[amsat-bb] Fwd: [funcube] Don't forget the FUNcube dongle is on sale today!

Mark L. Hammond marklhammond at gmail.com
Thu May 26 11:11:15 PDT 2011


FYI!

73,

Mark N8MH

---------- Forwarded message ----------
From: m0tfo <robpegs at hotmail.com>
Date: Thu, May 26, 2011 at 2:05 PM
Subject: [funcube] Don't forget the FUNcube dongle is on sale today!
To: funcube at yahoogroups.co.uk




The FUNcube dongle Pro will be on sale this evening (21:00UTC.)
The sale times are now lasting longer,so this is the best time to grab
yourself an SDR dongle.
Order here:http://www.funcubedongle.com/?page_id=286

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.

Rob M0TFO


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