REFLECTOR: i pad / radio noise

[Brian Michalk]

Your best bet is to buy one with good recommendations.
I like shopping at newegg, and when I can't determine reliability from 
specs, I'll go with highest ratings.  But it also has to be from many 
people.

For example Product A has 5 stars from 10 people.
Product B has four stars from 100 people.

I go with product B, because the five people could be paid shills.

On 09/08/2013 02:17 PM, John Dibble wrote:
> On 9/8/2013 12:04 PM, Brian Michalk wrote:
>> I had a power adapter screw with my car. I bought another one, and 
>> the problem went away.
>>
>> When I build my circuit boards, the biggest noise problem I have is 
>> when a voltage regulator oscillates.  It either needs more 
>> capacitance, or a lower resistance (ESR) capacitor to prevent the 
>> oscillation.
>>
>> I suggest getting a new power adapter.
>
> Would a more expensive adapter work better?  Or a certain brand?
>
> Thanks,
>
> John
>>   If that is not an option, take it apart and add some ceramic caps 
>> to any caps that already exist.  Kind of difficult if you don't have 
>> an oscilloscope.
>>
>> No, shielding the cord most likely won't help.  I'll bet it's noise 
>> injected into the power lines in the form of voltage spikes.  It's 
>> not a radiation problem like magnetic or RF.
>>
>> On 09/08/2013 08:13 AM, John Dibble wrote:
>>> I now understand why there is concern with the use of personal 
>>> electronics on commercial aircraft. Previously I reported erratic 
>>> radio noise.  It was the same noise as I get when I pull the volume 
>>> knob to receive weak signals.  Also my nav was not picking up VORs 
>>> very well. After a long discussion with an avionics technician I 
>>> decided to investigate my i pad.  He said that because it's not 
>>> shielded, it can interfere.  I had a hard time believing that 
>>> because many are using the i pad and no one else is complaining. 
>>> However, I'm using a power adapter and he said that can be a problem 
>>> also. So I tried unplugging the power adapter and, sure enough, the 
>>> radio noise went away.  Also the nav came alive and picked up VORs 
>>> like it should.  I also found that if I turned off the alternator, I 
>>> could leave the power adapter plugged in and the radio noise was 
>>> gone.  This did not eliminate the nav problem, however.  So now I'm 
>>> turning to the electronics wizards in the group to see if there is 
>>> any way I can have my power adapter and use it too. Would insulation 
>>> around the power cord help?
>>>
>>> Thanks,
>>>
>>> John
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