BITX, A Return to Hackers’ Paradise

bitx

[Bill Meara] has finished up his radio. It both looks and sounds great. It was only a few weeks ago that [Bill] posted a guest rant here on Hackaday. The Radio he mentioned building in the rant is now complete. The transceiver itself is a BITX, a 14MHz Single Sideband (SSB) radio designed by Ashhar Farhan VU2ESE. Ashhar designed the BITX as a cheap to build, and easy to tune up transceiver for radio amateurs in India.

By utilizing parts easily sourced from scrapped TV sets, the BITX can be built for less than 300 Indian Rupee – or about $4.70 USD. In [Bill]’s own words, “Five bucks and some sweat equity gets you a device capable of worldwide communication.” He’s not kidding either. [Bill’s] first QSO was with a ham in the Azores Islands of Portugal.

[Bill] built his radio using the “Manhattan” building style, which we’ve seen before. Manhattan style uses rectangular pads glued down onto a copper ground plane. It makes for a more flexible design than regular old dead bug style building. Looking at all those components may be a bit daunting at first, but plenty of support is available. [Bill] has an 18 part build log on the soldersmoke website. There also is an active yahoo group dedicated to the BITX.

Comments

  1. pcf11 says:

    It has always amazed me how little interest I’ve had for radio when I’ve always been such a huge fan of electronics. The board does look like a nice homebrewed circuit though. Too bad it isn’t just an audio amplifier. I’d be more interested in that.

    • Joseph says:

      It is funny how interests seem to categorize themselves. I’m just the opposite. No interest in audio, some interest in robotics and home automation, but show me an rf schematic or wireless device and I’m drooling.

    • Larry R says:

      GEEEEEWHIZZZ !!!! Go build an audio amp and quit whining, you do not have to bring down the good spirits of everyone else that is looking for SDR or any radio for that matter…last time I checked, it was still America….go do your thing….

      L.Roberts

    • Jim Campbell says:

      I am with you on that. I for the most part do not maintain an active interest in RF, but LOVE audio amplification, especially guitar amps. I am currently working out the design aspects of a hybrid tube/solid-state amp where the pre-amps and power amps are completely user selectable (i.e. ss/tube, tube/ss, tube/tube, ss/ss). Esentially two complete amps in one.

  2. CoytHV says:

    Very nice little radio!

    I’ve been working on one as well http://coytbarringer.com/small-20m-ssb-transciever/ unfortunately i’ve had other projects take priority so I haven’t had time to get it working. I also just ended up buying a FT-817 that does everything.The Manhattan style is really a fun way to prototype though.

    I wish someone would come out with a design for a BITX or similar HF QRP SSB transceiver in a super small format utilizing all surface mount parts. I want an ultralight radio that I can take hiking to the top of a mountain that isn’t CW.

    • Bob says:

      There are SMD BITX kits out there. They look pretty small, too.

      • Me says:

        The only one I have seen was discontinued. Do you know of an SMD BITX kit that is available today? Even just a downloadable PCB design file to send to a board shop would be good too. I think I do remember seeing one of those but the author hadn’t built/tested it.

        • Bob says:

          Not sure of any on-going one but a full unbuilt kit is on eBay right now.

          • Me says:

            Really? How did you find it? I tried searching for both “BITX smd” and “BITX surface mount”. I came up with nothing. Searching for just BITX only got me all the usual non-surface mount kits.

            Oh well, I don’t have the cash for it today anyway, It’s time to start buying Christmas presents and I still don’t have transmit working correctly on my through-hole BITX. I’d still love to get ahold of a BITX surface mount PCB just so I can hold on to it for later though.

    • Deg says:

      Elecraft K3? Very small and light HF QRP SSB transceiver…

      • Deg says:
      • Rob says:

        the K3 isn’t a diy kit so much as an exercise in mounting preassembled boards and connecting leads. I understand that the level of miniaturization means that if they offered it as a true kit, the error rate from most users trying to solder smd’s and tweak/align coils would be the death of the kit, so I don’t blame them. But it just doesn’t speak to my inner Heathkit geek the way some other kits do.

        What Bill Meara did here is really impressive!

        • CoytHV says:

          Yeah, i’ve heard the KX3 is an awesome radio, but I’m talking about a small DIY radio that you just solder together or something maybe around $100 instead of $1000. If you could fit a one band 5W SSB transciever in an altoids tin and make it between $100 & $200 you’d have my money. This would not be a trivial task, but it could be done. Start with the BITX and just make it smaller.

          There are a few old HT’s on the market close to what I’m talking about. See Tokyo Hy-Power HT-750.

          @Bob I haven’t been able to find a good SMD BITX kit on the market now. Seems just a few websites with sketchy board files. Maybe we need to form some sort of community to build something like this?

          • Randy says:
          • CoytHV says:

            @Randy

            The RXTX Ensemble would be perfect and I’ve thought about using it before, but it is a full SDR. It needs a high quality USB sound card to act as an ADC / DAC as well as a computer to run it. I thought about using a tablet to run it, but code still has to be written and i’m not sure if the audio chip connected to the headphone/mic jack of current tablets have a high enough sample rate. External sound cards are still possible with a tablet & OTG port, but they are huge (as big as the RXTX itself).

