KG5DCM ENCLOSED "UGLY BALUN"
Most of you may be familiar with the standard HF "Ugly
Balun" but this fairly simple project will show you my ideas for one that
is enclosed and out of the weather.
You may modify any or all of these
instructions to suit your needs and skills.
Just make sure to use
the coax length of about 18 to 20
Finished with paint job and
Materials list and description of
14" of 4" PVC. (all pvc is schedule 40 unless
2 - 4" PVC caps
1 - 1
1/4" PVC coupling
2 - PL-259 male
2 - SO-239 barrel or female
18'-20' RG8 cable
#6 or #8 self-tapping screws
small scrap piece of 1/2"
I began by turning the 4" caps
on a lathe to drill large holes in the ends for 1 1/4" pvc conduit.
Realizing not everyone has access to a lathe but a correct size
hole-saw will do the job.
Make the TOP cap hole a snug
fit for a 1 1/4" coupling. The bottom cap hole can be whatever you want to
use that will fit up a 1/2" CGB connector for the coax lead to
exit thru. But you want it large enough that the PL259 will go thru it. In
case you don't know what a CGB connector is..see photo
Glue the 4" PVC into the BOTTOM
CAP. Slide the TOP Cap onto the 4" only far enough that you can
get it off again and drill 3 holes equal-distance around the
circumference. (Be sure to make one of them as a "match line" )
Now you are ready to coil up
the coax inside the tube. I wrapped the 20' length of coax around a short
piece of 2" pvc and taped it in place overnight.
Next day I
released the tube and let it un-coil. After running enough out the bottom
hole to install a PL259, start coiling the coax a few coils at a time and
pressing it down firmly. Make sure each new coil is firmly seated against
the last one in the tube. At the end of the coiling process tie the final
coil off with a bolt or screw so it can't release and come out. Install
PL259 on each end (or whatever connector you plan to use). When installing
the coil, be sure to thread the CGB
connector onto your coax (from the
radio) before installing the PL259.
with both ends, the CGB connector can be "screwed" up into the 1/2
pvc (see picture) mounted in the bottom and the coax connectors will be
inside the tubing out of the rain and weather. I have 3 screws
mounted into the 1 1/4" conduit under the top cap to keep it from sliding
down---this holds the whole unit up and takes all the weight of the balun.
I also drilled a few "weep" holes around the bottom cap where the CGB
connector is to allow any drainage out.
can certainly modify the materials used in this project to fit your needs
and use your own methods to get the desired results for an enclosed "ugly
balun" and I hope this simple article will give you some ideas that you
can work with....73 John, KG5DCM
Email me for any questions you may
have to john.riddle62 AT