[hpsdr] Call for Comments and Discussion - CYCLOPS

[Henry Vredegoor]

Hi Phil, Graham, All,

Regarding your RFC on the design for Cyclops, I have a few remarks /
questions:

A. Why was the second IF frequency of 96 MHz chosen? 
   As far as I understand there should be no particular reason to choose
this particular frequency as IF?
   I ask this because I fear that at this IF of 96 MHz the chance of picking
up or leaking trough 
   unwanted transmissions from the FM broadcast band might be an issue?
   The frequency of 96 MHz is smack in the middle of our FM broadcast band
here in Europe!

B. If you use 96 MHZ I understand that Mercury will have to be modified to
be able to use this frequency.
   It would be nice to include a short description on the Cyclops Wiki of
how this would be done hardware 
   and software wise and (if there are) any consequences for normal Mercury
operation.

C. There seems to be no termination/buffering of the 10 MHz reference from
the Atlas bus to the card.
   Of course keeping down the component count is a good thing, but as there
are hanging more and more cards
   on the Atlas 10 MHz reference bus signal line, wouldn't a bit of
termination/buffering be better/required?

D. Not a phase locked, local 10 MHz reference, locked to the 10 MHz
reference Atlas bus signal like on Mercury?

E. Maybe a targeted (preliminary-) mini spec would be nice to be included in
the Wiki.



These are just the remarks from an armchair developer, so please bare with
me.....

Thanks for all your very good work!


Regards,

Henry.


> -----Original Message-----
> From: hpsdr-bounces at lists.openhpsdr.org 
> [mailto:hpsdr-bounces at lists.openhpsdr.org] On Behalf Of Graham / KE9H
> Sent: zaterdag 11 juli 2009 23:55
> To: hpsdr; Phil Harman
> Subject: [hpsdr] Call for Comments and Discussion - CYCLOPS
> 
> 
> ***** High Performance Software Defined Radio Discussion List *****
> 
> All:
> 
> An information package has been posted to the Wiki on the
> CYCLOPS page, under the "July 11 Update" heading, with
> block diagram, schematics and a proposed PCB layout for
> a prototype CYCLOPS spectrum analyzer card.
> 
> The Tracking generator will likely be a separate card developed
> after the main SA receiver card is running.
> 
> Please review the package and direct questions, comments,
> constructive criticism, etc to Phil, VK6APH or myself. Phil is the
> project leader and designer.  I have been assisting Phil with
> the PCB layout, bill of materials and sourcing.
> 
> --- Graham / KE9H
> 
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