[hpsdr] picoPSU Noise Test #2 - not just a pretty face?

[Christopher T. Day]

After the formal TeamSpeak session today, I got into a discussion of my
picoPSU noise test results with Larry (K2LT) and Duffy(?). The result
probably will be that I send one of the supplies to Larry for him to
test with his spectrum analyzer, etc.; he tests such things for
broadcasters professionally, but the 60W version only arrived Wednesday
and I want to savor it a bit longer. Meanwhile, he suggested an
alternative test.

 

I'm using a SoundBlaster MP3+ for my SDR-1000 sound card. This is only a
16-bit box, but it is USB and external to my laptop. Larry suggested
that I put it, as a better representative of Janus, near the picoPSU and
see what happens. So, I put my SDR-1000 back on 160m, terminated the
input coax with a 50ohm dummy load to remove sky noise and set the MP3+
on top of the picoPSU-60-WI. See photo at:

 

< 

http://www.hamsdr.com/personaldirectory.aspx?id=318

> 

 

The result is in the RTF (WordPad) file at:

 

< 

http://www.hamsdr.com/personaldirectory.aspx?id=319

> 

 

This time, I see no effect at all turning On the Feeder Supply and
picoPSU, albeit there is no load yet on the supply!

 

The MP3+ is a quite inexpensive box. From its weight, I would say its
case is strictly plastic; once I get the nerve to void the warranty and
open it up, I will check for internal shielding, but I'm betting it's
minimal at best.

 

Whew, that makes me feel a little better, at least until morning.
Comments?

 

 

            Chris - AE6VK

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/attachments/20060609/20887572/attachment-0003.htm>