[hpsdr] [ATLAS] Alpha bare board pictures posted - April 6, 2006

[Philip Covington]

On 4/6/06, vk4str <vk4str at netspace.net.au> wrote:
> Hi Phil and group,
>
> The photos of Atlas are looking really good, congrats Phil!
>
> Makes me feel like wanting to heat up the soldering iron, hi! No doubt
> you will be doing that right now.
>
> I do have one comment regarding the Atlas concerning the bypass
> capacitors near the ATX PS connector. Due to the length and width of the
> connecting tracks from the ATX pads the bypass C's wont be very
> effective. IMHO it would be better and more effective if they were moved
> as close as possible to the ATX pads with the shortest possible track
> length and maximum track width.
>
> Alternatively another solution would be to have a GND area sourrounding
> the ATX connector on the bottom layer with enough Vias to the top GND
> for low impedance, and to position the bypass C's on the bottom layer
> very close to the actual ATX connector pads.
>
> Or a mixture of the above, bypass C's mounted on top and bottom to
> maximize effectiveness by minimizing connecting track lengths.
>
> I had a look at the FPGA-USB board schematic, WOW!! Phil you really have
> got the Adrenalin flowing! This is an absolutely outstanding effort
> Phil. I need to have a look at the block diagram if I can find it, to
> better understand the connectivity within system components. This is
> exactly what I have been thinking of for a long time.
>
> Thanks for the great efforts.
>
> 73, Helmut VK4STR

Hi Helmut,

There is certainly nothing to stop people from adding some more bypass
caps on the underside of the board if they find that they need them. 
The ground pins on the ATX connector are close enough and distibuted
enough to allow the placement of some 0805 ceramics right at the power
pins.

73 de Phil N8VB

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