Build you own 4:1 Balun for a Delta Loop Antenna

I recently decided to build a Delta Loop Antenna for 10 meters but  if  a  20 meter version would fit into my yard then I will build the 20 meter version.  Why a 20 meter version?  Well this band carries most of the amateur radio DX traffic and it will also allow me to use it for other bands below 20 meters but then I need to use an antenna tuner.  To match the antenna for 20 meters I decided to build a 4:1 Balun.  Now there is quite a few methods to build the 4:1 Balun.  I decided to build the air-cored version which does not use a toroid but just a piece of pipe and some wire.  Please note the version I describe hear is for low power QRP use for up to 20 watts.  If you would like to build a 4:1  one hundred watt or higher Balun, just use thicker wire that are able to handle the power you will run.  For this topic I will not discuss the build of the Delta Loop Antenna in itself.  This will be done in a separate posting to follow soon.  Let's get cracking!

Here is your list of materials:

1.  22 - 30 mm of PVC pipe. 120mm in length  I used 22 mm water pipe as this is all I had
2.  2 x Electrical Lugs
3.  1 x SO239 Connector 
4.  2 x Stainless Steel Bolts and Nuts to install SO239
5.  2 x Stainless Steel Bolts and Lock Nuts to connect the lugs to
6.  2 x Stainless Steel Bolts and Nuts to connect the lugs to
7.  2 x Stainless Steel Wingnuts to connect the lugs to
8.  1 x 40 mm PVC pipe to cover the balun
9.  2 x 40mm PVC End Caps to cover the balun
10.  4 x Stainless Steel Self tapping Screws 12mm long
11.  2 Pieces of heat shrink tubing to cover the two wires that comes out of the PVC cover.
12.  Hot glue Gun + Hot glue
13.  Marine Aqua 
14.  1 x Small Electrical Lug to connect ground to SO239 connector.
15.  1.2 meter of electrical red and black twin flex wire.  Wind 16 turns on 22 - 30mm PVC pipe.
    

I am not going to describe how to build this balun as the diagram and images explain everything in detail.  (Click on images for larger view.)

Finally seal all openings were water can get in like the End Caps,  the side holes were connections were made,  SO239, self tapping screws and bolts and nuts.  When finished you will have a 4:1 balun that will cost you under R100.00.  I will give an overview of the working of this balun as soon as I can put it to a test. Stay tuned!