[hpsdr] HERMES schedule question

[Ray Page]

Hi Kjell,

Thank you very much for your update. I am interested in rolling a version of
HERMES as well. I'm very excited about this design. How might I obtain the
latest schematic? Orcad would be great if that's what you used. If not, a
PDF and BOM would suffice just fine. I'm hoping to be able to contribute to
the fine work you are doing.

I have a few more questions if you have the time to answer them...

1) What level are the RX spurs?
2) Have you discovered a correlation to any specific on-board source?
3) Am I correct about the following?
    a) The USB MCU is functioning as planned.
    b) Able to program the FPGA through the USB MCU.
    c) FPGA DSP path is working (or nearly complete).
    d) Signal integrity issues appear to be the final hurdle.

Thank you,

Ray Page



On Thu, Jun 17, 2010 at 4:03 PM, Kjell Karlsen <la2ni at online.no> wrote:

> ***** High Performance Software Defined Radio Discussion List *****
>
> Hi all.
>
> As I am the only one that has built a Hermes Beta board (as far as I know)
> I can give the present status:
>
> I finished the first Beta board 2 weeks before the Hamvention and the RX
> part worked  but with some more spurs that Phil likes. We decided to send
> this board to  Dayton installed in the Hammond enclosure also containing an
> Apollo board to show the mecanical construction.
>
> I got it bach a few days after Dayton and we continued the testing. Phil
> managed to get the software for the TX working so at the moment I have one
> working Hermes transceiver. There are still too much spurs in the RX but
> also some leacage of the different oscillators at the output of the TX.
> These problems seems to be related to grounding and decoupling of the
> different circuits. I have managed to get it much better than it was at the
> beginning.
>
> Tony is working on an updated schematic and the layout of the Gamma board.
> This will include one continuous groundplane and more decoupling capacitors.
> It will also include a Switch Mode 5V PSU constructed by me using one of the
> latest Switchers from Linear Tech. with a switching frequency near 2 MHz. I
> am not able to find any spurs from this SMPSU in the RX.
>
> To speed the process there will be made only one Gamma board. As I have
> time for it, I am going to build this one and test it in cooperation with
> Phil. Hopefully I can receive this board in the end of July. If all goes
> well I may have it tested after one week and then we can take a decision for
> further Gamma boards production.
>
> I hope this answers most of the questions.
>
> 73, Kjell
>
>
>
>
>
>
>
> På Thu, 17 Jun 2010 21:36:58 +0200, skrev Dan Babcock <n4xwe at yahoo.com>:
>
>
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