[Lowfer] GROUND RESISTANCE

[Howell, Laurence (Shanghai/Singapore)]

My pennies worth - Id go for a BIG and high a loop as possible - keep
the RF resistances down by using multiple wires, bundles or something to
keep the RF resistance down and still worth having a conductor that does
have a reasonable insulation sheath so your conductor isn't directly
connected to the woodwork - there is still enough voltage there to cause
detuning and or charcoal. If your using capacitors to tune the sucker
share the current loads by using multiple parallel low loss types to
stop heating and detuning to some extent.

I followed loopy Bills notes and the experiences of others but if you
have strong enough trees Id go for it - The detuning effecting of the
trees, the weather etc or lack of them made it an easier ride than a
vertical whereby I would have found it difficult to control a lot of the
changing parameters or at least engineer them out.

My loop carried something approaching 50A  of 137 kHz current so it was
a steep "heating" learning curve - and I have no doubt my more slender
silver birch trees in Alaska are going to be a challenge.

http://www.kl1x.com/loop1500.jpg
http://www.kl1x.com/house.jpg
http://www.kl1x.com/newloop.jpg


Laurence BY3A-KL1X
Tanggu China

-----Original Message-----
From: lowfer-bounces at mailman.qth.net
[mailto:lowfer-bounces at mailman.qth.net] On Behalf Of rick
Sent: Saturday, January 03, 2009 12:07 AM
To: Discussion of the Lowfer (US, European, & UK) and MedFer bands
Subject: Re: [Lowfer] GROUND RESISTANCE


Thanks Peter !
 Well the only spots on my lot that are treeless are where my house and
my 
swimming pool are. I dont think the xyl wouild like an antenna in either
of 
those spots.
 So yes I will keep you posted on my loop progress.

                    73
                         Rick KA2PBO







----- Original Message ----- 
From: "Peter Barick" <pbarick at niu.edu>
To: <lowfer at mailman.qth.net>
Sent: Friday, January 02, 2009 10:48 AM
Subject: Re: [Lowfer] GROUND RESISTANCE


Rick,
Re: Your Antenna Choice

Given your assessment of local soil conditions (bleak) the choice most 
likely is a loop and based on Bill's proven works on the subject.

An easy choice appears to be a loaded vertical, but at LF performance is

hard to come by, given the low power allowed (Part-15). From experience
of 
setting up a LF vertical it's a big job and easily compromised given
near-by 
trees and other conducting objects we people like to live with. Plus
there's 
the ground radials, yes. need more than a few 10-foot ground rods at the

feed point. I made a choice to lay out many on top of ground (a
veritable 
land mine at night !). Yes it worked but at a higher cost of real
estate, 
trees cut down and risk of RF absorption by yet other trees when sap is
up. 
Ha, the one advantage left is the omni-directional quality vs the loop.

That's just my take, given my circumstances, of course. And it didn't
begin 
with a grand plan -- just sorta evolved based on perceived need.

So if you have suitable trees and a means of dragging up a tow line at
least 
50-feet high, go for a 50x50 foot loop. Oh, and keep us posted on
progress.

- Peter
-------------------------------------
>>> Mike-WE0H <we0h at yahoo.com> 01/02/09 12:30 AM >>>
Good to hear that Rick. No worries about tree loss or any significant
ground issues with the Ashlock loop. It will work. Keep those
connections perfect and use De-oxit or Vaseline on those connections so
they stay clean and low resistance. You will be impressed with the
loop's performance.
Mike
----------------------------------
rick wrote:
> Thanks Andy,
> Appreciate the info.I just finished reading  Bill Ashlocks papers on
> loop antenna .I trhink thats the way Im gonna go .It seems like alot
< ... >
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