[hpsdr] HERMES schedule question

[Kjell Karlsen]

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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