Aluminum ground plane

[wavrider]

1/2 inch emt conduit.

I have built 5/8 wl GP out of all EMT conduit and have a four element JO Gunn copy built out of 3/4" EMT conduit, both work well and the material is inexpensive.

 

[Robb]

1/2 inch emt conduit.

. . . the material is inexpensive.

Yup
REAL cheap and easily available too . . .

 

[Meglotron]

add length to it until it's 22' 4" long. now its a 5/8 and will have about a 150ohm impedance instead of the 2500 ohm you find with a half wave. go 10 turns of wire from the ground plains bracket to the main element and about 3-5 turns up from ground is where you should find the 50 ohm tap point. now you have a 5/8 with even more gain