Hackaday Prize Finalist: A Portable SDR

No other project to make it to The Hackaday Prize has people throwing money at their computer screen hoping something would happen than [Michael Colton]’s PortableSDR. It’s a software defined radio designed for coverage up to 30MHz. Amateur radio operators across the world are interested in this project, going so far as to call this the first Baofeng UV-5R killer. That’s extremely high praise.

[Michael] was kind enough to sit down and answer a few questions about how his entry to The Hackaday Prize has gone. You can check that out below, along with the final round video of the project. Anyone who wants their own PortableSDR could really help [Michael] out by taking this survey.

What was the inspiration for this? Was it just a desire to build
the radio you wanted, and doing something with SDR, or was it 
something deeper?

It wasn’t really a single moment of inspiration and I don’t know that it was that deep. It evolved. I first learned about SDR radios reading this article by Gerald Youngblood. I was blown away that such a thing existed! A radio that could basically do anything!? I wanted to have one, but couldn’t afford it, I’d need to build my own. So I reread the articles several times and studied the schematics until I pretty much understood how every part worked. He didn’t supply a Bill of Materials, so I reconstructed one. I didn’t know how to layout PCBs back then either, so I started learning Eagle a little. But life got busy, other things came up and I never recreated his radio. As I improved in skill, and in particular got better at working with microcontrollers, I started to think that I could simplify some of his design (he’s got a whole board of shift registers to allow a PC parallel port to control everything). About a year ago I got into ARM chips that had raw power, built in DACs, and DSP libraries! I started to think that one of these chips could do it all. So now I could take out the computer, and if I could do that, I could make it portable, and suddenly it was even more appealing to me than it had been to begin with! Combine all that with my interest in ultralight backpacking and in ergonomics, and that’s how the concept of the PortableSDR was formed.

By this point, I had developed some degree of skill at PCB layout  and started making progress on the design. I hadn’t done much yet when I saw this and part of me said, “I’ve been wanting to do this for years and he just knocks something this cool out in a few days!? I’ll show him!” I actually emailed back and forth with Rich for a while. Then the Hackaday Prize was announced and I officially had the kick in the butt I needed to get something made. As much as I dislike deadlines, it really helped. With the PSDR1 there was a time where I decided a “PCB must be made, nothing else gets to be included in this version.” Same happened with the PSDR2, “this is all I get, everything else will have to be in the next one.” It forced me to build something instead of endlessly debating whether this part or that was going to work exactly right. It also helped justify spending a little money I had been saving.

You have a GPS module, and doing CTRL+F 'APRS' reveals nothing on 
your project logs. What's the timeline for that?

You’re right, not much has been done with the GPS yet. It wasn’t included APRS initially, it was to get accurate time for lower power digital transmission modes like JT65. I didn’t know there was such a thing as HF APRS. The idea of using it for emergency location came later as well. I’ve used this module in another project before, so I’m not worried about making it work, but getting other features working seemed like a higher priority, so the GPS stuff has been on a back burner. I have the TinyGPS library more ore less ported over though. I’ll probably have time and location working pretty soon. Now, writing code to encode and decode these modes is a ways off and beyond my current comfort level. I’ll get there, but given the hugely positive response I’m getting from the community, I think someone may beat me to it. I need to get more hardware out there.

A number of people have called the PortableSDR the first Baofeng UV-R5
killer, a very impressive compliment given that's everyone's go-bag 
apocalypse radio. You're producing kits, but are there any plans to move 
to full-scale manufacturing? Is that going to require a redesign, or are
you been designing for manufacturing the whole time?

Wow! That’s high praise indeed! One of the great things about the Baofeng radios is the cost, how can you not buy one! I certainly wont be able to compete in that regard. On the other hand, in a real apocalypse (I’ve heard Utah is one of the likely starting points for the zombie apocalypse, BTW) I think the range of an HF radio like the PortableSDR is going to be more useful and its handy display will make finding signals from the few scattered survivors easier. Speaking of which, I wanted this thing to be tough, for backpacking, but also because I don’t like throw-away electronics. I want the PortableSDR to be something that holds up and works well for years, which it may have to, after the complete collapse of society.

