Simple CB Base Station Antenna

153,322

61

41

Introduction: Simple CB Base Station Antenna

About: I am a retired old geezer with way too much time on my hands for my own good.

This is a simple base station CB antenna You can make in 30 minutes out of a bit of PVC pipe and fittings, some wire and a SO239 coax connector and a piece of coax to connect it to your radio. You should have a 1.5 SWR on this. You should be able to build this for about 10 to 15 dollars.

Step 1: Materials

MATERIALS
2 PCS 8'6" 12 or 14 gauge electrical wire 
10' 3/4 Schedule 40 PVC pipe
3/4 inch PVC pipe cap
SO239 coax connector (see picture)
4 - screws or bolts to fit the SO239
I solder on eye electrical connector to fit screws on SO239 and wire
20' section of 1.5 inch Schedule 40 PVC pipe.
1 - 1 1/2" PVC "T"
1 - 1 1/2" PVC cap
1 - 1 1/2" x 3/4 PVC reducer

TOOLS
PVC cement
saw
drill
screwdriver
pliers
Soldering gun and electrical (NO acid) solder
electrical tape
sealant

Step 2: Assembly

1- Strip back 1/8 inch insulation on wire and solder to center of SO239. Make sure solder joint is shiny. If it is dull, reheat it till thoroughly melted.
2- Solder electrical connector to end of second wire.
3- Drill hole in Cap to mount SO239 flush. Then drill mount holes for mounting screws.
Cut off 1 1/2 to 2 inches off the end of the 1 1/2 inch PVC pip[e and glue into base of T to mount cap (as shown in picture). Do not glue cap yet. Drill small hole in under side of the T for wire (see red wire in picture)
Glue in 1 1/2 x 3/4 reducer on top of the T
4- Insert wire that is soldered to SO239 into hole in cap then mount SO239 to cap with screws and a little sealant. Put eye of other wire under one of the screws. Tighten and put a little sealant over screw with wire under it.
5-  insert wire under screw into hole on bottom of T (see red wire in picture) and out the bottom of the T 
6- Insert wire soldered to SO239 in T and out the to 3/4 inch hole in top and glue cap to T.
7- drill hole in 3/4 pipe cap for wire.
8- cut a piece of 3/4 PVC about 8 feet so the wire will go through it, out the cap and have enough to tie a knot about 2 inches from the end. Glue it together.
9- run the remaining wire down the log PVC pipe and glue T to the pipe.
10- Attach lead in cable to SO239 and tape to protect from weather. Also tape to outside of antenna pole to keep it from whipping around in the wind.
11- Glue T to 20 foot section of 1 1/2 inch pipe.

Step 3: Set SWR

My radio has an swr meter on it, if yours doesn't you will have to borrow or buy one. 

Your antenna should be away from metal objects.
If you want a taller mast use a metal pole or use guy wires.

The SWR should be ok with this if your solder joints are good. 

Read your directions for checking the swr. Some meters you have to zero. mine is automatic when it is in the swr mode on the radio. I just have to key the mike to see the swr.

Check your SWR on channel 1 and 40. It should be around 1.5 across the band. If it is over three, you need to adjust the length a little bit at a time. If it is higher on 40 you need to shorten the tip about a quarter to half inch at a time. If it is high on 1 you need to solder a little on the end to make it longer. I have made about 20 of these and I haven't had to add anything to it. Most of the time I don't have to do anything to it.

Step 4: NOTES

NOTES
You can improve the range by making 4 horizontal reflectors 8'6" long below the T connected to the screw of the SO239, but this supposed to be simple and easy version. That gets more complicated.

If there isn't any skip, I can usually talk about 10 to 20 miles easily.

If you have a lot of trees around you, they can cut down on your distance too. You can put your antenna in the top of a tree to get height but make sure it is above the leaves.

It is a good idea to put a lightning arrestor in your coax someplace between the radio and the antenna. Also ground the chassis of the radio. It will also help you get out a little better. I have logged 16 different countries including australia on homemade ground planes, not because the antennas were some great invention or secret, it was because I had a very good ground. You can have a thousand dollar antenna 500 feet in the air but if you have a bad ground, you won't talk across town. I used to take my motorcycle with a 102 inch whip down near the salt water and throw a ground wire in the salt water and talk 40 miles down the coast from my motorcycle. Granted there were no trees but motorcycles have almost zero ground so they do good to talk a couple of miles at best. If you are around Bradenton Florida, go down on channel 2 and ask around for somebody who remembers Machismo. They will tell you I did that all the time just south of Tarpon Springs to Anna maria island. I also talked regularly from just north of Key West to Bradenton. over 100 miles because I had a copper ground plate under the boat in the salt water

FOR BEST RESULTS, MAKE SURE YOUR RADIO IS GROUNDED PROPERLY. IT WILL IMPROVE THE RANGE.

OK that is it, quit reading and get to work.
Later
Machismo.

