[TowerTalk] CQ article error(?)

[Michael Tope]

----- Original Message ----- 
From: "Ian White G/GM3SEK" <gm3sek at ifwtech.co.uk>

> Interesting... the power companies in the UK take a different view. In 
> the event of a neutral break in their local distribution system (230V 
> single-phase, neutral close to earth potential) they'd rather have the 
> return current flowing back through earth than create a shock hazard due 
> to the neutral becoming hot.
> 
> Therefore they almost always earth the neutral at the transformer, 
> and/or anyplace else they conveniently can. Having made that policy 
> decision a long time back, they have created the expectation that 
> neutral will be safe to touch when doing household wiring work, so now 
> they're perpetually locked into that policy.
> 
> 
As I recall, there are also rules in the UK (or at least there were
10 years ago) about shields on CATV drops being isolated between 
the customer premises end and the rest of the plant. Presumeably this 
is to keep neutral currents from the AC mains from flowing back to the 
source through the CATV plant. When I worked for a CATV 
manufacturer I had the opportunity to play with a number of these 
ground isolators. It turns out to be a real design challenge to break the 
shield at 50 Hz while providing a nearly continuous shield at RF 
frequencies. Most of the designs I tested leaked RF like a sieve. 

73 de Mike, W4EF..........................................