I actually haven’t really started selling kits yet. I sent all of the PSDR1 boards to eager followers of my project. At least two of which have been built up (thanks John Laur and Nricciar)! I plan on doing the same with the extra PSDR2 boards, but haven’t gotten to it. I’m going to put up a poll up on my project page. I want to know how many people want kits vs. assembled units. How many want the housing? In metal or plastic? If I do kits, are people really comfortable soldering some of these parts? A few have asked for a kit with the hard parts installed, fair enough. How many people want the PSDR2 as it is, and how many would wait for the PSDR3 (it might be a while)? I can pretty much start doing kits immediately (and plan on it, probably in the next week or two) but assembled boards and housings are going to be much more work. I did design the board and housing for manufacture, most of my design experience is from work, so it’s a habit, but I’ve never been the one that made the manufacturing happen, selected the assembly house, etc. It’s daunting. Also, it seems like 100 unit minimum orders are the norm (at least where I am looking. Hey Hackaday Hive Mind, any recommendations?!) so it might cost me $20-30,000 to start the first production run of the PSDR, and that’s not including the housing or FCC certification! I think I’ll put together a Kickstarter so I can see if there is sufficient demand to cover the costs. I would love to see these out in the wild! I really want to see if people will get involved and help make it amazing, like I think it has the potential to be. This whole process is scary, but exciting!

Hypothetical, and we’re not going to hold you to whatever answer you give.
You win the grand prize, a trip to space or about $200,000 USD. Which one
to you take, and what is your reasoning for doing so?

A question I’ve given much though to, despite my efforts not to think about it. I would truly love to go to space, and it would break my heart to pass on the opportunity, but the money would have a larger and more lasting effect on my life and family. Most of it would go to boring stuff, taxes (I think people forget or don’t know that taxes are collected on prizes! Though I did see that the space trip has some allowance for that, which is awesome and generous!), tithing, mortgage, savings, etc.

A good portion would go toward continued development (lab toys!) and production of the PSDR. Also, I think I’d take my wife to Japan and Taiwan. It’s weird, but I have a list of possible things I would spend it on, sorted by priority with pros and cons.

If it were orbital, would that make a difference? I’ve thought about that too. I have to admit, a week on the ISS, for example, might be more tempting than I could bear. But then again, someone commented that getting to and staying on the ISS would cost something like $50M. In that case, I’d still have to take the money!

Anything else?

I’ve got some stiff competition! I’ve been following the other four and I really like them all! As I watched their videos, I couldn’t help but be conflicted, I hope I’m the one who wins, but their stuff is awesome! They have all worked hard, done amazing work, and any one of them deserves to win. I’m really grateful to Hackaday and the Evil Overloads for putting this on, it’s spurred on some amazing projects and has been a ton of fun. I hope Hackaday continues to feature other projects that came out of the competition. And thanks to everyone that’s been so encouraging of my project, on my blog, youtube, reddit, even some other blogs! It’s helped me stay motivated and excited through this whole process! I’ll make cool stuff for you!

74 thoughts on “Hackaday Prize Finalist: A Portable SDR

  1. The enclosure looks beautiful! And the TFT screen is great too. I’ve used it before, but drawing animations was impossible with the slow arduino SPI speed…. This looks smooth though! And I just have to say again: that enclosure.

