Maybe that a pk to pk reading with your shack O-Scope and do the math
to find the RMS, Average, etc.|
Pete Smith wrote:
At 11:07 AM 1/24/2005, W8JI wrote:
So you need two meters Pete...you need to measure the true
peak and you need to measure the true RMS. Capacitor input
supplies run off the peak, and are more sensitive to line
ESR at a given power load than resistive loads like choke
input supplies or filaments.
Thanks to Tom and everyone else who wrote. Yes, Tom's right about 110
vs 120 -- somewhere 50 years or so ago I formed the mental habit of
calling it "110." That was appropriate at the time, I think. I'm told
the current ANSI spec is 120/240 +/- 5 percent.
Not having either a true RMS and true peak meter, I intend to follow the
advice of some others and verify that the two legs of the service are
within a volt or two of each other at the panel, and let the power
company put a recording voltmeter on the service to see if the problem
is there. Frankly, I'm betting on that, because our power company is in
Chapter 11 and the county's population is growing fast. I'm only a
couple of miles from the substation, but it's one that serves a lot of
the population growth. The extreme lows I've noticed are all relatively
early in the morning, which suggests a peak load for heat pumps,
I just measured a 110 outlet close to the panel and the voltage was
111.1 Upstairs, about 60 feet of wire away, with the two radios on
receive, I measured 110.1. Turning off all the "radio" side (radios,
rotator and stack controllers, etc.) it went up to 110.8. Just now it
hit 111.7 in the shack for a moment -- now 110.2. Lots of fluctuation.
I don't know if these are either RMS or peak voltages (most likely some
fudged version, because it's not a Fluke).
Assuming the wiring is #14, my Handbook says the resistance is .252 ohms
per 100 feet. Measuring at an outlet in the shack, equipment in the
shack is drawing through ~120 feet of that wire, right? That doesn't
sound wildly off to me.
Or have I misunderstood something fundamental? Wouldn't be the first time.
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
any questions and ask for Sherman, W2FLA.
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See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
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