Portable VHF/UHF Antenna System
with 18 Foot Push Up Pole
by Mark Coker - KC7JOG

For those that deploy, yet wish to accommodate VHF, or VHF/UHF without compromise, this project will certainly have appeal. My bronco has a diamond 770 dual band antenna, and, were I to deploy to a location, with desire for best possible omni VHF/UHF communication, this is the method I would choose. It allows portable, base station quality, with excellent performance in a portable design.

list of materials:

(1) 1 1/4" by 4' EMT Pipe
(1) 1" by 4' 5" EMT Pipe
(1) 3/4" by 4' 10" EMT Pipe
(1) 1/2" by 5' 3" EMT Pipe
(1) 4" by 4" by 1/8" Steel Plate
(1) 1/2" SO-239 bulkhead Mount Connector
(3) Small Chain Links
(3) 19.5" long pieces of
80S TIG Rod Wire		 .128 dia.
(3) 1/4 by 20 Nuts
(3) 1/4 by 20 bolts 1/2" long
(1) Bolt, any thread, 9/16" about 3" long
(3) ea 3/8" by 1" long Bolts,
3/8" Nuts		 same thread
(4) 1/4 by 20 Nuts
(4) 1/4 by 20 Bolts 1/2" long
about 40 feet RG-8X
(1) Diamond 770
*see note below		 Antenna
(3) ea Stakes and Guy Lines 10' long

* If a Mag Base antenna assembly is preferred, there is no need for the SO-239 bulkhead or the diamond dual band antenna.

Paint one end of the 3 smaller pipes with red paint; about 7 inches is fine.

4" down from the top of the 3 largest pipes, drill a 7/16" hole andweld a 3/8" nut over the hole. On the base pipe, weld the 3 chain links at the top, every 120 degrees. I welded short T handles on the ends of the clamping bolts, but this is optional.

Another close up, of the clamp bolt welding, as well as the guying rings, welded at the top of the base pipe.

Drill a 5/8" hole in the center of the plate, unless a mag base type antenna is chosen to use. Drill a 3/8" hole in each corner, then weld a 1/4 by 20 nut over the holes. Bend all four corners down; about a 45 degree angle.

Weld the large 9/16 bolt to the bottom of the plate. This fits snugly into the top section of the EMT pipe. Remember, if you've chosen a Mag Base type antenna, it will sit on the top of the plate, eliminating the need for the 5/8" drilled hole as well as the SO-239 bulkhead shown in the pictures.

Weld the 4 radials to the heads of the 1/4 by 20 bolts (4 TIG wires cut to 19.5 inches)

All the components laid out unassembled

Assemble the antenna platform, screw on diamond antenna, and hook up the coax.
Assembled in the down position...

Begin extending the pole to 18+ feet, after its been securely guyed at the top of the base pipe with guying cord tied to stakes placed about 8 feet away on all three sides. if you chose to use a Mag Base type antenna, merely add a barrel connector to the end of the Mag Base antenna coax, and continue with additional coax to reach your operating table.