Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

Re: LF: Earth-mode or not earth-mode

To: "[email protected]" <[email protected]>
Subject: Re: LF: Earth-mode or not earth-mode
From: Jacek Lipkowski <[email protected]>
Date: Sat, 5 Feb 2011 12:05:30 +0100 (CET)
In-reply-to: <[email protected]>
References: <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]> <[email protected]>
Reply-to: [email protected]
Sender: [email protected]

On Sat, 5 Feb 2011, Roger Lapthorn wrote:

Gas pipes are non-metallic I think?

i think the high pressure pipelines are metallic.

Not sure I like the idea of connecting many watts of VLF power into high voltage pylons or gas pipes. In the UK we would be locked up as suspected terrorists!

hey, no risk - no fun :)

Having a few watts VLF piggyback a water pipe connected to my central heating radiators sounds as if it should be more legitimate. After all, we use such connections often as the ground systems for verticals.

it's probably not any more or less legal coupling vlf or hf to them.

btw. try a phone line. if you have an old wire infrastructure the wire will be grounded at the phone exchange far away. you can couple a few mA of VLF current to the grounded wire. 1km of wire really works wonders as a transmit antenna, but i'm sure that this is illegal (at least here the phone line is property of the phone company, and only accepted equipment can be connected to it).

This raises the question about the legality of putting VLF signals along utilities - is this actually permitted? After all, there are intercoms and data systems that intentionally use the mains electricity wiring. Anyone know what IS permitted?

if it isn't forbidden, then it's permitted. unless you ask for permission, of course, then legislation might be added to take the posibillity away from you.

if you don't conenct to the utilies directly, but couple to them, then i think it is legal. there are specific laws that describe the permitted electromagnetic field strength. these laws are carefully written, so that the power infrastructure is exempt from these laws (or otherwise they would fail), this is achieved by defining the lowest frequency. in Poland, and probably elsewhere too, these laws work from 30kHz up, so <9kHz is exempt. making a direct connection might still be illegal, but not due to electromagnetic emission, but due to tresspassing laws etc. but i'm not sure they work, since i haven't seen any signs saying that you can't get near the pylons. btw it will be very hard for you to generate a bigger field strength than the power line is already generating.

jacek




<Prev in Thread] Current Thread [Next in Thread>