[hpsdr] atlas board

[Jason Hitesman]

Just learned about the -5 being optional myself this past weekend.  First I
made a mistake and somehow missed that the two negative LED's are mounted
opposite than the positives...don't know how I missed that.  But it was easy
to fix.

Then the second time I powered up my ATLAS I only got the +12 and the -12 to
light...uh oh. Flipped it over and the problem was obvious.  A small piece
of solder wick managed to sneak under the board while I was remounting the
negative LED's and was shorting out the +5 and +3.3 busses.  Crud.

Thankfully removing the offending piece of solder wick solved the problem
with no apparent permanant damage to the board or my supply.  But that -5
still wasn't lighting.

The easy solution at this point would have been to look at the label on the
power supply...I would have noticed that no -5 specs were listed.  But
assuming -5 was a required output I instead dug out the meter and checked
the connections at the ATX socket...which was when I noticed the pin for -5
didn't have a wire going to it and finally thought to read the label on my
power supply!

Oh well, it was just a spare supply I didn't plan on using for the radio
anyway (this thing came out of such a cheap computer I doubt it's anywhere
near quiet enough to use in a radio.)  Besides the -12 rail on this
particular supply was not very stable at all.  The three positive voltages
were rock steady (or at least more accurate than my meter!) but the -12 was
wandering between -9.5 and -11.5 not staying stable at all.  Not sure how
important a stable -12 is for this project...but given the overall quality
of the supply I had on hand and it's lack of -5 I'm going to keep looking
for a nice ATX supply ;)

-----
Jason Hitesman
N8INJ
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/attachments/20060725/da2c7a46/attachment-0004.htm>