[ARC5] A flame against the imperial system - (was cost of sets)

[mstangelo at comcast.net]

I wouldn't blame the Japanese for odd component and connector dimensions. Many popular electronic components were designed in the US and the package dimenstions were specified in inches. That's why the common dip package pin spacing is 1/10 of and inch (2.54mm).

I found the best way of learning the metric system was to understand it without refering to the Imperial system. For example, a teacher would display a meter stick and claim 'this is a meter stick, a tenth is a decimeter, one hundreth is a centimeter" and so on. Saying a meter is 39.39 inches just confuses people.

I do, however, have one question about the Japanese adaption of the metric system. A common metric small screw size is M2.5. Many Japanese radios use M2.6 screws. Why did they adopt that size since it was so close to M2.5?

Mike N2MS

----- Original Message -----
From: Leslie Smith <vk2bcu at operamail.com>
To: Discussion of AN/ARC-5 military radio equipment. <arc5 at mailman.qth.net>
Sent: Fri, 24 Sep 2010 11:52:32 -0000 (UTC)
Subject: [ARC5] A flame against the imperial system - (was cost of sets)

<snip>

The ONE place where I prefer metrication is in PCB layout.  A pin spacing of 0.1 inches is a LOT more useful than 2.50mm, especially when it's a many element connector.  The Japs have bastardised the PCB system.  

Enough.  Best wishes from the theoretically metric Australia. 

Les