[hpsdr] Mercury info

[Bill Tracey]

Don't know on 1.  On 2 -- 122.88 MHz is correct - this is the 
frequency of the master oscillator on Penny and Mercury.  It is used 
to drive the D/A and A/D converters.  It is also divided down to 
12.288 to drive the audio codecs.    We'd originally gone with 125 
MHz as the master oscillator freq but the lack of an integral divisor 
down to typical audio sampling rates (48, 96 and 192 khz) proved 
problematic to the software so we switched to 122.88 MHz which 
divides down nicely to the common audio sampling rates.

Regards,

Bill (kd5tfd)

At 03:55 PM 12/30/2008, Alberto I2PHD wrote:
>***** High Performance Software Defined Radio Discussion List *****
>
>Just a couple of dumb questions, still waiting for my Mercury to 
>show at the front door...
>
>1) What are the differences between the Mercury proper, and 
>Mercury-EU ? Do they use the same firmware ?
>    Are there significant functional differences ?
>
>2) I continue to read, both in the jumper settings message and in 
>another message, references to
>    a 122.88 MHz clock. Is this number correct, or should it be 12.288 MHz ?
>
>Thanks
>
>73  Alberto  I2PHD



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