Gee Jim, I didn't think I was *that* stupid. Yes, I didn't get the
decimal places right -that was a simple brain phart. As for the
licensing tests, did you have to draw a Colpitts oscillator? IIRC, that
was on my General exam in 1955.
With the power strip, what's wrong with measuring the voltage in and
out, knowing the current being drawn, and deriving the resistance from
that?
73, Pete N4ZR
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at <http://reversebeacon.net>, now
spotting RTTY activity worldwide.
For spots, please use your favorite
"retail" DX cluster.
On 4/26/2020 6:24 PM, Jim Brown wrote:
I wouldn't expect useful accuracy from anything but a lab instrument
for such low resistances as a few feet of #12. Far better to look up
the resistance of copper wire from a wire table. An unknown "black
box" like a power strip is not so easy. :) As for the protection
diode, that's pretty easy too -- look up the junction voltage for that
type of diode, and you're within 0.1 volt of reality.
The thing I find baffling (or depressing) here is that we all had to
understand Ohm's Law to pass the exam for our license, and it's REAL
simple. Take resistance values from a wire table, multiply by the
length, then by two for the two conductors, then by the current. I
dunno what the exam is like nowadays -- my experience was 1955 with
the Novice test and a year later with the General -- but surely there
must be something about how diodes work!
73, Jim K9YC
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