[hpsdr] Hermes Peer Review

[L. Van Warren]

This is a great effort.

General Comments:
1.	Build in rigorous diagnostic and self-test. LED's alone are not
sufficient.
		Untold hours are wasted from difficult to find bugs.
2.	Inputs and outputs from all sections should have ability to
self-test.
3.	I can write a platform-independent display program to show self-test
results.
4.	Add temperature, voltage and current sensing to critical fan-in and
fan-out points.
5.	Socket and fuse vulnerable components.
6.	Eliminate JTAG interface.
7.	Consider Gigabit Ethernet instead of USB2 to enable QS1R/USRP2
server architecture.

Specific Comments:
1.	Add internal GPS disciplined oscillator.
2.	The Linear LTC2208 ADC is a great part. It is extremely layout
sensitive. Contact David Dinsmore Field Applications Engineer for Linear
Technologies (referred by Van Warren). 2208 creates self-interference and
uses a special error correcting code strategy to get around this. It
requires six layer board with ground planes on top and bottom.
3.	Add complementary stereo line in, for symmetry with line out.
4.	Be generous in thermal analysis. Instrument hot spots accordingly.

Van / AE5CC / wdv.com