[hpsdr] single board rigs *YES* please...

[Alex, VE3NEA]

Hello,

> I can understand both sides of the argument.  Currently the plug in
> board model is great for experimenters.  The building blocks allow you
> to assemble a system in different configurations without committing
> completely to a final design like you would end up with if the same
> modules were condensed down to a single board.

This is true, but only in theory. What options do the owners of the
Atlas/Ozy/Janus boards currently have?
Can they replace one of these three boards with something else? I guess no,
unless they design their own
board.

The development of a new board for HPSDR is not an option for most of us.
This requires

1) very good hardware design skills that most hams do not have, even though
many are willing to learn;
2) a significant investment in the components: prototyping is much more
expensive, in terms of parts, than
kit building;
3) lab equipment: an oscilloscope, a signal generator, etc., etc.

So far, only a handful of hams were able to solve these problems and
contribute hardware to the HPSDR project.


Software is very different in this respect. The freeware development tools
are available on the Internet, as well as all kinds of programming
tutorials. If one had a working hardware, all one would need to start
programming is the desire to learn. A minimum cost, single board unit would
allow many of us start working on the software - even though such design is
not very flexible from the hardware experimenters' point of view.


> I think some will be surprised at the cost of the Mercury board.  The
> single most expensive component on the Mercury will be the LTC2208 at
> ~$90.  The Cyclone III FPGA is about $40 and the configuration device
> for the Cyclone III will be around $15.   Being on the cutting end is
> not cheap!

This is not cheap, but still affordable for many of us - until we add Atlas
and Ozy to the picture, and the price doubles.

For me, Mercury is by far the most exciting unit in the HPSDR family. While
Janus improves the quality of the existing solutions, Mercury opens the door
to a completely new technology, with unlimited possibilities of
experimentation with software. Also, the Atlas/Ozy/Janus combo still
requires an external receiver with I/Q output while Mercury can be built as
a functionally complete receiver, QuickSilver - style.

I vote for a single-board Mercury. Since its PCB design has not started yet,
it may be possible to add an USB interface to the unit and turn it into a
"direct RF sampling receiver for masses". Not only such receiver will allow
experimentation with software on a large scale, but it will also have many
practical applications. It could be used as

1) the main receiver of the base HF station, with a conventional transceiver
used for transmission (frequencies synchronized in the software);

2) a beacon moniroring receiver that slices all 5 freqencies of the NCDXF
beacons simultaneously (about 1 kHz around each frequency would be required,
so monitoring could be done in the background with most of the bandwidth
still available in the normal receiver mode);

3) DX monitoring: 20 KHz or so from the total 192 KHz bandwidth would be
sliced on each band - e.g., the CW DX window, or the digital segment of each
band. Imagine a program that copies all RTTY signals on all bands, and works
as an automatic DX cluster - with spots generated from the copied signals.

These are just a few examples, the possibilities that a single-board Mercury
would open are unlimited.

73 Alex VE3NEA






 1191430606.0