Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old January 6th 04, 07:19 PM
Richard Clark
 
Posts: n/a
Default

On Tue, 6 Jan 2004 13:14:01 -0500, "w4jle" W4JLE(remove this to
wrote:
I would venture to say we all operate in the near field. How does one avoid
it, particularly on 160 meters?


Hi OM,

The greater part of risk is in the wavelength compared to body height.
Sitting down obviously lowers risk.

Now, for the standing individual of average size, that person is
approaching a quarter wave at 10M (especially if you are a fat
conductor). If you were the standard 1 wavelength away from a 100W
transmission, then the standard 22dB down would be your exposure and
you would experience something less of 1 watt of heating throughout
your body. Touch a christmas tree bulb (7.5W) and ask yourself how
uncomfortable that feels, then average that over your 2M² surface
area.

At 160M, you certainly stand the risk of being much closer than 1
wavelength, but you also stand less risk of being a quarter wave tall
(towering egos do not conduct). In any event, you are probably
sitting down anyway. Your radiation resistance in that band makes you
nearly invisible to the power emitted. Those standing next to VOA
half megawatt towers need to check their insurance clauses covering
acts of incipient stupidity.

73's
Richard Clark, KB7QHC
  #2   Report Post  
Old January 6th 04, 08:28 PM
Cecil Moore
 
Posts: n/a
Default

Richard Clark wrote:
Now, for the standing individual of average size, that person is
approaching a quarter wave at 10M ...


Unless the individual is grounded at one end, that 1/4WL is
non-resonant. :-) Richard, what is your velocity factor?
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----
  #3   Report Post  
Old January 6th 04, 08:33 PM
Richard Clark
 
Posts: n/a
Default

On Tue, 06 Jan 2004 14:28:06 -0600, Cecil Moore
wrote:
Unless the individual is grounded at one end, that 1/4WL is
non-resonant. :-) Richard, what is your velocity factor?


I can see why you ask about velocity if you are not on ground.
  #4   Report Post  
Old January 6th 04, 08:38 PM
Cecil Moore
 
Posts: n/a
Default

Richard Clark wrote:

On Tue, 06 Jan 2004 14:28:06 -0600, Cecil Moore
wrote:

Unless the individual is grounded at one end, that 1/4WL is
non-resonant. :-) Richard, what is your velocity factor?


I can see why you ask about velocity if you are not on ground.


"On ground" and "at ground potential" are very different things.
I wear thick rubber soles on my shoes forcing a current near-minimum
at each of my ends. And no, my feet are not big enough to cause a
microfarad of capacitance through an inch of rubber.
--
73, Cecil http://www.qsl.net/w5dxp



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----
  #5   Report Post  
Old January 6th 04, 10:12 PM
Richard Clark
 
Posts: n/a
Default

On Tue, 06 Jan 2004 14:38:16 -0600, Cecil Moore
wrote:
"On ground" and "at ground potential" are very different things.
I wear thick rubber soles on my shoes forcing a current near-minimum
at each of my ends. And no, my feet are not big enough to cause a
microfarad of capacitance through an inch of rubber.


Are you REALLY that concerned about less than 1W? Perhaps you should
wear Doc Martins.


  #6   Report Post  
Old January 6th 04, 11:05 PM
Steve Nosko
 
Posts: n/a
Default


"Cecil Moore" wrote in message
...
...
...And no, my feet are not big enough to cause a
microfarad of capacitance through an inch of rubber.
-- 73, Cecil http://www.qsl.net/w5dxp



Ahhh! But what about the other end?

The devil made me say this.
Sorry Cecil, just couldn't resist.
Steve K:9:C:I


  #7   Report Post  
Old January 6th 04, 08:42 PM
Dave Shrader
 
Posts: n/a
Default

Cecil Moore wrote:

Richard Clark wrote:

Now, for the standing individual of average size, that person is
approaching a quarter wave at 10M ...



Unless the individual is grounded at one end, that 1/4WL is
non-resonant. :-) Richard, what is your velocity factor?


I don't know about Richard but my velocity factor seriously deteriorated
after age 60 :-)

OOOPPPSSS!! Did I say that :-) Deacon Dave

Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Ethernet "thicknet" coax thru walls of house for ham radio antenna Robert Casey Antenna 8 January 18th 04 09:11 PM
Keeping moisture out of 9913 type coax? Dave Woolf Antenna 15 January 5th 04 03:52 AM
Poor quality low + High TV channels? How much dB in Preamp? lbbs Antenna 16 December 13th 03 03:01 PM
Burying Coax yea right Antenna 23 October 26th 03 08:12 AM
Length of Coax Affecting Incident Power to Meter? Dr. Slick Antenna 140 August 18th 03 08:17 PM


All times are GMT +1. The time now is 07:14 PM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017