Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Highest AWG to safely support 1KW RF  (Read 659 times)
KA3DNR
Member

Posts: 74




Ignore
« on: October 13, 2009, 09:36:13 AM »

Hello Elmers,

And, thanks, as always, for your help!

I am going to put up a stealth wire,and need to know what is the highest AWG that can handle 1KW CW.

Your thoughts?

Regards,

Marc
Logged
AD4U
Member

Posts: 2186




Ignore
« Reply #1 on: October 13, 2009, 10:27:25 AM »

Probably most any AWG wire that will support itself will "handle" a KW.  Seriously a better question would be.....considering wind, ice, etc, what AWG wire will stay up and not pop.

Dick  AD4U
Logged
WB2WIK
Member

Posts: 20666




Ignore
« Reply #2 on: October 13, 2009, 11:23:27 AM »

I agree with Dick.  Even #26AWG or so should handle a kilowatt (in free air). The "danger" is more from arching to flammables at the high voltage points of the wire, which are always the "very end" (far tip) of any wire antenna, and then again 1/2-wave back from that point (and 1-WL back, and 1.5-WL back, etc).

And of course the obvious, which is the wire needs to be strong enough to not break.
Logged
KA3DNR
Member

Posts: 74




Ignore
« Reply #3 on: October 13, 2009, 11:31:56 AM »

Great. What is the highest AWG that won't break? Let's say it's a loop, little to no wind, never snows, rains sometimes...It's San Diego, after all.

m
Logged
AD4U
Member

Posts: 2186




Ignore
« Reply #4 on: October 13, 2009, 12:00:14 PM »

Marc - that is a loaded question to which nobody can give a definite answer.  It all depends.........on so many different variables.  

It depends on how big a loop you want to put up.  It depends on how many supports you intend to use to hold the wire up. If you plan to put up a 10 meter loop, I would give one answer.  If you plan to put up an 80 meter loop, I would give you another answer.

I could go on and on, but I think you get the message.  Personally I would put up the largest AWG wire that you think you can get away with considering all your restrictions.  If it breaks, then re-install the antenna using larger AWG wire.

Dick  AD4U
Logged
AD4U
Member

Posts: 2186




Ignore
« Reply #5 on: October 13, 2009, 12:08:10 PM »

PS:  If you have to go with small diameter wire, I would only use soft drawn, single strand, enameled or bare copper "magnet" wire as a last resort.  It does not have much strength and it s-t-r-e-t-c-h-e-s.  

Contact The Wireman or some other wire dealer closer to you.  Tell them you problem and ask if they have some kind of small diameter stranded antenna wire with perhaps a core of stronger wire than copper.  The copper wire in this stranded stuff is the better RF conductor and the steel or other wire imbeded in it gives it strength.  Then there is always copperweld wire if you can find it in small enough diameter.

This stuff is available, but you may have to look for it.

Dick  AD4U
Logged
N3OX
Member

Posts: 8847


WWW

Ignore
« Reply #6 on: October 13, 2009, 01:37:04 PM »

"PS: If you have to go with small diameter wire, I would only use soft drawn, single strand, enameled or bare copper "magnet" wire as a last resort. It does not have much strength and it s-t-r-e-t-c-h-e-s."

I used a magnet wire doublet with a remote tuner at the feedpoint knowing I would have to replace the wire and re-learn tuner settings occasionally.

I think it was 30 gauge and it was just shot into a couple of trees and only broke a leg once a year or less.

The danger of course is that it breaks right when you need it ;-)

I agree that it's a last resort but it's not a terrible one if you need that level of stealth.

73
Dan
Logged

73,
Dan
http://www.n3ox.net

Monkey/silicon cyborg, beeping at rocks since 1995.
WB2WIK
Member

Posts: 20666




Ignore
« Reply #7 on: October 13, 2009, 03:05:32 PM »

>RE: Highest AWG to safely support 1KW RF       Reply
by KA3DNR on October 13, 2009    Mail this to a friend!
Great. What is the highest AWG that won't break? Let's say it's a loop, little to no wind, never snows, rains sometimes...It's San Diego, after all.<

::Depends on a lot of stuff.  Any trees used as supports?  If so, they sway.  If the wire is outside and horizontal, birds can land on it, no matter how small it is.  I don't know how birds can see a skinny wire and decide to perch on it, but they certainly seem to do that.

Copperclad steel is obviously a lot stronger than pure copper and would be my first choice for a small gauge outdoor antenna (for survivability).  I think #18AWG copperclad is at least as strong as #14AWG copper.

WB2WIK/6
Logged
KB1LKR
Member

Posts: 1898




Ignore
« Reply #8 on: October 13, 2009, 03:17:02 PM »

What kind of wire? Stainless steel? Copper clad steel? Copper (hard drawn or annealed)? Other?

Copper clad steel wire w/ a spring or weight for tension would probably be best. Try 18 AWG copperclad (#510 or #532) from The WireMan or other vendor, he also has 26 AWG copperclad (#534), but it's not particularly strong only 25 lb break.

Boy, little wind, no snow,ice, sleet, etc. (not much lightning and no hail, either?) what a dull place to live <grin>.
Logged
K7KBN
Member

Posts: 2835




Ignore
« Reply #9 on: October 13, 2009, 04:51:04 PM »

A little experimenting never hurt.  Good way to learn.

73
Pat K7KBN
Logged

73
Pat K7KBN
CWO4 USNR Ret.
K9FON
Member

Posts: 1012




Ignore
« Reply #10 on: October 13, 2009, 04:52:31 PM »

I had some old railroad telegraph line wire that was given to me a few years ago. I dont know what guage it was, but boy was it ever strong! I think it was copperweld wire.
Logged
WA3SKN
Member

Posts: 5555




Ignore
« Reply #11 on: October 14, 2009, 07:38:12 AM »

Stealthy, hidden antenna wire?... take a look at stranded stainless steel fishing line.  You can get it in 30 lb test and above.  You won't be able to solder to it, so plan to use crimp connections or alligator clips.
It is strong and nearly invisable.  I don't see much in the way of trees in your area.  At least the power appears to be underground.  You might even try using it with a kite or ballon!
And use cutters for steel when working with it!
You can find it a salt-water fishing shops.
73s.

-Mike.
Logged
N1LO
Member

Posts: 1039


WWW

Ignore
« Reply #12 on: October 14, 2009, 10:51:54 AM »

I'd say 24 gauge, insulated.

--...MARK_N1LO...--
Logged
K5LXP
Member

Posts: 4536


WWW

Ignore
« Reply #13 on: October 14, 2009, 11:18:31 AM »

Unless it's an extreme span or you're supporting a heavy feedline, I'm with N1LO.  A light gauge stranded wire can go a long way, won't cost much if anything at all and will likely last long enough to outlive its usefulness.

I hate copperweld.  It's a real pain to work with.  Same goes for that aluminum clad wire that my Hy-Gain dipole is made of.  For a permanent antenna I would recommend FlexWeave:

http://www.davisrf.com/flexweave.php

The 14ga is more than plenty strong for any antenna I've ever built.  Many commercially available antennas use FlexWeave.

I usually do prototypes using inexpensive stranded wire and when I come up with a winning configuration that's when I can commit to making a version out of FlexWeave.  More often than not the inexpensive wire version lasts long enough.


Mark K5LXP
Albuquerque, NM
Logged
KA3DNR
Member

Posts: 74




Ignore
« Reply #14 on: October 14, 2009, 11:30:28 AM »

Gentlemen,

Thank you, thank you, thank you...

Excellent thread. I have printed it out.

Regards,

Marc
San Diego
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!