  2. Main short fall is tx power. I have a hackrf which imho sets the bar pretty high for this to accell . The tx power is one of the main limiters on the hackrf and existing sw backends. For this to be a baofeng killer (gawd i face palm when i see that kinda shit) it needs to hit 8w or more. I know for fact with a whip slightly over 5w is NOT enough for me to hit the repeater full quieting. I had to build an antenna to get in on 5w. I expect to try the bff8hp and see if 8w does the trick. Personally for me I believe 10w would be my target. That beats baofeng and with out doing that this will be as much a baofeng killer as the chipkit was an arduino killer.
    Split on how to answer the “would you buy a first rev” basically I dont want something that is as low power as my hackrf, I already have a 400$ sdr that does that. But I would seriously consider it if the price was right. Again , this has less freq range than the hackrf, so with the same limitations to tx power imho the wise money is in the hackrf. This really is a deal breaker for me. 10w is a good target as i can get something like a elecraft amp with tuner for about 1k. 10w should imho get people into repeaters fine, atleast when comparing to baofeng. Would I pay 3-400 for something that barely beats a baofeng, with SDR, waterfall, etc… Yes. But if I got a first rev the only reason i would is to set it on a shelf and hope for something more useful.
    If finished right, this will revolutionize amateur radio. If not it will run the course of everything else called a XXX___XXX killer.

    1. 10W is overkill. The beofeng operates at 3-4w and this is plenty for most people. As tx power increases the design becomes significantly more complicated and expensive. I would hate to see the design get side tracked trying to meet a goal not even available in most commercial handhelds.

    2. What’s great about the capitalist system is, you have freedom
      of choice how to spend your hard earned money. Don’t want to
      buy this nifty device ? Then you are free to pass on it. I for one
      will happily purchase the kit when it becomes available.

      You ever hear of “QRP” ? or “WSPR” ? (we’re talking milliwatt
      levels). I’ve done plenty of QRP CW on both my FT817 and KX3.

      And you do realize this is an HF radio right ? (as in – what
      repeater are you trying to access with this Portable SDR ?
      when it’s not designed – yet – to work on uhf/vhf repeaters).

    3. It’s an HF radio, not VHF or UHF. So you’re not going to be hitting any repeaters with it, regardless of its power. But low power on HF can go great distances, especially with CW and digital modes. A couple of watts will work the world. Sure, higher power can help in some circumstances, but if you need higher power, and can tolerate the greater battery demands, you can always tack on an amp.

      This is not in the same market niche as the UV-5R, and not a direct competitor.

      73 de Rich/AG6QR

      1. This is a good point though and my reasoning is this:
        I dont have the ability to put up nice antennas as I am in an apt. Mine is sitting on the desk next to me.
        It plays into my feedback because to be a baofeng killer you need to actually be comparable to a baofeng, and probably do what it does. It implies it does 2m/70cm imho so dont tar me up because the comparison was made in the post.
        Granted Im a new ham myself but baofeng to me (owning one) means 2m 70cm dual band , I saw one 220 too I think. It also means advertised 5w in most cases h/p. How could you possibly compare an hf rig like this?

        1. PS Never seen a baofeng do cw (has one?). Though I do play with digital modes with success. Just noted due to repeated references to qrp cw. If we are thinking of revolutionizing ham radio (read baofeng killer by hipsters) than defaulting a debate about a new radio design to “Then do qrp cw” or “This is hf” is not productive. New hams will likely have very limited access to either and baofeng is hands down the best starter radio to get a new licensee. You dont even get tested on cw so the chances a new ham (read target market to be a baofeng killer) would have very little use for a qrp hf rig as compared to what baofeng is.
          The revolutionizing SDR will incorporate all bands and all modes into a small easy to mfg package , with a useful power output , especially on bands that actually need it. IE 2m 70cm . Which if my nooby memory isnt letting me down is primarily the freq’s used by places like ares , karma, etc which baofeng do, quite well.
          Im not ripping on the project at all. I really like it. This is my 2 cents on what it takes to make the comparison made here.

