The FUNcube Dongle As part of AMSAT-UK’s FUNcube satellite project, the FUNcube Dongle is the “ground segment”, or a radio receiver designed to allow anyone to try their hand at reception of satellites like FUNcube anywhere on Earth as part of a global educational collaboration project collecting information from space.
For more information on the FUNcube Dongle visit HERE
Order here:http://www.funcubedongle.com/?page_id=286
The FUNcube and FUNcube dongle user group can be found here
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.
© 2011 AMSAT-UK
