[Amps] Metric system

[Osten B Magnusson]

Use a conversion tool  -   I'm sure there are
some available on the Internet - even the
log-program Logger has one built in.

73 de Osten  SM5DQC    sm5dqc at areteadsl.se


----- Original Message ----- 
From: "Patrick Hoppe" <phoppe at wi.rr.com>
To: "'Dr. David Kirkby'" <david.kirkby at onetel.net>; <amps at contesting.com>
Sent: Thursday, August 04, 2005 7:00 PM
Subject: Re: [Amps] Metric system


> Give these metric guys 2.54 cm and they will take 1.6 km...
> 
> Pat
> 
> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
> Behalf Of Dr. David Kirkby
> Sent: Thursday, August 04, 2005 11:24 AM
> To: amps at contesting.com
> Subject: Re: [Amps] Metric system
> 
> Keith Dutson wrote:
>>>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.
>> 
>> Most measurements are specified at standard ambient temperature and
> pressure
>> (STP).  In layman's terms this means the measurement should be taken at
> room
>> temperature (70ish F) and sea level (29.5ish in Hg).  Obviously, for
> metals,
>> the pressure is not a significant factor.
>> 
>> 73, Keith
> 
> Nor is temperature going to be when making a 2m antenna. The expansion of
> the metal will not be 
> measurable with a ruler (they will both expand at about the same rate), but
> furthermore, fractional 
> changes in length will be small compared to the fractional changes of
> frequency you will make.
> 
> I can't see why people (especially hams, most of whome have an IQ > 80) have
> difficulty with the 
> metric system.
> 
> Most (well the semi-intelligent ones anyway) seem to be able to handle the
> fact there are 1000 milli 
> Ohms in an Ohm, 1000 Ohms in a 1 kOhm, 1000 kOhms in a 1 MOhm. Some may even
> use Giga Ohms 
> occasionally, although they are not used that often.
> 
> So what is the big deal about 1000nm = 1 um, 1000 um = 1mm, 1000mm = 1m,
> 1000m = 1km etc?
> 
> If someone said lets use some measurements for resistance, that were not
> based on multiples of 1000, 
> but something like
> 
> 12 Ohms is a Yonk (equivalent to 12" is a foot)
> 3 Yonks are a Foobar (equivalent to 3 feet is a yard)
> 1760 Foobars are a Spanner (equivalent to the stupidty of 1760 yards in a
> mile)
> 
> That makes 1 spanner equal to 63,360 Ohms.
> 
> I think most would think it a stupid idea, and prefer to stick to mOhm,
> Ohms, kOhms, MOhms and GOhms, 
> which have nice sensible ratios of 1000 between them.
> 
> You can work in ratios of 1000 for resistance, inductance, capacitance,
> voltage, current etc,  so why 
> not do the same for length, mass, force etc? Any attempt to change those
> ratios of 1000 would be 
> resisted by most.
> 
> Of course, we could always base the unit of capacitance equal to the
> capacitance between the earth and 
> the Sun. Then the Sun-mercury capacitance would be larger (I expect) and the
> Sun venus capacitance 
> would be smaller (I expect). I say "I expect", since you would need to know
> the distance as well as 
> diameter, and I can't be bothered to sit and work these things out.
> 
> Come on, accept that metric is more logical and use it!!!
> 
> 
> 
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> 
> 
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