© WB5CXC 2011
Constructing EH Antennas
Materials: 2” PVC Sch. 40 Pipe - Home Depot / Lowe’s Aluminum Roof Flashing Home Depot / Lowe’s Short 2” PVC coupling (3) Home Depot / Lowe’s Sheet Metal Screws #6 or #8 X 1/2” Home Depot / Lowe’s 2” PVC Cap Home Depot / Lowe’s Brass Bolts/Nuts #6 X 3/4” Home Depot / Lowe’s #14 Enamel Wire The Wireman
Building The Pieces: Cut two pieces of 2” PVC pipe 10 1/4” - 11”  (7 1/4” + 1 1/2” + 1 1/2” space for couplings) Cut two pieces of aluminum flashing 8 1/2” X 7 1/4”
Make two cylinders.  Wrap a piece of aluminum flashing around the PVC pipe leaving 1 1/2” at each end for the coupling.  Secure the flashing using #6 or #8 sheet metal screws.  It helps to have a helper during this part of the operation.  They can hold the flashing around the pipe until you get a couple of screws in to hold the flashing.  I drill a 1/8” pilot hole for each screw.  On the end of each cylinder drill a hole for the #6 or #8 brass bolt.  On one cylinder drill a small hole (~ 5/64”) next to the bolt, this will be top of the bottom section.  Take a piece of #14 enamel wire 14” - 16” long and scrape 1/2” of the enamel off one end.  From the inside of the cylinder place the wire through the hole and wrap it around the the bolt, and secure it with another nut.  This wire should be flush next to the inside of the cylinder. 
Drilling pilot hole for sheet metal screws
Completed Cylinder
Take one of the coupling and drill a 5/6” hole in the center of the coupling.  Cut a piece of #14 enamel wire 36” long.  Push 16” inside the hole and leave 20” exposed.  Now bend the wire as it comes out of the hole and wrap two turns around the coupling.  This will be your Phasing Coil.  I secure the coil with black tape until it is time to assemble the antenna.  Take a piece of 2” PVC pipe (~6”) long and drill a 5/64” hole about 2” from one end.  Cut a piece of #14 enamel wire 11’ long.  Scrape 1/2” enamel off one end.  Ben the wire at right angle 1/4” from the end.  Place the end in the hole and start winding your coil.  Use electrician’s tape to hold the coil in place after you have 4 - 5 turns. 
Assembly: Take a coupling that you wound the Phasing Coil on and measure the depth that the pipe will penetrate the coupling.  Now cut off the bottom of the top cylinder and glue it into the coupling (the outside wire should be close to the cylinder bolt).  Scrape 1/2” of the enamel off the wire and connect off the wire and connect it to the bolt on the top cylinder. 
Coupling connected to Top Cylinder
Now measure the depth of the coupling Z(Phasing Coil) and measure the distance that the bottom cylinder will have to be for a 1 diameter (2 3/8”) spacing.  Before gluing route the wire from the phasing coil down the center of the bottom cylinder.  The bolts on the cylinder should be on opposite side of each other (180 degrees). 
Using another coupling measure and cut the bottom cylinder and the top of the pipe with the tunning coil to have 1 diameter between the top of the coil and the bottom of the bottom cylinder. Now glue the coupling on and the bottom cylinder.  Drill a 5/64” hole next to the top end of the coil.  Route the wire from the phasing coil through the hole.  Scrape the enamel off the end and cut leaving ~ 1/4” (this need to connect to the top end of the coil) bend and solder to the top end of the coil.  Solder a short piece of coax (~1 foot) to the coil and the wie from the bottom cylinder.  Now we are ready to tune the antenna.  The center of the coax will be connected to the bottom of the coil and the shield will be connected to the wire from the bottom cylinder. 
Bottom Cylinder
Tuning EH Antenna
Completed Antenna
© WB5CXC 2004