          1. Yeah a Baofeng is a probably poor reference as it’s a cheap UHF/VHF FM-only hand-held, and this appears to be basically a ARM processor based SDR similar to HackRF. This might be a Flex1500 killer. I might add that if you’re planning to propagate that lat/long from your GPS digitally, you will need to include PSK or some HF compatible digital mode, (or you could always send it in CW:), If it was a Baofeng you could use APRS (if you had a TNC), which you don’t have on High Frequency

            More power to you though, I’m a major embedded systems junkie in my 41st year of ham radio, where I’m more into the antenna side of things and play with Arduino tuned magnetic loop antennas as I live in an apartment, but still communicate just fine with my Flex1500 and 5 watts of power worldwide, using CW, SSB, and PSK31.

            Even better would be to add an antenna tuner. As soon as you have a transceiver that isn’t “rock-bound”, you will be able to tune around but that wire-dipole or man-pack whip antenna is only going to resonate within a part of one band optimally. Mismatched antenna=high VSWR=low ERP and Arduino Antenna Tuners are getting to be easier to build and probably out of scope… Cool project. 73, WR7R

    4. As others have said, 5 watts is plenty on hf for digital modes. I’ve made quite a few dx contacts with psk using 5 watts (or less.) If the price is right, this product will help lower the $ barrier of entry into hf. When I first got into hf, I simply did phone until the digital bug bit me. Now I have a good bit more contacts on digital modes than phone.

    5. I think you are right that in many ways comparing the BaoFengs to the PortableSDR is not really a fair comparison. In particular, cost, power output and bands covered. Adding at least VHF to the PortableSDR is on my list (if I don’t have to compromise too much to get it) but that wasn’t really the goal of the radio. My thinking is that people would take it to places where there isn’t repeater coverage anyway.

      That said, I think the comments about this being a BaoFeng killer were more along the lines of “what radio should I throw in my emergency go-bag” in that sense, the PSDR could very well be the better choice. Or maybe “what’s the coolest ham radio I can fit in my pocket.” I’d like to think the PSDR would do better there too.

      1. Definitely agree with that and hope you can make it work with vhf. Perhaps a ‘snap on’ add on that both adds 2m and a few watts output? Definitely like this for what it is though. Its an awesome project. And probably will end up with one , Id really love to see a near all band version at some point. =D

    6. This is an awesome radio and I truly hope to get my hands on one.
      That being said, this is NOT a UV-5 killer because they serve completely different functions in completely different portions of the RF spectrum. The PortableSDR operates in the HF (below 30 MHz) portion of the spectrum. This part of the spectrum, also called shortwave, allows for worldwide radio communications with very, very little power. For instance, I have worked Perth, Australia from New Hampshire, USA, using less than 5 watts of transmit power in the 20 meter band (14 MHz). The Australian ham was also only using 5 watts.

      If Michael can get this thing to put out 3 – 5 watts, it will be golden. Even 1 watt will be plenty when conditions are good.

      Comparing this to a UV-5 is comparing apples to oranges.

    7. You shouldn’t be thinking about buying this to get into a repeater. There is enough stuff out there already to do that. This is for HF weak QRP work and fun. 5W is loads and lots of folks run with 1W. This is NOT for the 2M crowd, not even close.

    8. Maybe I’m missing something, but a uv5r and similar are VHF/uhf, this is HF. You are not going to use this to talk to a repeater. You attach this to a decent antenna and talk across the world, not the city.

      Also, each S meter ‘tick’ usually indicates a 3db increase in received signal. It takes twice the rf (or is it 4x?) energy at the antenna to get that 3db.

      And full quieting isn’t REQUIRED, you should be able to talk to a slightly noisy signal without issue. If you complain you’ll run off those who are just getting into the hobby or those who are on the other side of the state who just happened to catch a temp inversion or something.

      Now get puff my lawn.

    9. I work the world on 2.5 watts. if you are having trouble with the local repeater at 5W then your antenna has a major malfunction. Last time I went QRP on HF I talked to a guy in Iowa (600 miles away) when I was running 2.5 watts into an antenna I was only able to get a 2:1 match on it. that means my effective radiated power was 1.25 watts.

      Ham radio is 5% power and 95% antenna.

