[hpsdr] Atlas Firs Light

[Eric Ellison]

Chris

 

Thanks for the prompt testing!

 

Probably also appropriate that it is Atlas who holds up the heavens from the
earth and sees first light.

 

In spite of the fact that you say it is jumpered does it cold switch
properly?

 

Hmmm.. No -5 volts? That is really not a problem at all since we have -12
volts, however, since the Pico and as other observers have noted that ATX
supplies are doing away with 5 volts we should consider dropping the -5
volts from the design. Since a designer can not count that it would be there
in all PS setups it would be unwise for him to ever use it as a source. With
that in mind, some parts, real estate, and re-use of the -5 volt plane area
would be in order.

 

Comments:

 

Eric - AA4SW

 

 

 

 

  _____  

From: hpsdr-bounces at hpsdr.org [mailto:hpsdr-bounces at hpsdr.org] On Behalf Of
Christopher T. Day
Sent: Sunday, April 23, 2006 2:08 AM
To: hpsdr at hpsdr.org
Subject: [hpsdr] Atlas Firs Light

 

Bulletin:

 

 

I have posted a picture - only 600x800 this time - of "First Light" observed
with the Atlas board.

 

http://www.hamsdr.com/personaldirectory.aspx?id=196

 

I got anxious to see something, so this is an early stage. The tantalum
capacitors are not installed because of the size issue I mentioned in
earlier e-mails. The ceramic bypass capacitors are all installed as well as
the dropping resistors and LEDs. I will do the DIN connectors next. There is
a jumper in the Power_On# position; no switch on hand. That's all that's
needed for this board.

 

My picoPSU-120 is plugged directly into the ATX power connector. There is
_no_ extra load resistor on the board. If you look carefully, you will
notice that only four of the five LEDs are lit on the Atlas board. (The
picoPSU has a red LED and a grenn LED of its own; green for power applied
and red for power on, apparently.) This, as it turns out, is not wrong - the
picoPSU only supplies -12V, not -5V and that's the LED that is not lit.
Voltages at J20 look fine.

 

Looking good! More pix to follow.

 

 

            Chris - AE6VK

 

P.S. - "First Light" is the term for the inaugural picture from a new
telescope.

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