Frequency coverage update


On Saturday I worked on some further testing including the frequency coverage of the device. At the bottom end, we seem to be able to consistently achieve coverage down to 52MHz and up to beyond 2,000MHz.

The spec sheet of the tuner chip states “64 to 1,700MHz” however we have found a gap between 1,100MHz and 1,270MHz where the local oscillator won’t lock. I’m currently characterising this across preproduction devices to determine a guaranteed coverage. We may be able to improve things by altering the fractional-N and post divider settings, but I suspect that this is a flaw in the tuner chip’s specification.


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6 Responses to Frequency coverage update

  1. Chris says:

    Hi Howard,

    Quick question on the dongle freq.’s, is it possible to get an oscillator lock between 1268.880 to 1268.850 MHz on the professional and educational versions Howard?

    I was going to ask you which was the three main chips you have used on the dongle circuit board and if I could obtain a datasheet for the actual chips. Reason I ask Howard is KiwiSAT is planned to use the above 23 cm band and I would like not only to use my modified Kenwood TS-790E but also use your dongle to listen on the frequency as portable and run a band scope too. KiwiSAT is carrying Science projects too. Any thoughts Howard?

    Also would it possible to build a 0.1 Hz to say 2 GHz receiver and band scope using the same SMD technology you have used Howard? Noticed a few commerical receivers and detectors going up to 6 GHz now’er days, shame we cannot get one to cover all of AMSAT-DL P5 frequencies too.

    Take care Howard and thanks for the best satellite ground station project I have seen in a very long time (more than 10 years), you have created a new emphasis in our hobby and possibly in the commercial world too.

    PS Did you read the ESA – My Gound Station response to my email?

    Chris, GW6KZZ

    • admin says:

      Hello Chris

      Thanks for your note. I haven’t spent much more time investigating the gap since I posted, in fact the firmware has been stable for quite some weeks now, which is good – in fact it has proven to be solid as a rock! I will however be opening it up again in the next week or so to add a few minor extra functions, and to see if the the gap can be closed at all.

      The devices I have used are a PIC24FJ32GB002, a TLV320AIC3104 and an E4000. As I think I have mentioned elsewhere the E4000 is subject to an NDA, as with most tuner devices in the set top box and TV dongle markets.

      I think if there is a follow on device it would be for a higher end device with extra functionality, with possibilities such as wider baseband, larger frequency coverage and transmit coverage. One of the beauties of the FCD seems to be its form factor. Trying to place any more than three large (ahem!) devices in a USB dongle would be challenging.

      The last email I had from you was on 18 October? Let me know if there was another.

      Again, thanks for your note.


      • Chris says:

        Thanks Howard, all noted and stored. You should have got two emails direct to your mailbox on 19/11/2010 re mygroundstation and Genso, if you have a different email address or didn’t receive them both just drop me a email on the link above.

        On the E4000, very impressed, just read the data and two articles, you have most certainly taken it a dozen steps further and would be nice if they generate a newer version chip with more bandwidth and without NDA block for mobile frequencies as everything these days is digital and decoding is restricted in America under ITAR. Bet you cannot get a GPS chip on a dongle too, lol.

        Thanks again Howard, everyone is so impressed with your work and the hobby springs to life again, getting your dongle to work with ESA GENSO will get everyone around the world after your dongle and make a global cube sat receiving network helping ESA and AMSAT too.

        Thanks again Howard,

  2. Ricky says:

    I’m looking for informations about the frequency coverage, is it 64.00mhz to 1700.00 mhz?
    Can I use the funcube dongle to receive and decode apt(137mhz)and hrpt (1698mhz) images from noaa satellites?

  3. Rob says:

    Hi Ricky, The spec can be found here, it will receive Noaa sats, but you will need software to decode.

  4. Ricky says:

    Thanks Rob