| Author |
Message |
    
ncrebel
| | Posted on Thursday, March 21, 2002 - 2:05 pm: | 
|
Hey,I would like to know how to make a homemade CB
antenna out of wire.I know it can be done,I just don't know exactly what wire to use and how long to cut it.Thanks |
Viking
| | Posted on Thursday, March 21, 2002 - 6:17 pm: |
|
Here's a simple sloping dipole.
http://11-meter.com/projects/sloping_dipole.html
I did the same thing using coax. One end with coax connector to the radio (or preferably meter to verify SWR) and the other end...
9 feet from the end, remove the out coating (you now see 9feet of copper braid). remove 8 feet 10 inches of the copper braid from the end (leaves 2 inches). Separate this 2 inch end from the center lead and solder on about 8 feet 10 inches of 10 (or so) gauge wire.
Your coax now has 2 9-foot ends. set it up like the picture in the link. You may also want to make about 4 turns at about 6" diameter on the coax right before the split.
have fun |
ncrebel
| | Posted on Thursday, March 21, 2002 - 9:22 pm: |
|
Thanks. |
Straycat
| | Posted on Thursday, March 21, 2002 - 9:24 pm: |
|
Heres a simple vertical. Take an 18 foot piece of coax and cut off one of the PL259's. At that end remove 9 ft of the outer vinly sleeve. you'll now have a 9 ft piece of coax with braid exposed. At the base of the braid work a small sapce by pulling at the braid to separate it. Pull the inner conductor plastic coating and all out of this hole. It takes time (10-15 minutes or do) but it's worth it. When you have the center pulled out you'll now have a 9ft braid and a 9 ft center conductor hanging fron the bottom of where you removed the outer vinyl. Cut both the braid and the center conductor to 102". Hang the center conductor from wherever you can --tree, cieling etc. Plug the opposite end with the remaiing PL 259 into your radio and you're in business. I hang mine from the upstairs cieling in my bedroom and have skipped with this thing on sideband barefoot from inside the house. If you want to put it outside use a barrel connector to lengthen with another piece of coax or start with a 50 ft length. This is the ultimate stealth antenna and its a vertical. You'll also see that the SWR will be near perfect on channel 20. I put a small bend at the top of my center conductor and tied a small loop with fishing line to hang it with a thumbtack. I've also made antenna like this for 2 meters, six meters and 440 MHZ, They all work great. |
bruce
| | Posted on Friday, March 22, 2002 - 12:31 pm: |
|
The only refinememnt i can add to straycat's ant ( on any band )would be to at the bottom of the sheld put some rf beads to choke off the coax at the " feed point " other wise good point. |
Bigbob
| | Posted on Sunday, March 24, 2002 - 5:20 pm: |
|
Why not a coaxial ant. cut coating off braid,slide braid back slightly to belly it ,then roll it down outside of coax until you have 9'of center conductor and 9' of shield .you may tin shield to protect it and wrapp vinyl tape at center and shield juntion to waterproof.Leave dielectric on center wire and seal end.Thus you have a fairly desent ant. and no need for a match box. |
707
| | Posted on Friday, March 29, 2002 - 11:25 pm: |
|
ncrebel- chances are your local ham shop has a 10m dipole for around $15, complete with weatherproof feedpoint and insulators. It will work very nicely in the inverted L configuration without retuning for 11m. If you make it a sloper, vertical or horizontal, you might have to adjust the ends out a bit to tune it.
Here's how mine is set up:
http://dxring.net/srg.htm |
try anything
| | Posted on Wednesday, October 02, 2002 - 9:06 pm: |
|
Hi. We've tried a simple cable tv coax antenna.
It's simular to the coax and dipole antennas sugested above.
Depending on weather or not you want a 1/4, 1/2, or 5/8 wave antenna
For the moment we'll us a 1/4 wave which is 9 feet
in the CB 11 meter band.
a lenth of coax at least 10 feet long ( a little more would be helpful for the end that attatches to the CB and the top center of the coax is usualy twisted into a hook.
Stip off the outer sheeth from an end to the lenth of 10 feet 2 inches. This will reviel the braided copper mesh.
Now from the end (top end) remove 1 foot & 2 inches of braid.
Now strip off the 1 foot & 2 inches of the inner sheeth that is now exposed. The center copper wire is now exposed.
Twist 2 inches of the top of the center copper wire and make it into a loop (it's just something to hook onto a tree or rope).
Now you have a coax with a 9 foot braid and a 1 foot copper wire = 10 feet in total.
The 1 foot of center(usualy used as the "receive")
can be lenthened to basicaly any lenth so long at
the braid lenth is calibrated to match in order to limit Standing wave as much as possible.
The section to which a cb radio is attatched requires a bit of tweeking as a cb radio has an RG
-8 amphenol screw on connector. The Cable TV coax does not have a very large center wire.
Lastly depending on how you wish your antenna to
work. Either as an independant ground plane (isolated center/braid), or a pole type where the center and braid are connected via an impeedence circuit simular to what is found in an ex. Solarcon Imax-2000 antenna, or A99.
This paticular antenna is very light and compact, even more so than an dipole. You don't have to climb 30 feet up into a tree to set it up
either. All you do is roll it up and leave when done.
It does not cost much to build, and is a good way for any one starting in antennas to experiment .
P.S. Just in case it's not clear.
The braid will be "transmit", and the center will be "receive" depending on your desire of a ground plane or not. |
|
