Hello,

i would like to make my own antenna for CB radio, mostly because i am
interessted in the technics involved, not strictly because of saving
some money.

I was googling a while but unfortunately the information i gathered was
rather unsatisfactory. Quite some theory but lack of practical descriptions.


Are there good links to pages how to make it's own antenna?


I am interessted in an antenna which gives me a good trade of between
gain, ease of operation and ease of manufacturing.

I think now that either a "long wire antenna" or a dipole would be the
best for my purpose. I would place both vertically on a fishing rod.
A horizontal adjustment would yield better results in DX but not so good
results for near communication, right?

But i wonder how i can make a balun on my own. I guess i need a 1:1
balun for the dipole (i use rg58 to the radio) or a 1:4? balun for the
long wire.

Would the two antenna types be a good choice?

Any help would be appreciated.

Greetings,
Johann

http://www.citizensband.iofm.net/equip/antenna.php

stuff about CB antennas how to trim / tune,
not to technical.

http://www.citizensband.iofm.net/projects/dipole.php

http://home.att.net/~wizardoz/cbmw/a...abri.html#doit

Dan/W4NTI wrote:
Get yourself a empty can of coffee. Place a light bulb in it. Hook the
coax to it. Remember the shield goes to the negative of the bulb.

Seal the can with lead solder.
Bury 15 feet underground.

Enjoy.

Dan I think you forgot to mention it has 20DB GAIN.

Can you use a crisco can? I have a lot of those laying around from our
crisco slather partys.

YES you can, and if you use a Bunch of them wired in series you get more GAIN,
figure 10DB more Gain for each CAN

Hal Rosser wrote:

You'll find a simple dipole may be your best choice for starting out.
Most important of all is to get the antenna up high and use vertical
orientation.
If I recall, each leg of the dipole should be around 102 inches.

102 inches, or 2.59 m for a metric man like me. That's right. But i
bother how i can go from balanced to unbalanced. I use rg58 wire and i
do not want to radio interfere my neighbours nor let my radio go up in
smoke.

So i guess i need a balun. The impedance at the connector from antenna
to wire should already be more or less 50 ohms, but it's balanced.

What would make an easy though effective 1:1 balun?

Gidday Johann

Simple balun you can use in this case is a "choke" balun. Just wind
about 5 turns of the coax in a 100-150mm circle near the antenna
feedpoint and tape it up. This will almost eliminate all of the line
radiation.

Another way is to make a folded dipole. This has a nominal 300 ohms
input impedence and feeding this with a 4:1 coaxial balun (200 ohms) is
only a slight mismatch. (1.5:1 VSWR) I have also heard (but never
checked/proven) that a folded dipole antenna couples to "space" better
than a simple dipole. (ie is more efficient)

If you cant find an internet refernce to the above then pls ask for more
info.

Cheers Bob VK2YQA

Johann Höchtl wrote:


Hal Rosser wrote:

You'll find a simple dipole may be your best choice for starting out.
Most important of all is to get the antenna up high and use vertical
orientation.
If I recall, each leg of the dipole should be around 102 inches.


102 inches, or 2.59 m for a metric man like me. That's right. But i
bother how i can go from balanced to unbalanced. I use rg58 wire and i
do not want to radio interfere my neighbours nor let my radio go up in
smoke.

So i guess i need a balun. The impedance at the connector from antenna
to wire should already be more or less 50 ohms, but it's balanced.

What would make an easy though effective 1:1 balun?

Johann wrote:
"A horizontal adjustment would yield better results in DX but not so
good results for near communication, right?"

To reach beyond line-of-sight but not very distant locations, usually
requires a reflection from the ionosphere nearly directtly overhead.

Vertical antennas tend to have a null directly overhead and tend to
behave poorly for areas beyond line-of-sight that require an ionospheric
reflection nearly overhead.

Low horizontal wires radiate substantial energy as antennas at high
angles to the horizon, and thus they are suited to reaching areas
beyond the horizon.

Best regards, Richard Harrison, KB5WZI

Johann wrote:
"A horizontal adjustment would yield better results in DX but not so
good results for near communication, right?"

To reach beyond line-of-sight but not very distant locations, usually
requires a reflection from the ionosphere nearly directtly overhead.

Vertical antennas tend to have a null directly overhead and tend to
behave poorly for areas beyond line-of-sight that require an ionospheric
reflection nearly overhead.

Low horizontal wires radiate substantial energy as antennas at high
angles to the horizon, and thus they are suited to reaching areas
beyond the horizon.

Best regards, Richard Harrison, KB5WZI