      1. Its the baofeng whip. It does have some malfunction, but my specific needs up in chicago land are it needs to hit the repeater, from inside the 5w triggers it with full bacon no signal. And that is with upgraded whip. I do agree I should be able to hit it on less than 5 and I can with the antenna I built.
        Gotta think like someone restricted to the antenna the landlord cant complain about. It was compared to baofeng. I suppose my specific needs describe why it is a horrible comparison in it’s current form / intended use.

    1. It does have voice capability. It has a built in microphone and also I designed it to use smartphone style earphone/microphones. I was hoping to make it possible to use the call button on the earphones as the PTT, but that button works by grounding the microphone. Oh well.

      The plan then is still to use that type of earphone/mic, but the morse keys will act as the PTT when in voice modes. Standard mics could work with an adapter,

  3. It’s very interesting, and the enclosure, screen, and paddles are certainly drool-worthy. It looks like the VNA hardware might be enough to completely replace an antenna analyzer like the YouKits FG-01, but there’s probably some software work to be done in that area. But of course it’s much more than an analyzer — it’s got a general coverage HF receiver with waterfall display. That’s a nice thing by itself. And it’s got a transmitter!

    I wonder if the transmitter fully meets the FCC’s spurious emissions requirements of Part 97.307? In many radios, that requires a bunch of band-specific low pass filters switched in and out.

    Currently, most digital HF work involves at least a computer, an interface box, a radio, and a pile of patch cables. It would be great to have one box do it all. Imagine the ability to compose a Winlink e-mail on the paddles and send it from this device directly.

    I’ll be watching this project.

    73 de AG6QR

    1. “Imagine the ability to compose a Winlink e-mail on the paddles and send it from this device directly.”
      Be careful with that statement, any use of Winlink is considered sacrilege to some farts :)

    2. I need to check on the spurious emissions requirements. I thought that they were relaxed for transmitters at or below 5 watts. That said, I did some recent testing on a little amplifier board and the harmonic content was awful. The next version will need to have filtering. I have an idea for a variable low-pass filter that might work without taking up tones of room. We’ll see.

      I’ll post a video tonight that talks about the initial testing of the amp board.

      1. See 97.307(d). The requirements used to be relaxed for transmitters below 5 watts, but not any more. One could make a reasonable argument that it shouldn’t matter at low enough power, but the rule since 2003 has been that spurious emissions must be at least 43 dB lower than the fundamental, regardless of power. The 500 mW Rockmite that I built a couple years ago had to have an additional filter added to meet this requirement.

  4. Why not just approach Seeed studio or Sparkfun for production instead of trying to ramp things up on your own. Seeed studio produced the DSO Nano and seem to be able to churn out new products as fast as anyone can consume them.

    1. I might. I’m totally open to things like that. Seeed studio has a production/assembly service with a little estimator, Their estimate for 100 units (the lowest volume they show) was in the $25,000-30,0000 range. Most of that is component cost, the PSDR does have some expensive parts… But maybe they give a better deal if they get to keep part of the profit. I think Sparkfun does stuff like that too. Provide the board to them and let them sell it, or let them build the board, but you don’t get as much money.

  5. My understanding of SDRs is that they tend to be a higher power draw than their dedicated component counterparts, I’m not familiar with the screen on the radio, but I can see that being low draw either… and the battery pack doesn’t look particularly large…

    Looks like a great product, but before I’d commit to it I’d want to see battery life estimates (particularly if the intended purpose is for backpacking)

    1. Now that you mention it, I don’t think I’ve ever mentioned battery life anywhere, but I have been thinking about it and have taken some measures to keep it low. Currently on receive it draws about 0.6W. It’s pretty thrifty, in my opinion. For reference, my Yaesu FT-817 (a very popular HF backpacking radio) draws 3-3.5W on receive (depending on battery voltage, among other things)

      It uses a single cell, 2000mAh LiPo. I haven’t really measured it, but battery life should be in the 10-12 hour range for receive. I have left it on overnight, so it’s at least in the ballpark. Like other radios, transmitting will drain the battery much faster. Using the GPS a lot will also effect it.

