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

[Eric Ellison]

Guys

Going back a while.. Has anyone done any of these tests. This is a GREAT
little power supply for HPSDR Atlas. I'd hate to see it scrapped if it can
be salvaged. Even if we have to enclose it in a metal box it would be worth
it from the standpoint of making these projects into a portable design, and
a very small enclosure, which I think someone is working on. 

Can anyone do the qualifying tests? Can I throw some Bux at it to buy the
board for those wishing to test? If this will work a 'group buy' through
TAPR would save about 15 bux....

This thing is just too cute to abandon!

Thanks
Eric


-----Original Message-----
From: hpsdr-bounces at hpsdr.org [mailto:hpsdr-bounces at hpsdr.org] On Behalf Of
Ahti Aintila
Sent: Saturday, June 10, 2006 5:20 AM
To: Christopher T. Day
Cc: hpsdr at hpsdr.org
Subject: Re: [hpsdr] picoPSU Noise Test #2 - not just a pretty face?

***** High Performance Software Defined Radio Discussion List *****

Chris,

Could you still do the following test:
1. Use Preamp gain "High" instead of "Low" and antenna connector
terminated 50 ohm.
2. Place Sound Blaster MP3+ far away from picoPSU and any power cables
and check the noise level.
3. Move SB MP3+ on top of picoPSU.
4. Any difference in noise levels?

73, Ahti OH2RZ


On 10/06/06, Christopher T. Day <CTDay at lbl.gov> wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
>
>
>
>
>
> 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?
>
>
>
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>             Chris - AE6VK
>
>
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