[hpsdr] Hermes

[FRANCIS CARCIA]

1. The low pass filter at the D/A output is between two transformers. I wonder if it would be better to build a blaanced filter with the  transformer center taps grounded. Maybe float the whole thing to avoid ground noise. no extra parts.
2. A/D How about the faster part?? Mount it on the bottom of the board with a lot more thremal plane. Yes it will run hot but I like air conditioning when I get hot.  MTBF??
When mounted on the bottom heat raises away from the die through the thermal interface.
3. 2 cascaded regulators going 12 to 5 volts. I wonder if the first one could be a resistor and zener to save area. 
 
Keep the LEDs, nice life monitor. Frank WA1GFZ
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/attachments/20090914/f4a20210/attachment-0004.htm>