[ARC5] Adventures in Battery Ops - filters.

[Scott Robinson]

Further such tale, about a much smaller supply:

I have an old  Motorola Razr cell phone that I bought used. I then 
bought an aftermarket charger for it, and it significantly raised the SW 
band noise floor, even when plugged in about 30 feet from the receiver 
and antenna.

I then looked on eBay and bought a real Motorola charger, which makes 
*no* noise that I can hear.

I still have the other charger as a backup, and, the last BBC 
transmitter I could hear (form Thailand, and I'm near San Francisco) 
having gone off the air, I could use it and not affect my life but don't.

The really cheap stuff will be illegal (doesn't pass FCC) but the mfr is 
in Asia and doesn't care.

Regards,

Scott

PS--experience on my bench is that LED light bulbs are much quieter than 
CFLs...but that may be because they cost $20 instead of $2.

On 4/10/15 9:21 AM, Kenneth G. Gordon wrote:
> Bill (and group):
>
> Some time ago, your middle son, who at that time knew everything (I'm not
> young enough to know everything) decided to build himself a hot-rod 'pooter
> using parts which were as inexpensive as possible.
>
> One of those items was a "really powerful" 600 watt power supply.
>
> As soon as he fired his new creation up, every single radio and TV in the
> house exhibited horrendous noise.
>
> I was not aware what he had done, so I got out a small AM radio with a
> loopstick antenna in it and went "looking".
>
> It didn't take long to zero in on his new 'pooter.
>
> I removed the power supply while he was gone, opened it up and took a
> look. It was the cheapest looking thing I have ever seen, the case metal
> being about as thick as that in an aluminum beer can, and, of course, there
> were ZERO filters in it, although, like you, I found silk-screened places on
> what passed for a circuit board where those parts should have been.
>
> After buying and replacing that POS with a real power supply, I took the
> errant supply to a friend's target range.
>
> Several magzines full of 7.62 X 54R applied to the POS from 50 feet or so
> was a very satisfying experience for me.
>
> Ken W7EKB
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>