[Antennas] Open Wire Feedline

Sun Jan 27 01:50:06 EST 2013

Ken,
I first used the pen enclosures and they work fine. However, I now use a 
product I found at a local Tractor Supply store. they are called Fi-Shock 
insulators. I bought a box of 200 for about 15ドル. They are tough,very strong, 
rated to handle high voltage, transparent to RF, and are resistant to 
ultraviolet exposure, even the Texas sun. They are intended to use on electric 
fence runs where the wire runs through a staple on the fence post. Here is a 
link to their web site. _Fi-Shock Online Catalog_ 
(http://www.fishock.com/store/high-tensile-electric-fence/500-540) 
I left the Fi-Shocks at 4" It comes out to about 480 ohms. I'm sure you 
could find something cheaper in your local home improvement store. Free is 
always better though, and a lot more fun scrounging...
For the wire it depends on what I have around the shop. Normally I use #18 
insulated THHN. 
Also readily available at the local home improvement store. If you are 
like most hams, (or me anyway) I'd rather scrounge. Find you a local 
electrician that contracts out to larger companies doing major commercial work. They 
carry 1000' rolls and when it gets down to less than 200 hundred feet they 
will give it to you off there truck. Good luck and keep me posted on how 
it turns out for you.

Randy_KB4QQJ

In a message dated 1/26/2013 7:04:23 P.M. Eastern Standard Time, 
ken at wa0sbu.com writes:
I was hoping they would last long enough in the Texas sun. It would be 
nice to get "free" plastic tubes. I will have a least a 100" foot run, might 
take quite awhile to gather them up. What wire did you use Randy? Did 
you cut the pens down, 3" as in the video?
On 01/26/2013 05:28 PM, _KB4QQJ at aol.com_ (mailto:KB4QQJ at aol.com) wrote: 

If you want to perform a very basic check of the conductivity of your 
spacer, put it in the microwave for one minute. If it get "hot" to the touch it 
is not suitable for insulators. This being a very simple but basic test. 
The black pens I've used (papermate™)come out of the microwave at 93°f and 
have stood 600 watts and daily NC sun at my clubhouse for the last three 
years. It is a 41 foot section of openwire. Just my 2¢

Randy_KB4QQJ

In a message dated 1/26/2013 5:29:29 P.M. Eastern Standard Time, 
_n8de at thepoint.net_ (mailto:n8de at thepoint.net) writes:
think using BLACK spacers is a big mistake, as the chemical used to 
make the pen bodies BLACK is somewhat CONDUCTIVE ... and might break 
down under high power applications.
I prefer to use the plastic tubes that machine tool companies discard 
from drill bits. They are about 5 to 6 inches in length, somewhat 
transparent, and FREE, if you ask for them.
73
Don
N8DE