        1. But the KX3 has an 8-AA holder — assuming the obvious series configuration, 8 cells is 9.6V, so 150mA is 1.44W; much better than the FT-817, but still makes 0.6W look quite impressive.

      1. Michael – Add a solar cell add-on or put it on back of unit. I would like to be informed when the assembled version is available. If it’s reasonable I might spring for it. It sounds awesome. Is the frequency bandwidth continuous or did you lock out bands to keep it Ham only?

        1. I might add a panel to the back, but what I really thought might be cool would be a wrap around cover (like you see for tablets, that has two solar panels on it. It would keep the PSDR safe, and then could be unfolded for charging.)

  6. Great project, I would like to buy a full blown kit…solder it all myself. I think 1 or 1.2 watts out is plenty, if you want more, get an amp. Keep the aluminum box for sheilding and put an otter box or rubber case around it like a cell phone.

  7. Incredible project and GREAT product…!! I know when the PortableSDR comes out in any numbers, I’ll be in line to buy one – – LOVE THIS..!! de Marty, KN0CK (KN0CK USB dongle HF SDRs)

    1. Those tiny dongles are cool! Nice work! And thanks for the compliments on the PSDR.

      Also, I have thought about getting a custom callsign and thought choosing something that looks like a word (using the number as a letter) would be cool. I think yours is the first one I’ve seen that does that.

      1. Thanks, Mike – much appreciated…Those HF Upconverting SDRs have really been a hit with the Ham Market and I CAN assure you that you’re going to light the world on fire with your PSDR, too..! Hey, no kidding, gimme a ping by email (go over to the RTL-SDR page a click on the ‘HF’ category – look for the postings on my HF SDR dongles and link to my site and email address)…I would like to pass along a little info that may help you and get some details on your release.

        One more – it’s REAL easy to get a vanity callsign if you’re licensed already. Just get about 10 different callsigns that you’d like to apply for and do the FCC search to see if they’re used or not – some of this will also depend on the class of your license (i.e. you couldn’t get a 2×2 call if you were a General Class. You also DON’T have to be in your call district to make a vanity call. I have a friend who applied and has a vanity ‘2’ call district and he lives in Iowa that’s a ‘0’ district – the FCC allows this now. Once you have a unique call that’s not being used you can register and pay to obtain it – wait about 3 weeks for the new call and license to arrive and then you’re good to go with your new vanity call – your old call will be retired (for awhile, and then reused). Your new vanity call will be good for 10 years. Take care & 73..! de Marty, KN0CK

  8. As a ham with over 37 years of brass pounding (sending Morse code) experience this radio looks like the great-great-great- great-grandchild of the Heathkit HW-7 but with much more capabilities. The HW-7 was a kit available decades ago which was QRP (very low power) and a favorite of hams because it could be used in the field, e.g. backpacking, to make contacts on CW. It’s portability and low power was a big plus.

    Fast forward 50+ years later and now a cutting edge SDR emerges which is not only a receiver covering HF (which would appeal to SWLs – Shortwave Listeners) but also possessing the capabilities of transmitting on the ham bands. Low transmitting power? Not an issue for me or other hams interested in making low power contacts on HF but on 2m at least a half watt would be good. Let’s face it most hams will still rely on their 2m handhelds (yes I have my Baofeng GT-3 and will keep regardless) when in the field.
    Like the built-in paddle too.

    This radio intrigues me and is definitely one I’d be interested in purchasing, Michael definitely has thought of us hams when designing this rig. Hey, we hams like being first kids on the block with a new radio so bring the new technology on!

    Congratulations to you, Michael on your ingenuity and on winning the first prize!

    Mario, N2HUN

    1. Thank you very much! I have tried to put a lot of thought into how the radio will be used and what it will be used for. Sounds like I did an okay job. It’s really great to hear that people like my design.

