[hpsdr] New Hermes 2M Board

[Helmut Oeller]

Hi Larry,

We can gladly continue our discussion in detail also off list. I hope that I
waste not too much bandwidth here for the following conclusion:

1. There exists no practical and economic alternative to the 14/16 Bit, 140
Msps ADC with ENOB > 11.5. But that's more we need, if we use intelligent
methods in our real-time application to keep the ADC at its best DR of 95
-100 dB, i.e. advanced software control of preamp or S-ATT depending on the
environment conditions. Each Smartphone can keep connection to the base
despite another phone operates close by and both employ an analogue direct
conversion frontend (hi).

2. As the impact of manmade noise and RFI becomes a more severe problem than
intermodulation, caused by broadcastings stations in the past, it's very
helpful to provide two ADC channels for diversity etc. If not used the
second channel can provide undersampling of VHF-bands. Even crossband
operation is possible.

3. Military applications like frequency hopping, spread-spectrum modulation,
MIMO etc. are not of interest for the majority of the hams. Even very
interesting options like FreeDV waste away. Last but not least all has to
fit into a reasonable economic frame.

73, Helmut, DC6NY