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Mobile antenna for 27 Mhz

bejo

bejo

member From Indonesia
Jan 3, 2010
40
0
16
Malang, East Java - Indonesia
Dear all member,

can we get information for mobile homebrew antenna work at 27 Mhz..

we plan make homebrew antenna for mobile.

thanks for all kind support and information

bejo From Indonesia
 

Dear mr Quick Silver,

do you have detail information for your suggest ?

in our country is very difficult get mobile antenna from store...

so we want make by self

thanks for your quick response
 
I would think if you can find a thin stainless steel rod and cut it to 102" / 108" and mount it some how. Then find a way to connect coax to it, you would have an antenna of sorts. Can you order a setup of the internet? Might be able to get a setup from The Philippines. Good luck!
whip
lD1r.jpg


B102.jpg


mounts
IMG_6375.jpg


40753921_8778550_full.JPG


aug315661vx.jpg
 
An antenna for 27 Mhz (or any other frequency) has to be an electrical conductor. From there, it can be of almost any 'shape', wire, or a metal rod which will stand up by it's self. Using simple wire means that you have to provide the support for that wire, bamboo for instance, or any other non-conducting device or material.
1/4 wave antennas, which are usually the shortest usable length without adding a coil to the antenna, is dependent on on the frequency of use. A very rough means of finding that length is by dividing '234' by the frequency in Mhz, which will give you length in feet. It will also be slightly too long, which means that it will have to be "trimmed" to the correct length, which is usually referred to as 'tuning' the antenna.
In making an antenna, your imagination is very useful!
- 'Doc
 
Thanks sir for your advice
actually I am allready calculate with 1/4 wave length with formula 300/f (Mhz) = wave length (meter), but i see the whip is to high (2.75 meter) , so if any suggestion from senior member or all member , please give me advise for length whip not to high

thanks...
 
i cannot guarantee that this will work, but here are the dimensions of the wilson 1000 antenna.
maybe you can find the materials and make your own version.

start by getting some 12ga. solid copper wire.

wind 5.5 turns around a 1.75 inch form.
space the turns about .25 inch apart, so that the whole coil ends up being about 2 inches long.

use a vertical whip that is about 66 inches long. (you may have to shorten it later, but its always better to start out too long)

solder the center conductor of your coax to the bottom of the coil.

connect the shield of the coax to the vehicle body.

using a very short (about 1 inch long) wire, connect the vertical whip to the top of the coil about 4.5 turns up from the bottom.

before you start cutting length off of the whip to lower the SWR, try moving the point on the coil where the whip is attached.
once you get that to the point where the SWR is the lowest, solder it in place and then fine tune the SWR by adjusting the length of the vertical whip.

if SWR is higher on channel 1 = whip is too short

if SWR is higher on channel 40 = whip is too long

always adjust in .25 inch increments.

remember that this antenna is designed to work in the US CB band from 26.965 to 27.405.

try to make it look something like this:
 

Attachments

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Ya, panjang 1.7M adalah tentang hak untuk antena gelombang 1 / 4. Jika Anda perlu untuk lebih pendek, Anda akan perlu membuat sebuah kumparan kawat di bagian bawah. Anda harus bereksperimen dengan jumlah dan diameter berubah untuk memiliki kecocokan yang baik untuk kabel Anda gunakan.

Thank you, Google.:D
 

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