[hpsdr] picoPSU Noise Test #2a - Looking good!

[Christopher T. Day]

I've done several things for this test.

1) I've opened the MP3+ box and verified that it has no internal
shielding at all.

2) I've put a 2ohm load on the 5V rail to give the PSU something to do.

3) I've followed Ahti's suggestions:

	a) Preamp at "High" [I wouldn't have thought that would matter
much for audio card pickup, but can't hurt, I guess.]
	b) Moved the MP3+ as far away from all power supplies as cable
lengths would allow for the reference measurement.
	c) Placed the open MP3+ on top of the loaded picoPSU for the
noise measurement.


A picture of the noise measurement set up is at:
<
http://www.hamsdr.com/personaldirectory.aspx?id=325
>

The results are in the RTF (WordPad) file at:
<
http://www.hamsdr.com/personaldirectory.aspx?id=327
>

This is looking _much_ more promising, at least until someone tells me
how I'm fooling myself. I don't see any change at all.


	Chris - AE6VK


-----Original Message-----
From: Ahti Aintila [mailto:oh2rz.sdr at gmail.com] 
Sent: Saturday, June 10, 2006 2:20 AM
To: Christopher T. Day
Cc: hpsdr at hpsdr.org
Subject: Re: [hpsdr] picoPSU Noise Test #2 - not just a pretty face?

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