Topband: Noise in the Shack - A new noise!

[W2RU - Bud Hippisley]

Greg —

Your aluminum foil fix possibly eliminates direct radiation (from the SSD) as the noise source, but says nothing about conducted noise from the power cord (or other cables going in and out) of the desktop system.

If SSDs impose totally different current (pulse) requirements on the desktop's power supply, it's entirely possible you'd have a different RFI scenario on the power cord if it has inadequate filtering to begin with.  Putting cores on the SATA cable only affects common-mode currents ON THAT CABLE — it does nothing for common-mode currents exiting the desktop via other cables.  The SSD-specific power supply currents are differential mode between the power supply and the SSD itself, but can cause common-mode RFI emissions if the power supply does not have adequate filtering at the power cord's point of entry or to other cables in/out of the desktop chassis.

Also, you might want to look at whether SSD maximum current pulses are too much for your desktop's PS to handle, thus causing the PS to go into an abnormal state at some fairly repetitive switching rate.  That's assuming your SSD is powered from your desktop's internal PS.

If the SSD is an outboard unit with its own power supply, shielding the SSD itself will be useless if there's a power cable running between the SSD and a wall-wart, for instance.

Bud, W2RU


On Jun 26, 2012, at 6:36 AM, Greg Chartrand wrote:

> Last month I began a computer up-grade process at home and work by using solid state drives (SSD) in both laptop and desktop systems. The upgrades have been very successful providing a significant performance increase and extended battery life.  
> The last upgrade was my ham shack desktop system that I rebuilt with a new copy of Windows 7. All seemed well until I  turned the rig on and heard garbage and multiple birdies across the lower 50 khz on 160. 
> I was distracted for a week trying to recover a lost disk but I put the  SSD in place again yesterday. This time I wrapped the SSD in aluminium foil and put 2 clamp on cores on the SATA cable. I fired up my system, and the extra measures had no noticeable improvement on the birdie situation. The 
> birdies  appear as soon as I power up the drive.
>  I doubt if I will be able to remove the noise so this is a warning to those who may consider the same upgrade to their hamshack computer. My computer with the old fashion Hitachi hard drive contributes zero noise to my receiving capability on any band so SSD's are not in my future!
> Greg