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Is there a
production version ?
NB: All we need now
is a HDL module .. Huey Dewey and
Louie
Sent: Sunday, November 21, 2010 11:25 PM
Subject: Re: LF: ROS Latest with I/Q output
On 11/21/2010 2:41 PM, Andy Talbot wrote:
There are plenty of receiver packages for Softrock. clones
and similar - now how about more SDR transmitter
software. Giuliano I0CG and myself presented a working prototype
of such a project at the Castelfeder (near Bozen, North-East Italy)
meeting,
last October. The PDF of my presentation is here :
http://www.i0cg.com/presentazione_i2phd.pdf
Unfortunately it is in Italian, but with some fantasy and guesswork
maybe it can be understood.
Giuliano is the author of the hardware project,
while I wrote the DSP software for the dsPIC.
Synthetically, the audio
signal coming from the microphone is digitized by the on-board ADC converter of
a dsPIC chip at a sampling
rate of 15501 Hz, then upsampled to 248,016 Hz,
then sent through an SPI interface to an AD-9957 device, which is dynamically
programmed
to provide an SSB output that can range continuously from about
zero up to more than 100 MHz (the final sampling frequency is 250
MHz).
It was tested on the air in SSB QSOs with the US on the 20m band,
and received unsolicited comments about the very good quality
of the
modulation.
Some more info on the page of Giuliano : http://www.i0cg.com/ad9957_dds.htm
73
Alberto I2PHD
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