Two Element Yagi

For 10 Meters

by Tom - K1JJ

Here’s a simple 2 el Yagi which put up FIXED on a pole or chimney at 20’ or higher will give you the ability to cover a very wide 85 degree swath of the USA and beyond. Weighs less than 10 pounds. Aluminum tubing available at Texas Towers/ UPS… CHEAP! Guaranteed to work Hawaii and Australia. If not, well tough.

Here are the instructions, dimensions and taper schedule to build this SINGLE, simple 2 element Yagi for 10M.

The one shown below is computer generated mechanically and electrically. I have tested and use it now in a stack of three. If you’re “Type A”, you can add as many as you like to the first one later on.

It will cover 28-29.5 with a 1:5:1 SWR or less. It is very broadband and has a simple 50 ohm input for DIRECT feed. The boom is 1.5” diameter with a 6’ length. The beam will handle 130 mph winds and 1/2” of ice. Has about 10.5 dbi forward gain (4.5 dbd) and 15 db front to back.

The DRIVEN ELEMENT is split in the middle, connected DIRECTLY to the coax and mounted on a piece of insulated material. (PVC, fiberglass, heavy plexiglass, etc). The element sections slide together with two small 6-32 nuts and bolts through the joints to hold them together.

Coil up 5 turns of coax 6” in diameter at the feedpoint as a coaxial balun to prevent feedline radiation. Tape it to the boom. Use a small piece of copper flashing bolted to each driven element to solder the coax feedline to.

The following dimensions are for each ONE HALF of each element:

Driven Element sections:
EXPOSED lengths.

(Slide these sections together with a 2” overlap for each section inside on another)

1” tube - 18” long
7/8” tube - 18” long
3/4” tube - 18” long
5/8” “ - 18” long
1/2 “ “ - 34” long

Total: 98” long X2 halves = 196” total length (16.3’)

Make all pieces 18” long and insert 2” into the bigger element as overlap, making 16” total length sticking out. (Easy…Just cut the 6’ lengths into four pieces = 18” pieces) Use a 2” overlap for the 1/2” piece too.

Mount the reflector directly onto the boom using clamps and a small 6”X 4” aluminum plate. Use two clamps to hold the plate to the boom and two smaller clamps to hold the element to the plate. (reflector element is NOT insulated from the boom)

The dimensions for the reflector are exactly as the driven element above EXCEPT the 1/2” tips are 44” long. (Cut it 46” long and use a 2” overlap slide inside) Reflector overall length is 208”.

If you order one 6’ length for the 1.5” (boom)… and 6’ lengths for each of the 1”, 7/8”, 3/4”, 5/8” element tubes… and two 6’ pieces of the 1/2” tubes you will have enough for the whole project with minor waste. Texas Towers has these “drawn” tubes in stock that slide into one another and has the best prices. UPS ship-able.

Any questions, email me.





12 January 2002