          • Randy says:

            @CoytHV: You’re right, which is why I just splurged on a KX3 when they came out. It’s a pretty amazing rig, about the same size as the head unit on my mobile UHF/VHF rig in the Jeep. I do wish there were more standalone QRP kits that had SSB capabilities in the $100 price range.

    • Irish says:

      @CoytHV: Why don’t you take that BITX schematic, and rework it with SMD components, and build yourself one. You may not be able to replace every part with an SMD component, but I’m sure you could replace enough that you could end up with a fairly small package.

  3. where are the cheap kits ?
    I would like to build one from a kit ~ $50 would be fine but they appear to be nearly $180

  4. Very cool, I wonder how stable it is.

    I would like to build something like this for doing SOTA (Summits On The Air) activations. I have an FT-900 which is much too large to hike with and I don’t have the scratch for a portable HF rig. 20 meters is a good choice for SOTA as well.

  5. Miroslav says:

    I would like to get that variable capacitor for $4.70 somewhere … they are getting hard to find.

    • seaeg says:

      Make a 3D printed one!

      • vpoko says:

        WTF?

      • Greenaum says:

        I got an extremely cheapskated electronics kit as a kid, for Xmas. The kit itself wasn’t cheap to buy, but it was very cheaply made. Essentially a breadboard, it came as a moulded plastic case with holes, and you had to squeeze the metal clips in yourself! The same with a variable resistor, came with a track and separate copper contacts. Finally, the variable capacitor. 4 or 5 thin copper half-circles for the stators, and the same again for the rotors. Mounted onto a moulded plastic shaft with a knob on the end, and used a sheet of mylar pre-stamped with circular cutouts. So you had to assemble it yourself.

        In a way it was educational, mostly it was very, very cheap (in the worst way). And of course meant you couldn’t always follow the projects in the book, because your breadboard would have broken contacts, and you were lucky if you got the variable capacitor working at all.

        Throw in a bag of components and a badly-written manual, Ta-CRAP!

        It was manufactured on a Kibbutz in Israel, I seem to recall. Tree of Knowledge or something. Very strange.

    • Me says:

      The GQRP club sells them for 1.40 Brittish Pounds. http://www.gqrp.com/sales.htm

    • pcf11 says:

      I have it’s twin sitting in a pile of scrap behind my monitor. I think I picked it up with a load of rubbish at a flea market. Yup there it is:

      In the back right. Everything but the pliers, and the clamps came in the metal box for a dollar. I’m a sucker for analog meters what can I say?

    • static says:

      They can still be found new. Not for $4.70, but closer to $11. Sorry if $11 is too much you don’t want one very badly.

  6. radiobuilder says:

    Geez, some of you have the “appliance operator” attitude.
    You know, “just-go-out-and-buy-ready-made-radio”. Amateur
    Radio (“hams”) were the original “hackers”. Building radios
    from (as the article wrote) from nothing but scrap TV parts !

    I fondly remember those days of a “tube tester” being available
    at the local five and dime store.

    Nothing wrong with buying a ready made radio (heck I have
    an ICOM R9500 receiver and an ICOM IC7600 in my shack).
    But not everyone can afford expensive equipment. So this
    build using nothing but scrap parts is a good testimonial to
    the “hacker spirit” (in *my* opinion, that is).

    • pcf11 says:

      The original hackers had hatchets. Many of them were called bodgers by trade.

    • static says:

      As I understand the early radio experimenters built many of the actual components themselves. Not that many dead consumer electronics to salvage. Imagine building capacitor after capacitor until finding out worked at every place a capacitor was used in a circuit and doing likewise for inductors, and resistors. Reapeating this for every circuit variation that’s made

      • Irish says:

        We had to build a capacitor in my high school electronics class. slips of paper between stacked layers of lead foil, inserted into a jar with a brine (i think) solution…ahh, those were the days.

  7. Me says:

    The GQRP club sells them for 1.40 Brittish Pounds. http://www.gqrp.com/sales.htm

    • Rob says:

      For club members only…

      • Me says:

        I thought they sold to non-club members just at a slightly higher price? Either way it’s worth checking out. Membership isn’t that expensive and if you want to build small low-parts count radios the magazine is great.

        No, I’m not just plugging for them. I was actually going to recommend not just GQRP but Ebay and Dan’s small parts as well. I’m sure it’s been less than a year since I was shopping for them. I checked before posting though. Ebay didn’t have many and they were way more expensive than I remembered. Dan’s small parts didn’t have them at all. It would seem things have taken a turn for the worse in only a few months!

  8. Simon says:

    I’ve built most if of it out of parts I had laying about.I just got stuck at the main VFO and its been laying in a box for 10 months, partly due to not having a variable capacitor and partly due reading up on people building their own oscillators out of discrete components and about the great lengths they went to to get it absolutely stable. I’ve so far verified that the filters work, as does the BFO, but for now it only picking up noise at 10Mhz :P

  9. Joe says:

    http://www.qrpkits.com/ If you want a DIY kit for bitx

  10. Mike says:
  11. DarkerThanBlue says:

    ooooooooWOW! I’ve wanted to get into Ham Radio many times over the years, but couldn’t justify the equipment costs. That BITX tranceiver looks SWEET. Not too complicated to build, and super cheap, AND yet it’s a real superhet. I’ve done lots of HF prototyping, so this looks positively doable. It just may be time to jump in! Now I’m going to have to go look up the FCC requirements…

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