LOTS of test points, so it should be very possible for the homebrew ham to modify the board to their heart's content.
All of the source code (FPGA, ARM uClinux, smartphone Android) is already up on github with an Open Source license. One part, the cellular-lockout gateway will not be Open Source. This is so that way we can actually sell the device as Amateur/Commercial equipment, not just test equipment.
I originally wanted 100% Open Hardware, but the business model doesn't work well with the FCC. It's taken me time to accept that. I chose to work with Bruce because he's an expert on how to get commercial entities to work with Open Source. If there's a chance that we could actually move to more Openness in type safe transceivers, this is a good next step to make.
Testa KD2BMH
The PSDR is a cool kit; I'm glad it had the Cinderella Story and met the funding goal in the last few hours.
I've been working on the Whitebox project since before the PSDR; None of the kickstarter SDRs existed when I started my project... The reason why I'm taking longer to launch is that our design is going to be legal to transmit with amplification; and have a fully fleshed out receive chain. This is a tall order to achieve, but we're getting close.
Testa KD2BMH
I am afraid that's not the way it works. Public-key encryption doesn't really give you the capability to decode the communication of two other parties unless you get the secret (rather than public) key, which they have no reason to give you. There is also a session key that is randomly generated and lives only for the duration of the connection, and there is the potential for VPNs or tunneling that further obscure the actual communication. It's actually very difficult for a monitoring station to even get 100% of the packets reliably, although the two stations in the communication do get them. So you may not be able to reconstruct all of the bits in the stream, and this will break decryption too.
All of this adds up to so many technical hurdles that in practice you have to be NSA to decode the communication, hams who are attempting to self-regulate will not have the appropriate resources.
Bruce Perens.
The receiver has a block on certain cellular frequencies in the 800MHz band. This is the only restriction. The radio can tune to any frequency between 50MHz-1000MHz, otherwise.
Is this block implemented in software or hardware? Could it theoretically be bypassed/removed by someone technically oriented?
Strat
Progressivism (aka US 'Liberalism'): Ideas so good they need a police/surveillance-state to enforce.
We implement it as a chip that intercepts the serial bus to the VFO chip, and disallows certain frequencies. On FCC-certified equipment we might have to make that chip and the VFO chip physically difficult to get at by potting them or something. This first unit is test-equipment and does not have the limitation.
Bruce Perens.
I've been following this project for a while, and there seemed to be little new information since Dayton 2013.
Kits or fully populated boards would be awesome.
Lets do it, and get the volume up, maybe the price can come down.
The case selection was so that we'd have at least one case that would work. We did not take much time on it. We'd be happy to have other people designing and selling cases.
The version after this one requires cases that look like real radios. That is going to be a bigger problem. We don't yet have a mold-design partner, etc.
Bruce Perens.
Hi AC,
Matt Ettus has a story about a Chinese cloner of the USRP. The guy tells Chinese customers that it is illegal for them to buy from Ettus, they must buy from the cloner instead. Then, when they have problems and require serivce, he tells them to get it from Ettus. Who of course made nothing from their device sales and can not afford to service them.
This is not following the rules of Open anything. It's counterfeiting.
So, sometimes it is necessary to change the license a little so that you will not be a chump. I discussed the fact that the hardware is fully disclosed but not Open Hardware licensed with RMS, the software is 100% Free Software, and there is a regulatory chip you can't write. We can go for Respects Your Freedom certification that way..
I've paid my dues as far as "Open" is concerned, and Chris has too. This is all we can give you this time.
Bruce Perens.
We implement it as a chip that intercepts the serial bus to the VFO chip, and disallows certain frequencies. On FCC-certified equipment we might have to make that chip and the VFO chip physically difficult to get at by potting them or something. This first unit is test-equipment and does not have the limitation.
My main interest in this SDR project would be as part of a home-brew RF/digital test/research bench for a variety of mobile cell-based equipment and development of new types of devices for new uses.
How does a company like Harris Corp. get away with manufacturing/selling Stingrays for use in the US, and can this project possibly use the same technical exceptions used by Harris Corp. to negate the requirement to artificially cripple it?
Strat
Progressivism (aka US 'Liberalism'): Ideas so good they need a police/surveillance-state to enforce.
That's excellent. Did you build your own protocol, or did you use the mechanism RFSPACE, Andrus, AFEDRI and the various USB-to-Ethernet servers have established?
I try -- hard -- to support all ethernet based SDRs for which I can obtain protocol information.
Sound card I/Q is no problem for SdrDx -- that gets the RF in, and of course I support that. The problem with the rest is controlling the SDR's settings: center frequency, attenuator, sample rate, and so on. This is because of the radical differences in USB interfacing from platform to platform.
Having said that, if you've got a working command line utility that talks to the control systems on your SDR, then SdrDx emits information via TCP that can be used to drive the command line client from a script. We've pulled this off with the Peabody and Softrock SDRs pretty well. Again, though, we run into the issue of which platform(s) the utility is available for, seeing as how they'd have to be radically different from one another.
I've fallen off your lawn, and I can't get up.
Test equipment is allowed to transmit and receive on those frequencies. If it looks like a radio, it can't. I have a number of cellular testers hanging around here that can act like base stations, mostly because I buy them used as spectrum analyzers and never use the (obsolete) cellular facilities. Government has different rules regarding what it can and can't do in the name of law enforcement, although FCC has been very reluctant to allow them to use cellular jammers.
If you can afford it, something from Ettus would better suit your application.
Bruce Perens.