[arm-allstar] Noise from BBB

[Dave Miller]

Yes you would need to run them at close to full rated load or at least at the expected load to get a fair indication.  
Running unloaded they will be in discontinuous mode that can be very quiet.  
Dave
VE7PKE

Sent from my iPhone

> On Apr 30, 2015, at 1:29 PM, David McGough <kb4fxc at inttek.net> wrote:
> 
> 
> 
> 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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