In article ,
"Michael A. Terrell" wrote:

Telamon wrote:

In article ,
Doug Smith W9WI wrote:

Monroe wrote:
I'm not up on the tech side of 2-way wireless comm's. Solely Rx only
of the shortwave and longwave frequencies. But I am considering a
wireless alternative to my slow dial-up for internet connectivity.
The system is based around this device:


http://www.packetgods.com/store/prod...products_id=12
7

The wireless ISP rep indicated that the power over ethernet line had
resulted in intereference for some local HAM users, and suggested a
shielded cable and/or selective routing may solve the problem.

I've not heard of any problems with power-over-ethernet causing
interference to hams. (that said, this is the first I've heard of
power-over-ethernet period!)

Snip

Think of small switching power supplies running on 24 to 48 volts and
switching from 100 to 500 KHz. Bad news. Bad, bad, bad.


Not always bad. They were developed for industrial use to interface
with other systems. A poorly designed linear power supply can generate
a lot of noise if the diodes are cutting off fast enough to create
noise. A lot of designs use a small capacitor across the diode to swamp
the oscillation at the switching point. A well designed and shielded
switching supply can be very quiet. Just because it has a long power
line doesn't mean it has to create and radiate noise.

The idea is to be able to connect networked devices and also power them
over the ethernet cable.

Not popular yet and I hope it stays that way. It's been around a few
years now. Besides the noise generation potential its a lame idea anyway.

Well, it's supposed to be cheap way of doing things and you know what
that means. Poor filtering due to cost and no space to put the
components anyway in those little bricks.

--
Telamon
Ventura, California