Q. What is the frequency range?
A. 64-1,700MHz, although straw poll tests on pre-production units indicate that units can be stretched down to 51.5MHz or so. Upper frequency limit is beyond 2,000MHz. In testing, we have determined that there is a gap between about 1,100MHz and 1,270MHz where the design of the local oscillator VCO, PLL and divider chain in the tuner chip don’t provide seemless coverage.
Q. What can the FUNcube Dongle receive?
A. The FUNcube Dongle has no restriction on modulation schemes: it is limited only by the application program running on the host computer. As long as the signal fits within about an 80kHz bandwidth, the FUNcube Dongle is capable of receiving the radio signal. So, for analogue reception, as well as narrow band FM and SSB, it is also possible to receive, for example, sound subcarriers for TV broadcast. Similarly for data reception, as long as a data demodulator has been written that will accept standard soundcard quadrature I/Q reception, that will work too.
Q. What is the bandwidth?
A. 96kHz is the quadrature sampling rate. Once the ADC’s decimation filter skirts have been taken into account, you have about 80kHz.
Q. What applications work with the FUNcube Dongle?
A. As well as the forthcoming FUNcube front end application, any application that understands a standard stereo soundcard configured for quadrature, or I/Q, reception should work. Examples include Linrad, Spectravue, Rocky and M0KGK.
Q. What is the sensitivity?
A. Each unit is tested for 0.15uV for 12dB SINAD NBFM at 145MHz and 435MHz.
Q. What operating systems are compatible?
A. Currently Windows 2000 SP4, XP 32 bit, and Vista and Windows 7 32 and 64 bit have been tested. The sound card element works with Mac OSX and Ubuntu 10.10 32 and 64 bit, but the frequency setting application has not been ported yet.
Q. What’s the difference between versions?
A. There are two versions, the Base and the Pro models. The Base model is frequency restricted and designed as an entry level minimal cost device, targetted for educational outreach. The Pro model is unrestricted in its frequency coverage.
Q. Can I upgrade a “Base” version to a “Pro” version?
A. At present, the upgrade will require a return of the device so that it can be modified to accept “Pro” firmware.
Q. Is the firmware upgradeable?
A. Yes, already the devices can have their firmware upgraded in a matter of a few seconds by the user. However, Pro firmware and Base firmware are not interchangeable.
Q. Do I need front end filters?
A. Some people have experienced front end overloading with the FCD at VHF in particular. Although there is fixed and programmable front end filtering already on the FCD, at VHF it’s not very selective. Typically the symptom is that it will appear deaf: this is the noise floor rising due to an overloaded front end. You can see this in Spectravue as when you plug in the antenna the noise floor rises potentially several tens of dB. Although reducing gain can help, of course innevitably this is at the expense of the unit’s native sensitivity. At this stage it is worth pursuing external filtering options. We’re working on some solutions already, but some readily available commercial solutions include Hamtronics’ LNP preselector, SSB Electronics SP-2000, and DCI’s DCI-145-2H and DCI-145-4H. As these are not exactly cheap, I have been working on some ideas here that you may like to try: http://www.funcubedongle.com/?p=456. We’re also investigating at a reasonably priced active no-tune solution.
Q. I am having trouble upgrading the firmware. What can I do?
A. The most reliable way to do this is from Windows. It is essential that, after placing the unit in bootloader mode, any other software that might access the FCD is shut down before you attempt to update the firmware.
Q. What support options are there?
A. You can email me using my Paypal email account, or alternatively there is a very active FUNcube Yahoo group that often provides answers more quickly! http://uk.groups.yahoo.com/group/funcube/