[arm-allstar] Noise from BBB

[David McGough]

Oh, BTW, the noisy 19V laptop switchers I mentioned, below, are
completely quiet UNTIL I place a load on them. So, just unplugging the BBB
load doesn't necessarily eliminate the Wal-wart as the noise source.



On Thu, 30 Apr 2015, David McGough wrote:

> 
> Hi Robert,
> 
> Recent Wal-warts can be awful, awful, awful noise sources! I've even got a
> some 19V laptop power supplies that wipe out HF---S9+20 broadband noise
> on 75meters. The noise is coupled to the house wiring via the AC source. 
> The noise is everywhere!
> 
> As I've mentioned in other messages, I -highly- recommend these cheap
> DC-DC step-down switchers. I'm now using them 100% for BBB, RPi2 and
> Odroid C1 power supplies, with outstanding results. See:
> 
> >From China (these have taken about 2 weeks shipping for me):
> http://www.ebay.com/itm/251564887056
> 
> Previously, I've also purchased "the same" power modules from the US ebay 
> seller: NYPLATFORM  ...But, they seem out-of-stock right now. This seller 
> had about 2 day shipping.
> 
> Note that I'm using wal-warts to power these DC-DC switchers, too, in
> several setups.  However, I'm using "old style" (read that as: QUIET!),
> unregulated, transformer 9VDC to 15VDC 1A supplies. These warts are
> nothing fancy: a step-down transformer, full-wave bridge rectifier, and
> output filter capacitor....But, they're QUIET (and they're cheap!).
> 
> 73, David KB4FXC
> 
> 
> 
> 
> 
> On Thu, 30 Apr 2015, Robert Newberry wrote:
> 
> > So my home node of 6m gets kerchunked.  I have this constant level of
> > noise. This is observed as I park in my driveway and the noise gets picked
> > up next to me house. I went to the basement and flipped breakers. My ham
> > shack was the culprits. One source is an old micronta 12 power supply. Ok
> > so I unplugged that. The second Source is my BBB. I pulled the barrel plug
> > and thr noise goes away. So my guess is if it was the walwart it would of
> > kept up since I killed the power to the BBB. I also removed the plug for
> > the USB URI.
> > 
> > Has anyone experienced noise from their BBB?
> > 
> > N1XBM
> > Apparare Scientor
> > Paratus Communicare
> > Allstar Node # 27086, 41540, 41812
> > 
> 
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