Weekend Projects Contest

Participated in the
Weekend Projects Contest

2 People Made This Project!

Recommendations

  • Puzzles Speed Challenge

    Puzzles Speed Challenge
  • "Can't Touch This" Family Contest

    "Can't Touch This" Family Contest
  • CNC Contest 2020

    CNC Contest 2020

41 Discussions

0
electric guy
electric guy

4 years ago

is there a limit (by law) for how big to make it?

0
Len_NJ
Len_NJ

Reply 5 months ago

This antenna is specific to the CB band (27 mhz or 11 meters). Remember - the band you are transmitting on determines the length of your antenna. So . . . by "HOW BIG", I'm assuming you mean HOW HIGH can you fly this antenna....right?

There are federal limits to erecting antenna masts. I would reccommend
not going more than 40 or 50 feet straight up. Be VERY AWARE of the proximity of POWER
LINES and such, because if it comes down, it might hit power or
phone/cable line(s). Don't forget to use GUY WIRES to prevent it from
swaying in the wind.

0
rbodell
rbodell

Reply 1 year ago

Watch for aircraft LOL. You can put it as high as you want (within reason) but changing the length of the antenna changes the frequerncy. and can mess up your radio.

0
rbodell
rbodell

Reply 4 years ago

By how big, you could mean the length of the antenna or the height above the ground. The diameter of the antenna is fixed. By changing the lingth of the antenna. you will change the frequency. The more you change the diameter the more the signal will be degraded.

As for height above the ground, The higher the antenna. the better it will work However there are restrictions on height in some areas. If you live close to the flight path of an airport, call the airport and tell them where you live and they can advise you on height restrictions. You can also call your city and see if there are any other height restrictions for your area. If you belong to a homeowners association, check with them. Some do not permit antennas or towers. At some point you will be required to have a light on top to warn aircraft of it's presence. Pretty much everywhere, you are restricted to 500 feet so it does not interfere with aircraft as they stay above 500 feet except for landing or take off..

In most areas you have to have room if it falls, it will stay on your property. In other words, if you have a 200 foot tower it must be at least 200 feet from your property line. A 1 acre piece of property is approximately 200 feet by 200 feet, so you would be limited to 100 feet if it is in the center of the property.

0
MichaelK302
MichaelK302

7 months ago on Step 1

Hello I know this is an old post. Would this antenna perform better if the ground wire is extended to a proper earth ground?

0
Len_NJ
Len_NJ

Reply 5 months ago

No. it will work just fine as indicated.

0
MichaelK302
MichaelK302

Reply 7 months ago

The soldered wire goes up to the 3/4" PVC. The ground wire attached to the screw goes down the 1.5" section.

0
jerry.ericsson2
jerry.ericsson2

Question 1 year ago

Sounds like a poor man's RC292 from my old days in the US ARMY, we could reach out and talk to folks with one of those rigs, but we needed adjustable so we had regular screw together antenna parts, with three ground plane antennas on the out side. This looks much easier, and should not need as much guy wire tie down. I plan on putting one together, as I found a used base station last year down in Arizona, now that I am home in SD, I think I will set up a CB Base. I also have my Ham ticket, so I may try and set up a 2 meter version for one of my 4 2 meter rigs as well, perhaps I can hit a distant repeater with a good 2 meter antenna as well. Have to do some calc to find the proper length of wire for that antenna

0
hduperly
hduperly

5 years ago

The electrical wire that is attached to the screw hole of the SO239 then goes down the t connector then what did it attach to? Does it just hang there or is it attached to the ground rod driven into the earth?

0
rbodell
rbodell

Reply 1 year ago

The higher the frequency the shorter the antenna

0
rbodell
rbodell

Reply 1 year ago

Just the length of the wire. The pvc has nothing to do with it but hold up the wire

0
rbodell
rbodell

Reply 4 years ago

It just hangs there

0
matnor
matnor

2 years ago

Which frequency/band suitable for this antenna?

0
rbodell
rbodell

Reply 1 year ago

cb frequencies

0
william osborne
william osborne

Question 2 years ago on Introduction

do i need to ground my base station inside my house,i run on 12 volts

0
rbodell
rbodell

Answer 1 year ago

yes

0
allansplace
allansplace

3 years ago

Thanks, rbodell! Great instructions. Who'd have thought a radio antenna could be so easy - and cheap.

I have some questions. Hope you don't mind.

1.
To trim the antenna, I will cut off a piece from the 3/4" PVC. Will I
also cut the top of the wire, or is letting it hang there alright?

2.
I have a Stryker SR-955HPC 10-meter band export radio (HAM) that also
does 11-meter (CB). For 10-meter, will I lengthen or shorten this
antenna?

3. How do you soldier? Just kidding.

Thanks again for the instructions!

0
hakforfun
hakforfun

4 years ago

Do you have a wiring diagram or something? I can't quite understand howto wire this up.

0
rbodell
rbodell

Reply 4 years ago

the center conductor of the so239 is
soldered to the antenna wire going up. The outer connector of the so239
is where the ground/reflector wire and just passes through a hole to the inside of
the mast and hangs down the inside of the mast.

http://www.k4icy.com/dipole_connector_so239.jpg