Join the Conversation

11 Comments

  1. It’s got a 2.3GHz to 2.7GHz front end, and a 20Megabit ADC/DAC, so how does it cover 30MHz to 2.3GHz and 2.7GHz to 6GHz?

    1. Maybe it gets the claimed coverage through an on-board mixer? As there is no block diagram and/or theory of operation for this design (that I can find), it seems inspecting (reverse engineering) the schematic is the only way to figure out what’s going on. Find the schematic etc. here:

      https://github.com/mossmann/hackrf/wiki

      Also, the developer claims:

      “The maximum bandwidth of HackRF is 20 MHz, about 10 times the bandwidth of TV tuner dongles popular for SDR.”

      This is certainly a feature – but how does this happen? USB 2.0 High-Speed is effectively around 280 M-bits/s, but in reality significantly less in my experience as the throughput is application (the SDR software you’ll use) limited. Consider you have two data streams in-phase (I) and quadrature (Q) over one USB port. That halves the raw throughput.

      The about 10 times BW claim over TV tuner dongles is in my opinion a bit high. With careful settings, I can get around 2.5MHz span with a RTL-SDR dongle. 3MHz is pushing it.

      Nice to see this SDR product make it to market. At my writing time the Kickstarter threshold has been met.

      1. Thank you tayken for the link to the ToorCon slides. I have them already. Unfortunately these slides are in my opinion far less than adequate to explain what’s going on with the HackRF design. That’s why I did not reference them in my post. To other readers, if you download the ToorCon slides referenced by tayken, be prepared to see something hand-written on a pocket paper notebook with reference to the likes of “High-IF”, “Double-Conversion” etc. with no demarcation as what is being done in this respect in the analog vs. digital signal-chain. So AFAIK it is back to reverse-engineering the schematics, which at post time I have not had time to do. But I will have a crack at it eventually.. Someone (the Developers maybe?) should document this project (now product) properly before asking for hundreds of Dollars to purchase – I’m not seeing this level of documentation as of post time.

    2. Right so looking through the schematics, the 2.3GHz to 2.7GHz signal is then run through a 30-6000MHz mixer to up/down convert it for the stated bandwidth.

  2. I got the email and had to go for the $310 option (a crazy bargain IMHO). I was too slow for the ‘early bird’.
    I have had a lot of fun with my beta unit. I can’t wait to get another.
    This is an awesome piece of hardware!

  3. When I looked at the mail about 50% of the early bird boards where still available. But I though that this $200 board will probably just end up in a drawer just like my RPi (from the first 10000 batch they did, so maybe it will have a collectors value some day ^_^ ) so I let someone else get my “slot”.

    I rather save up for a OpenBTS station from Range Networks http://www.rangenetworks.com/store/development-kit instead. Then I’m forces to use it since I’ve spent so much. :-)

    1. Hi Mats, Five Grand for that OpenBTS box? Wow. I don’t think so. Doesn’t the Ettus SDR box do OpenBTS? BTW, don’t let that RPi sleep in your drawer. It is a great device to bang on. There are so many projects to try because of broad community support. Turn it into an Web enabled environmental monitor, IP camera, Sous Vide PID controller, media player, whatever… Google almost any project you want and ad “RPi” to the search and you’ll probably come up with at least one hit with instructions. The only thing bad about the RPi is the slow GPIO, but all the ARM-like devices out there have the same issue due to on-chip busses (like AMBA) and no open drivers for DMA work-arounds – not just the RPi. Sorry, I’m getting off-topic. But I hate to see a RPi go to waste ;-)

  4. Hi Michael

    I am interested by your realisation
    Could you send me a data sheet / flyer and a technical description of your product.

    Many thanks

    Philippe

Leave a comment

Your email address will not be published. Required fields are marked *

Notify me of followup comments via e-mail. You can also subscribe without commenting.