collinear antenna 2G 930MHz - diy

Hi
I try to build collinear antenna at 930 MHz ....

I build like this:
http://cheatthezone.tripod.com/wireless/colinear.html
but instead 60mm _O_ 90mm _O_ 83mm _ measuring parts (at wifi f 2400MHz) I made racalculation at 930MHz and build with wires:
SMA connector =161mm _O_ 242mm _O_ 218mm
I have pure result! What is wrong?

Have anybody good point to make collinear antenna with simple wire and good gain?! (cca 6-9dBi)

Collinear vertical antenna is made by specific phase connected λ/2 elements.

λ at 930MHz is 322mm, which makes λ/2 to be about 161mm.

Usually at the connector input side, is used a λ/4 element (80mm in your case).