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Re: [Amps] Metric system

To: amps@contesting.com
Subject: Re: [Amps] Metric system
From: Tony King - W4ZT <amps@w4zt.com>
Date: Thu, 04 Aug 2005 13:03:36 -0400
List-post: <mailto:amps@contesting.com>
I agree with George :)

I also have micrometers and dial indicators that can measure to 1/1000 
and 1/10000 inch.  My lathe and milling machines have dials that read 
.001 inch.

It's easy to use metrics.  Comes in handy when I compare wavelength to 
frequency. On the other hand, I learned to use powers of ten long before 
metrics were "cool".  It doesn't matter one bit whether we use metric or 
English measurements.  I learned how to convert between the two long 
ago. The most important thing we need to remember is to not waste our 
time with expectations of too much accuracy.  When the project says cut 
the antenna 19-1/4 inches long, use a tape measure. If I specify 2-3/8 
inches, do the math if you want it in millimeters.  If George says it's 
1.0325 inches, you'd better get out the micrometer.  On the other hand, 
if Jos specifies 12 millimeters, I think 0.47 inches will be close 
enough unless he specifies a closer tolerance.  I don't think I'm going 
to try to achieve 0.4724395 inches.

Sounds like it would have been a good antenna George, useful on a wider 
range of frequencies!

Which pole, magnetic or geographic?  ;)

73, Tony W4ZT


w5grg wrote:
> The US adopted the metric system in the late 1800's.
> If you understand tolerances and the various systems of measurement, the 
> English system is really better for common work, you can't beat 
> fractions. Also, how do you order 1/2 of a pie at the bakery in the 
> metric system .5 of a pie?
> Those schooled in the metric system think it is more "accurate" being 
> base 10 only. The English system is base 2, 3 and 10, I have an entire 
> machinists chest of micrometers, dial indicators, etc all marked in 
> 1/1000 or 1/10000 of an INCH. What about a pints a pound the world around?
> I was trying to build a 2M antenna out of the 2001 Handbook, the 
> dimensions are in MM, but I could never get it done, I would cut the 
> elements off to the correct MM length in the morning, but by afternoon 
> and 100 degree heat, they were too many MM long, so I had to cut them 
> again,next morning, I checked and they were too short so I had to throw 
> them all away and start again. I think I will go crazy building the 
> antenna, maybe I will just get a premade one and stop trying, hopefully 
> the instructions will be in English.
> I wonder how far it really is the the North Pole?
> Thanks, George W5GRG

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