[DSP-10] new builder

[Bob Larkin]

Hi Andy,

Thanks for the note to the reflector. I'll try to answer your question, and
also add a couple of words for the non-RSGBers! Peter Rhodes' project is
indeed (almost) compatible with the DSP-10. He has some other circuitry for
the AGC of the PIC-a-STAR, but that can be ignored.

He also has the initialization code for the AD1885. This is where the
"almost" comes in. The DSP-10 uses the AD1847 (no longer available without
buying the EZ-Kit).  What I would be happy to do is to fix up a version
using the 1885, as the only part that is different is the initialization.
Peter has fixed that part up and kindly made it available to us. At this
time, I do not have an 1885 available for test, but the change is
straightforward enough that we could do the testing remotely, I think. Peter
has deliberately attempted to keep the hardware DSP-10 usable.

For those that are not familiar with Peter's project, it is an SSB/CW HF
transceiver using a PIC front panel. The IF has quite a lot in common with
the DSP-10. Peter has omitted some of the weak signal and spectral analysis
stuff, but has added noise blanking and better AGC, amongst other items.
Software can be downloaded to the PIC/DSP from a PC for alterations, so it
is a true SDR (software defined radio).

They are hand making the DSP (and other) boards, and I believe the current
issue of RadCom has the details of the DSP.  The board patterns
(double-sided) are available, they use the Xerox/Iron-on process to transfer
the pattern and then you etch it away. The need for through vias is
consistent with the process, by Peter's cleverness.  Soldering is by way of
AA7QU/G3XJP "Weld-and-Wick" method, where you blob on all the solder
possibly needed, and then wick off the extra (yes, it really does work!).
Andy, maybe you want to add to these comments, if I have errors.

One other comment, there remains a possibility that a more conventional
EZ-KIT substitute will be available. This is not certain, and I can't say
more now.  If anyone is interested in pursuing the PIC-A-Star approach, jump
right in and don't wait for alternatives.

If anyone has access to RadCom for the last 6-monhts, or so, take a look at
the STAR project.  Also, look at the CDG-2000 project. Two nice (big) projects.

Anyone else have comments on this??

73,
Bob Larkin,  W7PUA

At 12:02 AM 2/6/03 +0000, you wrote:
>
>I've been contemplating a build of the DSP-10 for some time, the main 
>barrier being the high cost of the AD EZ-Kit Lite - $260 last time I 
>looked.  A viable alternative looks like Peter Rhodes' (g3xjp) 
>PIC-A-STAR published in RadCom (RSGB magazine).  Has anyone else 
>considered this approach or are there other replacements for the AD demo 
>board?
>
>Regards
>--
>    Andy Rutter
>    g8hck
>
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