      Congratulations on winning the first prize? I hope you know something I don’t!

  9. Love this project but disagree with people who are talking about “hitting the repeater”… the strength of this project is the SDR combined with an HF transceiver. I would love to see development of a CW reader and sender from a small keyboard plugging into the micro usb port on the side. Kudos to you Michael – 73

  10. Will CW be the only HF mode available? How about Single Sideband? SSB would be useful to both hams and shortwave listeners. Not a criticism, just curious.

    Are the components SMT? Again just curious. If it comes in kit form then will have to hone up on SMT soldering skills and avoid the hi caffeine drinks to keep the hands steady hi hi.

    I applaud the work Michael is doing, an innovative and practical product that will be embraced by many.

    The idea of this being a “Go Bag” item as mentioned in an earlier post bears merit. It would be a fun “Field Day” radio too.

    The radio would even be useful for those going mobile – in the car you could listen to shortwave stations, maybe work a few hams while parked. No need to wire the radio directly to the battery as other high power units require – definitely a plus.

    It’s got a lot of possibilities. Keep up the good work Michael.

    Great comments with great suggestions too.

    Mario, N2HUN

        1. The PortableSDR already includes SSB (and a built in microphone). As an SDR, it will be able to support any mode that is coded into its firmware (within the limitations of bandwidth and processing power). FM is not coded in yet, but will be, in especially if I am able to include VHF support.

          Also, I thought someone asked about optional filters. The PSDR has a continuously variable bandpass filter, so no need for optional filters.

          Unfortunately for some, the PSDR is not only all SMT, it’s fairly hard SMT (unless you have a microsope, flux, and a nice iron) I’m planning on making fully assembled and almost fully assembled kits. I may also make kits that have all the hard parts done already, but I think there are a lot of people that may be turned off by the difficulty. I designed it to be small, rather than easy to build.

  11. Ummm, I hear claims about hitting repeaters, but the claimed freq range is only to 30mc. My current FunCube SDR covers from BELOW the AM bcst band to over 1.2 gHz, cost a bit over $200, and as I have a ton of other stuff to do the xmtg, I think I’ll pass on this. NOW… give me an SDR that’s inside a Droid or Ipad, and we’ll talk.
    Tom – W0EAJ (it won’t make an ascii zero)

    1. Ignore the repeater talk, that was only due to the BaoFeng comparison. It sounds like you’ve got a great setup, but I would suspect that taking your FunCube, laptop, power and extra transmitters would make it less appealing for backpacking trips. That is where the PortableSDR would excel.

      That said, it would be sweet to have a smartphone that included the PSDR’s abilities. I don’t think I am up to designing a smartphone myself (yet) but a lot of people seem interested in a headless PSDR that uses a smartphone as the interface. I might do something like that when the PSDR is a little more mature.

  12. Megacycles was a common term before it was renamed megahertz in honor of Heinrich Hertz. Kinda’ like the term megacycles as it is more self-explanatory.

    A built-in microphone, that is great Michael. That is thinking ahead.

    Those tiny SMT parts are very labor intensive to solder manually. It’s frustrating but also kind of amusing to find the tiny part you are trying to solder stuck to the tip of the iron with no easy way to get it off hi hi.

    What type of antenna connector will you be using? SMA, MCX, PAL? Am already thinking of what antenna I might be using with it.

    Am also thinking that using the audio jack and feeding it into a program like MultiPSK or fldigi you’ll be able to decode RTTY, JT-65, FAX, ALE, SELCAL, PSK-31, DGPS (if sensitive enough on long wave) CW, and other digital modes. That would require a laptop or other computer but who says the radio can’t be used in the shack? It would be a fun back up/QRP rig.

    This SDR is looking better all the time! Keep up the great work Michael!

    Mario, N2HUN

  13. Nice work, but for outdoor/backpacking/disaster use it need to be substantially more weather resistant. Also not clear on the USB thing you mention attaching “keyboards” etc. so does that mean it’s OTG compatible?

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