Re: 150Khz Antenna question

"Joerg" <notthisjoergsch@[EMAIL PROTECTED]
> wrote in message 
news:r7Pak.8821$89.4911@[EMAIL PROTECTED]
> Tom Bruhns wrote:
>> On Jul 2, 7:29 am, "Jacques St-Pierre" <multe...@[EMAIL PROTECTED]
>
>> wrote:
>>> Anyone can help me with the design of a compact 150Khz antenna?
>>>

.. . . snippity snip . . .

>
> Back at the university I always wondered about that: Immature fields
(near 
> field), juvenile fields, adolescent fields? So where does an EM field 
> reach puberty?
>
> :-)
>
> -- 
> SCNR, Joerg


John Kraus gave a workable definition in his book 'Antennas', that the 
[appropriately] normalised magnitudes of the different field components 
(reactive and radiation) are all equal to pi at a distance lambda/2.pi
away 
from the 'antenna' so, closer than that, the 1/r^2 and 1/r^3 reactive
terms 
dominate, and further away the 1/r radiation terms dominate.

So the larger value of lambda/2.pi can be taken as the bare minimum 
separation of two simple antennas intended to operate independently.  Of 
course, there will still be major coupling between them on account of 
radiation (TX) or re-radiation (RX) and gainful antennas demand 
pro****tionately more separation in their line(s) of fire.

Chris