Message-ID: <1100885558.419e2e36ebc6a@webmail.ukonline.net>
Date: Fri, 19 Nov 2004 17:32:38 +0000
From: captbrian <captbrian@ukonline.co.uk>
To: rsgb_lf_group@blacksheep.org
References: <01C4CE0F.A626D2D0.actalbot@southsurf.com> <200411191419510430.03BFEEA7@mail.zetnet.co.uk>
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A specific part of engineering course at Cambridge in the 50"s was a clear 
grasp of the order of magnitude of things, it has stood me in good stead in all 
matters from ham radio thro' yacht navigation quite apart from earning a 
living..

bryan  G3GVB

Quoting John Rabson <word.factory@zetnet.co.uk>:

> On 19/11/2004 at 08:13 Andy wrote:
> 
> >When it comes to calculations, the most useful ability is not to be able
> >to
> >caculate it exactly, caculator or no, but to quickly be able to estimate a
> >ball
> >park answer or approximation.
> >
> >Who needs to know that  22uH at 137kHz has 18.93 ohms reactance.
> >
> >Its quicker to think  " a bit more than 20 times a bit less than 0.14,
> >times
> > 6-and-a-bit
> >...    is  2.8 times 6-and-a-bit ,  so call it 18 ohms"
> >
> >And they don't teach that in schools - and never have done, to my
> >knowledge!
> >
> >Andy  G4JNT
> I seem to recall a telecommunications professor (Ken Cattermole?) who
> expected his MSc students at least to have a feel for whether a result was of
> the right order of magnitude.
> 
> John G3PAI
> 
> 
> 
> 
> 


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