On Fri, 31 Dec 2004 11:41:11 -0800 (PST), Martin AA6E wrote:
>Am I missing something?
I don't think you're missing a thing.
To respond to John's question, I'll point out that I did address
balanced power in the piece. The ONLY advantage of balanced power
is that equal voltages are applied to bypass capacitors within
equipment, as well as to other leakage capacitance that may be
hanging between the AC line and the equipment ground. For that
reason, the noise current in the ground has a better chance of
cancelling, so the ground is quieter. This can translate to less
current flowing on the shields of signal wiring, which in turn
results in less noise being induced into the audio (or video)
system.
Balanced power systems are, IMO, strongly over-rated and over-
touted. They are more "audio jewelery" for those who know a little
science (buzz words) but not enough to know they are being sold a
bill of goods.
I do agree with John that any electronic installation, including a
ham station, will benefit from a dedicated circuit for the reasons
you cite -- that is, it is less polluted by noise from other
loads, and suffers less voltage sag when some other heavy load
kicks in. That's because the only common conductors are the
(larger) feeders to the breaker panel, not the (smaller) branch
circuit conductors. And I also agree that shared neutrals are a
bad idea, for the same reason.
When I bought my 110-year-old house nearly 20 years ago, I put in
a lot of conduit and re-wired it to put IG outlets everywhere and
run dedicated phase, neutral, and IG home runs to every quad box.
My ham shack has a dedicated 20A 120VAC circuit, as well as a
dedicated 240VAC circuit. An air conditioner, sitting next to the
shack, is on another dedicated 20A circuit. My office computers
are on another dedicated circuit. And so on.
Each of my electronic systems goes first to a SurgeX unit, then
one or more multi-outlet strips. The computer rigs (mine and my
wife's, in different rooms) each has a SurgeX followed by a UPS.
The UPS's I use are Best Power (now called something else, thanks
to a corporate acquistion). The UPS for my ham station consists of
some big batteries that are float charged.
I also addressed "reactive power" in the form of the section on
harmonic current, which is really what is going on in electronic
gear. BTW -- in Europe, the harmonic content and power factor are
covered by some EU regulations. That isn't true in the US -- it's
between you and your power company, and you're only going to hear
from them if you're a BIG facility.
Jim Brown K9YC
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|